Search

Background: Urdbean leaf crinkle is one of the serious diseases of urdbean [Vigna mungo (L.) Hepper] which is caused by an ungrouped virus called Urdbean leaf crinkle virus (ULCV). The disease is highly seed transmissible under natural conditions and in experimental conditions it is mechanically transmitted through sap inoculation. Methods: The aim of this study was to standardize the protocol for sap inoculation by sprout seed abrasive method by comparing the effects of different inoculation methods, such as pin prick and without pin prick, with 0.05M potassium phosphate buffer (pH 7.0) supplemented with additives and abrasives and to further validate the standardized protocol upon different urdbean genotypes. Result: This is the first effort on the optimization of protocol in which, pin pricking as inoculation method with potassium phosphate buffer (0.05M, pH 7.0) supplemented with 0.15% sodium sulfite+0.01M 2-Mercaptoethanol and 1% celite+2% carborundum showed 100% transmissibility foremost at 2nd trifoliate stage and further validation with various urdbean genotype resulted in percent transmission ranging from 92 to 100% which evinces the efficacy and repeatability of the methodology. [ABSTRACT FROM AUTHOR]

cis -(+)-12-Oxo-phytodienoic acid (cis -OPDA) is a significant plant oxylipin, known as a biosynthetic precursor of the plant hormone jasmonoyl- l -isoleucine (JA-Ile), and a bioactive substance in plant environmental stresses. A recent study showed that a plant dioxygenase, Jasmonate Induced Dioxygenase 1 (JID1), converts cis -OPDA into an unidentified metabolite termed "modified-OPDA (mo-OPDA)" in Arabidopsis thaliana. Here, using ultra-performance liquid chromatography coupled with triple quad mass spectrometry (UPLC-MS/MS) experiment, the chemical identity of "mo-OPDA" was demonstrated and identified as a conjugate between cis -OPDA and 2-mercaptoethanol (cis -OPDA-2ME), an artifact produced by Michael addition during the JID1 digestion of cis -OPDA. However, previous reports demonstrated a decreased accumulation of cis -OPDA in the JID1-OE line, suggesting the existence of an unknown JID1-mediated mechanism regulating the level of cis -OPDA in A. thaliana. [ABSTRACT FROM AUTHOR]

Developing proton-exchange membranes (PEMs) for energy applications is necessary for fulfilling the increasing energy demand without environmental effects. In this study, we prepared composite membranes containing mercaptoethanol-assisted sulfonic acid-functionalized polysiloxanes (MASFPs) and perfluorinated sulfonic acid (PFSA). The MASFP-containing composite membrane (i.e., CMASFP-2) exhibited better membrane properties than the composite membrane prepared without mercaptoethanol (CMASFP-1) and the reference Nafion 212 membrane. Wide-angle X-ray diffraction (XRD) studies revealed a broad peak at 2θ = 17.4° and 39°, indicating that the composite membranes are semicrystalline. Scanning electron microscopy (SEM) analysis revealed that the prepared composite membranes had good morphology, whereas energy-dispersive X-ray spectroscopy analysis revealed that it had siloxane and more sulfonic acid than the pristine PFSA membrane. Thermogravimetric and mechanical strength analyses revealed that incorporating sulfonic acid-functionalized siloxanes improved the thermal stability and mechanical strain of the membrane. The prepared CMASFP-2 membrane had a high ionic conductivity of 0.106 mS cm−1 and an ion-exchange capacity of 1.09 meq·g−1. CMASFP-2 also exhibited lower hydrogen gas permeability than the Nafion 212 and PFSA membranes, demonstrating that it can be used for energy applications. [Display omitted] • A new sulfonic acid-functionalized siloxane was used in composite membranes with PFSA. • The addition of mercaptoethanol enhanced the sulfonic acid amount in the siloxanes. • The CMASFP-2 membrane had a better ionic conductivity and ion-exchange capacity than Nafion 212. • The addition of siloxane improves mechanical strain and lowers H 2 gas permeability. [ABSTRACT FROM AUTHOR]

In this study, ethanolamine and 2-mercaptoethanol were tested for the first time as capping agents and heteroatom sources in the preparation of heteroatom-doped reduced graphene oxides (Au/E@rGO and Au/M@rGO) decorated with Au nanoparticles that can be used as catalysts in ethylene glycol (EG) fuel cells. The performance of the composites was compared with the composite prepared at the same conditions using sodium citrate dihydrate (Au/C@rGO), a widely used capping agent in the literature. The average particle size of Au nanoparticles in Au/E@rGO, Au/M@rGO, and Au/C@rGO were calculated as 10.55 ± (5.10) nm, 5.82 ± (2.35), and 3.36 (±1.02 nm) based on the TEM analysis, respectively. Amounts of Au loaded to Au/E@rGO, Au/M@rGO, and Au/C@rGO were determined as 36.50 (±0.51) %, 39.04 (±1.13) %, and 27.66 (±0.08) %, respectively. The EG oxidation performance of Au/E@rGO was 5 and 14 times higher than that of Au/C@rGO and Au/M@rGO. Chronoamperometry measurements showed that Au/E@rGO, Au/C@rGO, and Au/M@rGO catalysts retained 18.72%, 7.31%, and 4.06% of their initial currents, respectively, revealing that Au/E@rGO maintained its stability significantly compared to Au/C@rGO and Au/M@rGO. Repetitive cyclic voltammetry measurements also verified the high stability of Au/E@rGO in EG oxidation. The results showed that ethanolamine can be used as a potential capping and N-doping agent in the preparation of carbon structures containing Au nanoparticles that can be used in fuel cells. [Display omitted] • Ethanolamine, 2-mercaptoethanol, and sodium citrate were tested as capping agents. • N and S doped-rGOs decorated with Au nanoparticles were prepared for EG oxidation. • Au/E@rGO and Au/M@rGO were tested as catalysts for the first time in EG fuel cells. • Among the tested substances, ethanolamine has the best performance in EG oxidation. • The stability of Au/E@rGO was prominently higher than that of AuM@rGO and AuC@rGO. [ABSTRACT FROM AUTHOR]

Heavy metals like lead are highly toxic to human health and the environment. In this work we report a simple, reproducible and low-cost method to obtain a colorimetric nanosensor that selectively detects lead II in aqueous medium. The sensor is based on silver nanoparticles functionalized with 2-mercaptoethanol. Metallic nanostructures were obtained by the chemical reduction method. The X-ray diffraction spectra showed the face-centered cubic structure of the silver nanoparticles. The size of the crystallite was found to be 10 nm using Scherrer's equation. The colorimetric method takes advantage of the localized surface plasmon resonance properties of the metallic nanoparticles. Under alkaline conditions, mercaptoethanol helped to selectively detect Pb2+ over other metals, including As3+, Cd2+, Mg2+, Fe3+ Ca2+, and Na+ y K+. A color change from yellow to bluish was recorded in the sensor when were mixed with lead ions. The experimental conditions allow carried out precipitation process in 8 min. On the other hand, the absorption spectra of lead samples were obtained by UV–Vis spectrometry to determine the detectable range of lead concentration, which was 0.04 μg/ml. [ABSTRACT FROM AUTHOR]

The immobilization of ficin extract (sulfidryl proteases) on glyoxyl agarose beads stabilized it, but there is a clear stability maximum after 3 h of immobilization, being the 24 h biocatalyst less stable when thermally inactivated in presence of air. The incubation of the thermally inactivated biocatalysts in the presence of dithiothreitol permitted to recover almost total activity of the biocatalysts prepared for 24 h of immobilization, while the enzyme immobilized for 3 h recovered less activity. This suggested that the main cause of the faster enzyme inactivation of the 24 h biocatalyst was the Cys oxidation. This was confirmed by inactivating the Cys blocked biocatalysts by using 2,2′-dipyridyldisulfide. Again, a higher percentage of the initial activity (when unblocked by incubation in mercaptoethanol the thermally inactivated biocatalysts) was observed for the 24 h biocatalyst. The use of helium atmosphere enabled to greatly improve the enzyme stability of all immobilized biocatalysts, confirming the highest stability of the biocatalyst immobilized for 24 h. Results suggested that this biocatalyst was in fact the most rigid one, but that the distortion induced by the immobilization produced a higher exposition of the catalytic Cys, and this way, its oxidation becomes faster in the presence of oxygen. [Display omitted] • Ficin was immobilized on glyoxyl-agarose. • The enzyme stability increased when the immobilization time increase until reaching a clear maximum. • It has been shown that this is due to the faster oxidation of the Cys. • In absence of oxygen, the longer the incubation time, the longer the enzyme stability. [ABSTRACT FROM AUTHOR]

The effects of transglutaminase (TGase), reductant, and thermal treatment on the cross-linking of white proteins in soft-shell turtle eggs were investigated. Egg white proteins were denatured by reductant (0.83% 2-mercaptoethanol, 2-ME) pretreatment and thermal pretreatment (95 °C and 5 min), and the denatured proteins were then catalyzed by TGase (1.0 unit/mL). SDS–PAGE showed that without any pretreatments, three major egg white proteins (210 kDa, 115 kDa, and 76 kDa proteins) were inferior substrates for TGase. Only portions of the 210 kDa protein (7.9%), 115 kDa protein (11.4%), and 76 kDa protein (42.9%) were polymerized by TGase into high-molecular-weight (MW) protein polymers (>180 kDa) after incubation for 3 h at 40 °C. However, the combined use of TGase with 0.83% 2-ME and thermal pretreatment led to a significant increase (p < 0.05) in the rate of white protein polymerization after 3 h: 210 kDa protein (90.8%), 115 kDa protein (69.5%), and 76 kDa protein (72.2%). Particle size analysis indicated that these cross-linked high-MW protein polymers were 2000–10,000 nm in size. Based on the experimental results, egg white proteins denatured by 2-ME and heat pretreatment are more prone to TGase-induced cross-linking. [ABSTRACT FROM AUTHOR]

Mercury, a persistent, mobile, and toxic pollutant, often contaminates soils due to mining activities. This study investigates the use of thiol-modified biochar derived from olive stones to immobilize mercury in a tailings-contaminated soil sample from the National University of Engineering, Peru. The soil, characterized by high heavy metal concentration, acidic pH, and sandy composition, underwent a 10-week incubation with varying biochar amounts, leading to a 53-73% immobilization of the available mercury. The primary immobilization mechanism could be attributed to complexation between biochar functional groups and soil mercury. Results confirmed biochar addition progressively reduced mercury concentration. Despite thiol addition reducing the biochar's specific surface area due to pore clogging, the surface functionalization was successful, evident from chemical analysis. However, decreased fixed and elemental carbon content likely resulted from the initial feedstock content and pyrolysis conditions. Our findings suggest thiol-modified olive stone biochar as a promising, cost-effective solution for mercury immobilization in contaminated soils. [ABSTRACT FROM AUTHOR]

Most of cell penetrating peptides (CPPs) are rich in positively‐charged amino acids but the cationic property may provoke possible problems in practical applications. In this study, we carefully substituted the hydrophobic amino acids in the SAP(E) sequence, a rare example of negatively‐charged proline‐rich CPP, with cysteine for enhancement of cell penetrating activity as well as reversible conjugation of cargo molecules. Most substituents showed almost negligible cell penetrating activity, but a cysteine substituent on the 7th valine (SAP(E)‐7C) showed more improved cell penetrating activity than SAP(E). When treated to cells, the negatively‐charged SAP(E)‐7C exhibited much lower degree of co‐localization with acidic endosomes or lysosomes compared to positively‐charged TAT. SAP(E)‐7C could significantly enhance the PTX efficacy on MDA‐MB‐231 cells by non‐covalent complexation with PTX. As a proof‐of‐concept for covalent conjugation of cargo drugs, mercaptoethanol, a model drug, was conjugated to the cysteine residue of SAP(E)‐7C via a disulfide bond, and the glutathione‐dependent release from the conjugate was confirmed. The negatively‐charged SAP(E)‐7C with a cysteine handle can be a useful molecular module for the development of CPP‐based drug delivery carrier. [ABSTRACT FROM AUTHOR]

From whole tissues to single-cell lysate, heterogeneous immunoassays are widely utilized for analysis of protein targets in complex biospecimens. Recently, benzophenone-functionalized hydrogel scaffolds have been used to immobilize target protein for immunoassay detection with fluorescent antibody probes. In benzophenone-functionalized hydrogels, multiplex target detection occurs via serial rounds of chemical stripping (incubation with sodium-dodecyl-sulfate (SDS) and β-mercaptoethanol at 50-60 °C for ≥1 h), followed by reprobing (interrogation with additional antibody probes). Although benzophenone facilitates covalent immobilization of proteins to the hydrogel, we observe 50% immunoassay signal loss of immobilized protein targets during stripping rounds. Here, we identify and characterize signal loss mechanisms during stripping and reprobing. We posit that loss of immobilized target is responsible for ≥50% of immunoassay signal loss, and that target loss is attributable to disruption of protein immobilization by denaturing detergents (SDS) and incubation at elevated temperatures. Furthermore, our study suggests that protein losses under non-denaturing conditions are more sensitive to protein structure (i.e., hydrodynamic radius), than to molecular mass (size). We formulate design guidance for multiplexed in-gel immunoassays, including that low-abundance proteins be immunoprobed first, even when targets are covalently immobilized to the gel. We also recommend careful scrutiny of the order of proteins targets detected via multiple immunoprobing cycles, based on the protein immobilization buffer composition.

S‐Vinyl monomers react readily in radical polymerizations resulting in polymers with interesting features such as enhanced refractive indices, increased thermal stability, or the ability to coordinate various metals. Among them, vinyl mercaptoethanol (VME) can be produced in industrial scale, but the poor solubility of the resulting homopolymer limits its application. In this contribution, polymerizations of the monomer are investigated in water forming a heterogeneous system. The good solubility of the monomer in water imparts the system with mixed characteristics between a precipitation and an emulsion polymerization. Evaluating various surfactants, only polyvinyl alcohol (PVA) is found to create stable dispersions, although micrometer‐sized particles are formed with a broad size distribution. Nevertheless, the particles are able to coordinate silver or gold ions. Attempts to reduce the noble metal ions by commercial reducing agents fail. However, exposure to sunlight unexpectedly results in a controlled reduction of the metal ions and the formation of composite particles. Silver ion‐containing dispersions demonstrate strong antibacterial properties, while the effect is diminished in the corresponding composite. Overall, the precipitation/emulsion polymerization of VME represents a promising pathway to stable sulfur‐rich polymer dispersions with the ability to coordinate metal ions or form reactive metal composites. [ABSTRACT FROM AUTHOR]

The thiol–yne coupling chemistry of diferrocenylacetylene (FcC≡CFc) 1, bearing two electron rich and redox-active ferrocenyl units (Fc = Fe(η5-C5H4)(η5-C5H5)) and an internal triple bond, has been investigated for the first time. In order to determine whether steric limitations might affect hydrothiolation, a model reaction using a functionalized monothiol was tested, namely 2-mercaptoethanol I. The thiol–diferrocenylacetylene reactions were initiated either thermally (in toluene with AIBN) or by UV light irradiation (in THF and in the presence of DMPA as the photoinitiator). The outcomes of these thiol–yne reactions showed a strong dependence on the initiation method used, with the thermally initiated one being the most efficient. These thiol–diferrocenylacetylene reactions mainly afforded the (Z)-stereoisomer of the newly obtained vinyl thioether sulfide FcCH＝C(Fc)S–(CH2)2OH (2), unlike the more common (E)-vinyl sulfides found in other additions to alkynes. The hydrothiolation of the internal –C≡C– bond in 1 was successfully extended to dithiol 2,2′-(ethylenedioxy)diethanethiol II, leading to the formation of the (ZZ)-isomer, with four ferrocenyl units, as the major product. According to the electrochemical studies, the new asymmetrical ferrocenyl–vinyl sulfides show iron–iron electronic and electrostatic interactions. Theoretical results for the (Z)-stereoisomer (2) suggest that adiabatic oxidation would lead to the loss of almost one electron on the ferrocenyl subunit closer to the thioether chain. Furthermore, the thiol–yne chemistry of the internal –C≡C– bond in diferrocenylacetylene has been compared to the external triple bond in ethynylferrocene, the theoretical results of which helped us to rationalize the very different reactivities observed in both metallocenes. [ABSTRACT FROM AUTHOR]

2-Mercaptoethanol (2-ME) is often used as an antioxidant to optimize culture systems for in vitro oocyte maturation in livestock. However, the relationship between 2-ME and autophagy has not yet been elucidated. In this study, we hypothesized that 2-ME can promote porcine oocyte maturation in vitro by maintaining autophagy homeostasis. To test this hypothesis, we explored the effects of 2-ME on the maturation of porcine oocytes exposed to an autophagy activator (rapamycin) or an autophagy inhibitor (3-methyladenine, i.e., 3-MA) in vitro. Rapamycin-induced autophagy over-activation significantly increased autophagy- and apoptosis-related gene expression, oxidative stress, apoptosis rates, abnormal mitochondrial redistribution, and significantly decreased oocyte first polar body extrusion (PBE) rates, spindle/chromosome integrity and developmental competence. 3-MA-mediated autophagy inhibition exerted similar effects on all these parameters except the expression of genes that promote autophagy and inhibit apoptosis. Importantly, 2-ME supplementation significantly attenuated the detrimental effects of rapamycin and 3-MA. Interestingly, we observed that 44 h of coincubation with rapamycin/3-MA and 2-ME restored autophagy homeostasis in vitro. In conclusion, our study confirmed that 2-ME promotes porcine oocyte maturation and embryo development in vitro by maintaining autophagy homeostasis and lays a foundation for further research on the underlying mechanism. • 2- mercaptoethanol can alleviate the damage of porcine oocyte maturation caused by inhibited autophagy. • 2- mercaptoethanol can alleviate the damage of porcine oocyte maturation caused by over-activated autophagy. • 2-mercaptoethanol can promote porcine oocyte maturation in vitro by maintaining autophagy homeostasis. [ABSTRACT FROM AUTHOR]

Cellulases are hydrolytic enzymes with wide scientific and industrial applications. We described a novel cellulase, CelC307, from the thermophilic indigenous Cohnella sp. A01. The 3-D structure of the CelC307 was predicted by comparative modeling. Docking of CelC307 with specific inhibitors and molecular dynamic (MD) simulation revealed that these ligands bound in a non-competitive manner. The CelC307 protein was purified and characterized after recombinant expression in Escherichia coli (E. coli) BL21. Using CMC 1% as the substrate, the thermodynamic values were determined as Km 0.46 mM, kcat 104.30 × 10–3 (S−1), and kcat/Km 226.73 (M−1 S−1). The CelC307 was optimally active at 40 °C and pH 7.0. The culture condition was optimized for improved CelC307 expression using Plackett–Burman and Box–Behnken design as follows: temperature 20 °C, pH 7.5, and inoculation concentration with an OD600 = 1. The endoglucanase activity was positively modulated in the presence of Na+, Li+, Ca2+, 2-mercaptoethanol (2-ME), and glycerol. The thermodynamic parameters calculated for CelC307 confirmed its inherent thermostability. The characterized CelC307 may be a suitable candidate for various biotechnological applications. [ABSTRACT FROM AUTHOR]

A new bioanalytical labeling system based on alloyed quantum dots' (QDs) photoluminescence quenching caused by an enzymatic reaction has been developed and tested for the first time. The catalytic role of the enzyme provides high sensitivity and the possibility of varying detecting time to improve assay sensitivity. Alloyed luminescent QDs were chosen in view of their small size (5–7 nm) and the high sensitivity of their optical properties to physicochemical interactions. Here, we described the synthesis of alloyed luminescent QDs and demonstrated the possibility of using them as a luminescent turn-off substrate for enzymatic assay. Synthesized alloyed QDs were found to be a sensitive turn-off substrate for glucose oxidase in homogeneous and heterogeneous assay models. CdZnSeS and CdZnSeS/ZnS QDs covered with dihydrolipoic acid and 2-mercaptoethanol were tested. A glucose oxidase limit of detection of 6.6 nM for the heterogenous high-throughput model assay was reached. [ABSTRACT FROM AUTHOR]

Hair waste from unhairing of bovine hide has high protein content and is also a current issue in tanneries as it causes high organic load to the wastewater. Given that, this study aims to recover keratin from bovine hair by investigating its hydrolysis from remaining solid hair from leather processing and unprocessed hair. For the keratin hydrolysis, 2-mercaptoethanol, Na2S, H2O2, NaOCl, NaOH, C2H4O2S, and HCOOH were tested. SDS-PAGE and the yield analysis of the extracted solution indicated that it was possible to recover proteins with molecular weights around 20 kDa, reusing this hair waste. In an oxidizing pathway (H2O2), 75% of the protein was extracted from the recovered hair powder, and a yield of up to 40% was achieved with Na2S in a reductive pathway. Overall, the results demonstrated good recovery of keratin from bovine hair, turning what was previously considered waste into an interesting source of this protein. [ABSTRACT FROM AUTHOR]

Treating red blood cells (RBCs) with dithiothreitol (DTT) is a wildly-recommended to overcome the interference of the daratumumab (DARA) with blood compatibility testing. Nevertheless, DTT can be hard to obtain in the clinical laboratory, while its use in routine practice may be time-consuming. In the following study, we explored the feasibility of using a commercial 2-mercaptoethanol (2-ME) working solution or the time-saving Polybrene method to mitigate DARA interference. Antibody screening and cross-matching were performed using 2-ME or DTT-based indirect antiglobulin tests (IATs) and Polybrene method (with human IgG anti-E same IATs titer as DARA as positive control) on 37 samples. Most clinically important blood group antigens on RBCs were detected after treatment with 2-ME or DTT. Treating RBCs with 2-ME eliminates the DARA interference with the antibody screening or cross-matching; yet, K antigen is denatured during treatment. DARA does not interfere with antibody screening and cross-matching via Polybrene method, while 2+ agglutinations of anti-E antibody with the same titer (IATs method) as DARA could be observed in the positive controls via this method. 2-ME-based IATs or Polybrene method could replace DTT-based IATs to mitigate DARA interference. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to synthesize several small molecules of the type 5-nitroimidazole-sulfanyl and evaluate biological properties against the main Leishmania species that cause cutaneous leishmaniasis in Venezuela. Final compounds 4–7 were generated through simple nucleophilic substitution of 1-(2-chloroethyl)-2-methyl-5-nitroimidazole 3 with 2-mercaptoethanol, 1-methyl-2-mercaptoethanol, and 2-thyolacetic acid derivative. Compound 8 was synthesized via a coupling reaction between 7 and (S)-Methyl 2-amino-4-methylpentanoate hydrochloride. The inhibitory concentrations of (3, 4, 7, 8) against Leishmania (L.) mexicana and (V.) braziliensis in promastigotes and experimentally infected macrophages were determined by in vitro activity assays. Compounds 7 and 8 shown high activity against both species of Leishmania and were selected for the in vivo evaluation. Animals were infected with promastigotes of the two species and divided into four groups of ten (10) animals and a control group. Intralesional injection way was used for the treatment. The parasitological diagnostic after treatment was obtained by PCR using species specific oligonucleotides. The two Leishmania species were susceptible to compounds 7 and 8 in vivo assays. The results indicated that both compounds reduce significantly (96%) the size of the lesion and cure 63% of the mice infected with L (L) mexicana or L (V) braziliensis as was determined by PCR. The results are indicating that both compounds may represent an alternative treatment for these two Leishmania species. [ABSTRACT FROM AUTHOR]

Modification of surface-enhanced Raman spectroscopy (SERS) substrates with thiol ligands is an emerging approach in enhancing the stability and sensitivity of metal substrates due to their good affinity with metals such as Au, Ag, and Cu. Thus, in the current study, 2-mercaptoethanol was used to modify the surface of silver-coated gold nanoparticles to develop a novel SERS substrate for the rapid assessment of fungicide residues in fruit samples. Results showed that the substrate could achieve the detection of ferbam and thiabendazole residues in apple puree with limits of detection of approximately 0.0042 and 0.0064 ppm, high coefficients of determination of 0.9946 and 0.9968, good recoveries ranging from 80 to 105 and 81 to 107% and relative standard deviations of 3.5–7.5 and 3.8–7.9 %, respectively. Therefore, the substrate developed could potentially be utilised to assess other toxic agrochemicals in future. [ABSTRACT FROM AUTHOR]

• Synthesis of zinc sulfide (ZnS) quantum dots (QDs) by simple precipitation method. • ZnS QDs were embedded in polyethersulfone (PES) composite nanofiltration membrane. • Antifouling properties and dye separation performance were improved. • FRR was improved greatly from 52.6% for bare PES to 87.9% for 2 wt.% QDs membrane. In this work, novel 2-mercaptoethanol capped zinc sulfide (ZnS) quantum dots (QDs) embedded polyethersulfone (PES) nanocomposite membranes were fabricated which revealed wh improved antifouling properties and dye separation performance. A simple water-based precipitation approach was used to obtain 2-mercaptoethanol capped ZnS QDs at ambient temperature. The resulting membranes were fully identified with SEM, AFM, ATR-FTIR analyses, and also underwent porosity and contact angle tests. The developed nanostructure membranes exhibited a remarkable fouling reduction in bovine serum albumin (BSA) protein filtration, as featured by a declined average surface roughness. The flux recovery ratio (FRR) was improved considerably from 52.6% for the neat PES to 87.9% for nanocomposite membrane by inserting 2 wt.% ZnS QDs. The contact angle of membrane decreased, while porosity size was enlarged by increase of the QDs loading. The prepared nanocomposite membranes showed an increased Reactive Red 195 rejection (from 91.3% to 96.1%) and an enhanced water and dye solution flux (from 121 to 163 L m−2 h−1) with respect to the bare PES membrane. Thus, the results proved the potential of the novel QDs/PES membrane for the dye separation applications. [ABSTRACT FROM AUTHOR]

CRM1 is a nuclear export receptor that has been intensively targeted over the last decade for the development of antitumor and antiviral drugs. Structural analysis of several inhibitor compounds bound to CRM1 revealed that their mechanism of action relies on the covalent modification of a critical cysteine residue (Cys528 in the human receptor) located in the nuclear export signal‐binding cleft. This study presents the crystal structure of human CRM1, covalently modified by 2‐mercaptoethanol on Cys528, in complex with RanGTP at 2.58 Å resolution. The results demonstrate that buffer components can interfere with the characterization of cysteine‐dependent inhibitor compounds. [ABSTRACT FROM AUTHOR]

The human THP-1 cell line is widely used as an in vitro model system for studying macrophage differentiation and function. Conventional culture conditions for these cells consist of ambient oxygen pressure (∼20% v/v) and medium supplemented with the thiol 2-mercaptoethanol (2-ME) and serum. In consideration of the redox activities of O₂ and 2-ME, and the extensive experimental evidence supporting a role for reactive oxygen species (ROS) in the differentiation and function of macrophages, we addressed the question of whether culturing THP-1 cells under a more physiologically relevant oxygen tension (5% O₂) in the absence of 2-ME and serum would alter THP-1 cell physiology. Comparisons of cultures maintained in 18% O₂versus 5% O₂ indicated that reducing oxygen tension had no effect on the proliferation of undifferentiated THP-1 cells. However, decreasing the oxygen tension to 5% O₂ significantly increased the rate of phorbol ester-induced differentiation of THP-1 cells into macrophage-like cells as well as the metabolic activity of both undifferentiated and PMA-differentiated THP-1 cells. Removal of both 2-ME and serum from the medium decreased the proliferation of undifferentiated THP-1 cells but increased metabolic activity and the rate of differentiation under either oxygen tension. In differentiated THP-1 cells, lowering the oxygen tension to 5% O₂ decreased phagocytic activity, the constitutive release of β-hexosaminidase and LPS-induced NF-κB activation but enhanced LPS-stimulated release of cytokines. Collectively, these data demonstrate that oxygen tension influences THP-1 cell differentiation and primary macrophage functions, and suggest that culturing these cells under tightly regulated oxygen tension in the absence of exogenous reducing agent and serum is likely to provide a physiologically relevant baseline from which to study the role of the local redox environment in regulating THP-1 cell physiology.

The synthesis and characterization of copper nanoparticles supported in carbon nanotubes is reported. Copper nanoparticles were obtained by the CLD (chemical liquid deposition) method consisting of reduced pressure evaporation of metals and subsequent low-temperature condensation (77K) of these vapors, with organic solvent vapors. From the reactions obtained by this method, copper colloids of concentrations 10-3 and 10-4 were synthesized in the organic solvents 2-propanol, 2-mercaptoethanol, 2-methoxyethanol and 2-ethoxyethanol. The support of copper nanoparticles in the carbon nanotubes was made by SMAD method with 24 hours under agitation and nitrogen atmosphere before collecting, obtaining copper nanoparticle solids supported in carbon nanotubes by evaporating the solvent either 2-mercaptoethanol or 2-ethoxyethanol. Colloidal and solid dispersions were characterized by diverse techniques, for colloidal dispersions UV-Vis spectrophotometry, electrophoretic mobility, electron transmission microscopy (TEM), electron diffraction and stability over time was used. Far-medium infrared spectroscopy (FT-IR) and thermogravimetry (TGA) were used for solids. These analyses show that Cu colloids are relatively stable in the solvents used, the most stable dispersion was synthesized in 2-mercaptoethanol and the less stable is synthesized in 2-methoxyethanol, which is demonstrated in UV spectra. By TEM, particle sizes were studied, between 5.2 and 17.2 nm. Electron diffraction confirms the presence of copper. Analysis of active solids shows in the case of FTIR that solvents are incorporated into copper particles, and in the case of thermograms it is shown that the solids synthesized in the solvent had greater thermal stability 2-mercaptoethanol. It was impossible to obtain electron diffraction from the copper nanoparticles visualized because they are incorporated in the multiwall nanotubes. [ABSTRACT FROM AUTHOR]

Genome sequence of Geobacillus thermopakistaniensis contains an open reading frame annotated as a type II L-asparaginase (ASNase Gt ). Critical structural analysis disclosed that ASNase Gt might be a type I L-asparaginase. In order to determine whether it is a type I or type II L-asparaginase, we have performed the structural-functional characterization of the recombinant protein as well as analyzed the localization of ASNase Gt in G. thermopakistaniensis. ASNase Gt exhibited optimal activity at 52 °C and pH 9.5. There was a > 3-fold increase in activity in the presence of β-mercaptoethanol. Apparent V max and K m values were 2735 U/mg and 0.35 mM, respectively. ASNase Gt displayed high thermostability with >80 % residual activity even after 6 h of incubation at 55 °C. Recombinant ASNase Gt existed in oligomeric form. Addition of β-mercaptoethanol lowered the degree of oligomerization and displayed that tetrameric form was the most active, with a specific activity of 4300 U/mg. Under physiological conditions, ASNase Gt displayed >50 % of the optimal activity. Localization studies in G. thermopakistaniensis revealed that ASNase Gt is a cytosolic protein. Structural and functional characterization, and localization in G. thermopakistaniensis displayed that ASNase Gt is not a type II but a type I L-asparaginase., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Metal colloids in 2-mercaptoethanol using nanoparticles (NPs) of iron (Fe), cobalt (Co), and nickel (Ni) were prepared by chemical liquid deposition method. Transmission electron microscopy, electron diffraction, UV-VIS spectroscopy, and scanning electron microscopy with electron dispersive X-ray spectroscopy characterized the resulting colloidal dispersions. The NPs exhibited sizes with ranges from 9.8 nm for Fe, 3.7 nm for Co, and 7.2 nm for Ni. The electron diffraction shows the presence of the metals in its elemental state Fe (0), Co (0), and Ni (0) and also some compounds FeO (OH), CoCo2S4, and NiNi2S4. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of ascorbic acid (Vitamin C) and 2-mercaptoethanol (ME) added to buffalo semen samples after thawing for 1 h and 2 h incubation. Ejaculates (n = 20) from eight Bulgarian Murrah buffaloes were frozen in pellets and straws at a final sperm concentration of 80 × 106 mL. We investigated the effect of supplementations on the motility, morphology of spermatozoa at 1 h and 2 h after thawing, sperm plasma membrane status and mitochondrial trans-membrane potential. The comparative CASA analysis of the motility and velocity parameters of spermatozoa showed significant differences in the progressive motility and in the VCL values in favour of control vs. samples with additives (p < 0.05). The molecular changes in PM phospholipid asymmetry were higher after thawing (p < 0.05). The semen treated with Vit C showed significant (p < 0.05) lower number of apoptotic spermatozoa (6CF+/Ann V Cy3+) in comparison with samples incubated with ME. The numbers of dead spermatozoa (6CF-/Ann V Cy3+) in samples with ME were significantly higher than other groups. The percentage of spermatozoa with well preserved and functioning mitochondria in control semen was higher (p < 0.05) than that in the experimental group with ME. The results obtained revealed that addition of Vit C (5 µmol/L) and ME (50 µmol/L) has no positive effect on post-thaw semen quality of buffalo sperm, because of the impaired integrity of PM and mitochondrial trans-membrane potential. [ABSTRACT FROM AUTHOR]

In this paper, three kinds of ZnS NPs capping different amount of mercaptoethanol (ME) were synthesized, and the effect of capping amount on ZnS NPs was studied, indicating that the capping amount of ME on ZnS surface decreases, while ZnS size increases as the decrease of added capping agent in synthesis process, and ZnS NP capping middle amount of ME (~27.7 wt%) shows a highest apparent refractive index (RI) value. ZnS NPs were composited into polymeric matrices by a simple "one-step" thermocuring method characterized by adding a small amount of functional monomer of glycidyl methacrylate (GMA) and solvent of N,N-dimethylformamide (DMF) The reaction mechanism, studied by 1H NMR spectra, indicates that the epoxy of GMA monomer can be easily opened and chemically grafted on ME-capped ZnS surface under the catalysis of DMF, and then copolymerized with other monomer. By the route, ZnS NPs can be composited into pure poly(N,N-dimethylacrylamide)-type (DMA-type), DMA-type copolymer, and DMA-free matrices to fabricate transparent films, and its RI value can be improved by either optimizing capping amount on ZnS surface or increasing ZnS content in the nanocomposites. The RI value of resulting dried nanocomposites can be improved to 1.764 by compositing 80 wt% ZnS capping middle amount of ME. [ABSTRACT FROM AUTHOR]

Biothiols play an important role in living cells and are associated with many diseases. Thus, it is necessary to develop a facile, cost-effective, and convenient analytical method for the detection of biothiols. Nanozymes are functional nanomaterials with enzymatic activities. Due to their unique advantages (e.g., low cost, high stability, and multifunctionality), nanozymes have been extensively used to construct sensing systems. Previous studies demonstrated colorimetric assays for biothiol detection because they could competitively inhibit the peroxidase-like activities of nanozymes. However, few studies were able to differentiate biothiols from each other. To address these challenges, herein, we first synthesized Au alloy nanozymes with better peroxidase-like activities than gold nanoparticles (AuNPs). Then, cross-reactive sensor arrays were constructed with three alloy nanozymes. Six typical biothiols (i.e., glutathione, cysteine, dithiothreitol, mercaptoacetic acid, mercaptoethanol, and mercaptosuccinic acid) were successfully detected and discriminated by the as-prepared nanozyme sensor arrays. Moreover, the practical application of the nanozyme sensor arrays was demonstrated by discriminating biothiols in serum successfully. [ABSTRACT FROM AUTHOR]

L-glutaminase is an enzyme that catalyse the conversion L-glutamine to glutamic acid and ammonia. The important application of the L-glutaminase is a chemotherapy agent. In this study a novel strain, Bacillus B12. that isolated from Diyala soil was explored for production of extracellular L-glutaminase. The enzyme has been purified 23.9-fold from cell-free extract with 45.4% recovery ( specific activity 76.6 U/mg protein). Enzyme has molecular weight of 199 kDa, and pH 8 and stable in pH range 6-9.5. Temperature optimum is 40 ⁰C and completely stable between 25-45 ⁰C. The kinetics studies revealed that the km and Vmax of purified L-glutaminase were estimated in 0.4mmol/L and 0.133mmol/min, respectively. The result showed that, the enzyme was active when incubated with 10 mM of Mn2+, Mg2+,Ca+2 and Na+. Whereas, K +, Co2+, and Ni2+ show no effect. However, Hg2+, Cu2+,Fe2+ and Zn2+ decreased L-glutaminase activity . The 10mM of DEAE, PMSF, and sodium azide did not show a clear effect against the enzyme activity. Higher decrease in enzyme activity was observed by using Cysteine and 2-Mercaptoethanol ( 30 and 25%, respectively). [ABSTRACT FROM AUTHOR]

In this abstract, we discuss the progress related to sulfonated carbon-based materials in various acid-catalyzed organic transformations which are then further utilized in medicinal field, laboratories and industries. A simple and novel methodology was employed to prepare carbon-based nanocatalyst, i.e. cellulose[2-(sulfooxy)ethyl]mercaptosulfonic acid as a solid acid catalyst. This nanocatalyst is recyclable and also exhibited very high activity. Novel carbon-based nanocatalyst, i.e. cellulose[2-(sulfooxy)ethyl]mercaptosulfonic acid[SEMSA] was successfully synthesized by reacting mercaptoethanol and chlorosulfonic acid, and the catalytic activity of the prepared catalysts was evaluated for the one-pot synthesis of gem-bisamides from various aldehydes and benzamide, hexahydroacridine-1,8-diones via three-component condensation of aromatic aldehyde, dimedone and ammonium acetate or aromatic amine and 1,8-dioxo-octahydroxanthenes using aldehyde and dimedone. Application of this new heterogeneous nanocatalyst system offered the advantages of high yields, short reaction times, eco-friendly nature and easy work-up procedure compared to the conventional methods of the synthesis, and confirmation of products synthesized has been done using studies like 1H NMR and 13C NMR. Among the various catalysts, this nanocatalyst, i.e. cellulose [2-(sulfooxy)ethyl]mercaptosulfonic acid[SEMSA], was found to be the most active and selective and could be recycled several times without significant loss of activity. Also, scanning electron microscopy and transmission electron microscopy of the catalyst have been performed to know the internal and external morphology, size, thermo-gravimetric analysis to study the thermal stability and Fourier transform infrared spectroscopy to study the modification pattern of the catalyst have been undertaken and presented in this work. Due to its simple and inexpensive solid support, i.e. cellulose and environmentally benign toluene, ethanol and acetonitrile as solvents in three different transformations which are less toxic, easily available and less expensive than other solvents. We reported here a novel route for the synthesis of gem-bisamides, hexahydroacridine-1,8-diones and 1,8-dioxo-octahydroxanthenes [ABSTRACT FROM AUTHOR]

The effect of intracellular adenosine triphosphate (ATP) on the "common gating" of the CLC-1 chloride channel has been studied by several laboratories with controversial results. Our previous study on the channel expressed in Xenopus oocytes using excised inside-out patch-clamp methods showed a robust effect of ATP in shifting the open probability curve of the common gate toward more depolarizing voltages (Tseng, P.Y., B. Bennetts, and T.Y. Chen. 2007. J. Gen. Physiol. 130:217-221). The results were consistent with those from studying the channel expressed in mammalian cells using whole cell recording methods (Bennetts, B., M.W. Parker, and B.A. Cromer. 2007. J. Biol. Chem. 282:32780-32791). However, a recent study using excised-patch recording methods for channels expressed in Xenopus oocytes reported that ATP had no direct effect on CLC-1 (Zifarelli, G., and M. Pusch. 2008. J. Gen. Physiol. 131:109-116). Here, we report that oxidation of CLC-1 may be the culprit underlying the controversy. When patches were excised from mammalian cells, the sensitivity to ATP was lost quickly--within 2-3 min. This loss of ATP sensitivity could be prevented or reversed by reducing agents. On the other hand, CLC-1 expressed in Xenopus oocytes lost the ATP sensitivity when patches were treated with oxidizing reagents. These results suggest a novel view in muscle physiology that the mechanisms controlling muscle fatigability may include the oxidation of CLC-1.

Vaccinia virus, the basis of the smallpox vaccine, is one of the largest viruses to replicate in humans. We have used in situ atomic force microscopy (AFM) to directly visualize fully hydrated, intact intracellular mature vaccinia virus (IMV) virions and chemical and enzymatic treatment products thereof. The latter included virion cores, core-enveloping coats, and core substructures. The isolated coats appeared to be composed of a highly cross-linked protein array. AFM imaging of core substructures indicated association of the linear viral DNA genome with a segmented protein sheath forming an extended approximately 16-nm-diameter filament with helical surface topography; enclosure of this filament within a 30- to 40-nm-diameter tubule which also shows helical topography; and enclosure of the folded, condensed 30- to 40-nm-diameter tubule within the core by a wall covered with peg-like projections. Proteins observed attached to the 30- to 40-nm-diameter tubules may mediate folding and/or compaction of the tubules and/or represent vestiges of the core wall and/or pegs. An accessory "satellite domain" was observed protruding from the intact core. This corresponded in size to isolated 70- to 100-nm-diameter particles that were imaged independently and might represent detached accessory domains. AFM imaging of intact virions indicated that IMV underwent a reversible shrinkage upon dehydration (as much as 2.2- to 2.5-fold in the height dimension), accompanied by topological and topographical changes, including protrusion of the satellite domain. As shown here, the chemical and enzymatic dissection of large, asymmetrical virus particles in combination with in situ AFM provides an informative complement to other structure determination techniques.

Background: Brucellosis is a systemic infection caused by gram-negative coccobacilli and facultative intracellular bacteria of the genus brucella. Brucellosis is a bacterial disease common to humans and livestock. Infection with Brucella spp. continues to pose a human health risk globally despite strides in eradicating the disease from domestic animals. The humoral and cellular immunity plays an important role in brucellosis. The effect of phagocytosis and cellular immunity has been demonstrated in brucellosis. The effect of cupping as a therapeutic method on bacterial diseases has been demonstrated. By considering this fact that cupping is an effective method on host immune system functions and has potential effect to regulate the inflammatory reactions. Methods: This experimental study was carried out on 48 rats in 6 groups (48 rats were divided into 6 groups) during the first 6 months from January 2015 to July 2016 in the laboratory of microbiology and animal of Hamedan University of Medical Sciences. The rats were infected through the injection of Brucella melitensis with plenty 5×105 (cfu/ml) of bacteria. After a week, in order to approve the accuracy of the infection in the studied rats inoculated with coombos Brucella melitensis, Wright test, 2-Mercaptoethanol test and Coombs' Wright test were used. The rats were then treated with cupping method in their sacral area. IFN-γ was measured using enzyme-linked immunosorbent assay. And the study of tissues using hematoxylin and eosin (H&E) Staining. Results: The results of this study showed that cupping leads to an increase in the mean serum level of interferon-gamma. The histopathological study of liver tissue showed that the radial arrangement was not observed in the infected group with brucellosis and the cells were acidophilus. While, the radial arrangement was observed in treated rats with cupping, but it was not complete. The number of enlarged sinusoids were reduced. But, cell infiltration was observed. Conclusion: This study showed that cupping can increase serum level of IFN-γ, and thus help to the clearance of disease and improvement of injury in the brucellosis animals lab.

Various control strategies are available for building fluorogenic probes to visualize biological events in terms of a fluorescence change. Here, we performed the time-dependent density functional theory (TD-DFT) computational analysis of the twisted intramolecular charge transfer (TICT) process in rhodamine dyes. On the basis of the results, we designed and synthesized a series of rhodamine dyes and established a fluorescence quenching strategy that we call steric repulsion-induced TICT (sr-TICT), in which the fluorescence quenching process is greatly accelerated by simple intramolecular twisting. As proof of concept of this design strategy, we used it to develop a fluorogenic probe, 2-Me PeER (pentyloxyethylrhodamine), for the N -dealkylation activity of CYP3A4. We applied 2-Me PeER for CYP3A4 activity-based fluorescence-activated cell sorting (FACS), providing access to homogeneous, highly functional human-induced pluripotent stem cell (hiPSC)-derived hepatocytes and intestinal epithelial cells. Our results suggest that sr-TICT represents a general fluorescence control method for fluorogenic probes.

This work describes the reactivity and properties of fluorinated derivatives ( F-PD and F-PDO ) of plasmodione ( PD ) and its metabolite, the plasmodione oxide ( PDO ). Introduction of a fluorine atom on the 2-methyl group markedly alters the redox properties of the 1,4-naphthoquinone electrophore, making the compound highly oxidizing and particularly photoreactive. A fruitful set of analytical methods (electrochemistry, absorption and emission spectrophotometry, and HRMS-ESI) have been used to highlight the products resulting from UV photoirradiation in the absence or presence of selected nucleophiles. With F-PDO and in the absence of nucleophile, photoreduction generates a highly reactive ortho -quinone methide ( o -QM) capable of leading to the formation of a homodimer. In the presence of thiol nucleophiles such as β-mercaptoethanol, which was used as a model, o -QMs are continuously regenerated in sequential photoredox reactions generating mono- or disulfanylation products as well as various unreported sulfanyl products. Besides, these photoreduced adducts derived from F-PDO are characterized by a bright yellowish emission due to an excited-state intramolecular proton transfer (ESIPT) process between the dihydronapthoquinone and benzoyl units. In order to evidence the possibility of an intramolecular coupling of the o -QM intermediate, a synthetic route to the corresponding anthrones is described. Tautomerization of the targeted anthrones occurs and affords highly fluorescent stable hydroxyl-anthraquinones. Although probable to explain the intense visible fluorescence emission also observed in tobacco BY-2 cells used as a cellular model, these coupling products have never been observed during the photochemical reactions performed in this study. Our data suggest that the observed ESIPT-induced fluorescence most likely corresponds to the generation of alkylated products through reduction species, as demonstrated with the β-mercaptoethanol model. In conclusion, F-PDO thus acts as a novel (pro)-fluorescent probe for monitoring redox processes and protein alkylation in living cells.

Methanogenic and methanotrophic archaea play important roles in the global carbon cycle by interconverting CO 2 and methane. To conserve energy from these metabolic pathways that happen close to the thermodynamic equilibrium, specific electron carriers have evolved to balance the redox potentials between key steps. Reduced ferredoxins required to activate CO 2 are provided by energetical coupling to the reduction of the high-potential heterodisulfide (HDS) of coenzyme M (2-mercaptoethanesulfonate) and coenzyme B (7-mercaptoheptanoylthreonine phosphate). While the standard redox potential of this important HDS has been determined previously to be -143 mV (Tietze et al. 2003 DOI: 10.1002/cbic.200390053), we have measured thiol disulfide exchange kinetics and reassessed this value by equilibrating thiol-disulfide mixtures of coenzyme M, coenzyme B, and mercaptoethanol. We determined the redox potential of the HDS of coenzyme M and coenzyme B to be -16.4±1.7 mV relative to the reference thiol mercaptoethanol (E 0 '=-264 mV). The resulting E 0 ' values are -281 mV for the HDS, -271 mV for the homodisulfide of coenzyme M, and -270 mV for the homodisulfide of coenzyme B. We discuss the importance of these updated values for the physiology of methanogenic and methanotrophic archaea and their implications in terms of energy conservation., (© 2023 The Authors. ChemBioChem published by Wiley-VCH GmbH.)

Previously, we have investigated three C-terminal esterified endomorphin-2 (EM-2) analogs EM-2-Me, EM-2-Et and EM-2-Bu with methyl, ethyl and tert-butyl ester modifications, respectively. These analogs produced significant antinociception in acute pain at the spinal and supraspinal levels, with reduced tolerance and gastrointestinal side effects. The present study was undertaken to determine the analgesic effects and opioid mechanisms of these three analogs in the formalin pain test. Our results demonstrated that intracerebroventricular (i.c.v.) administration of 0.67-20 nmol EM-2 analogs EM-2-Me, EM-2-Et and EM-2-Bu produced dose-dependent antinociceptive effects in both phase Ⅰ and phase Ⅱ of formalin pain. EM-2-Me and EM-2-Bu displayed more potent antinociception than morphine. Especially, EM-2-Bu exhibited the highest antinociception in phase Ⅱ of formalin pain, with the ED 50 value being 2.1 nmol. Naloxone (80 nmol, i.c.v.) completely antagonized the antinociceptive effects of EM-2-Me, EM-2-Et and EM-2-Bu (20 nmol, i.c.v.) in both phase I and phase Ⅱ of formalin pain, suggesting a central opioid mechanism. Nevertheless, the antinociception induced by EM-2-Me might be involved in the release of dynorphin A, which subsequently acted on κ- opioid receptor. EM-2-Bu produced the antinociception probably by the direct activation of both μ- and δ-opioid receptors. EM-2-Me, EM-2-Et and EM-2-Bu also produced significant analgesic effects after peripheral administration, and the central opioid receptors were involved. Furthermore, EM-2-Bu had no influence on the locomotor activity after i.c.v. injection. The present investigation demonstrated that C-terminal esterified modifications of EM-2 will be beneficial for developing novel therapeutics in formalin pain., Competing Interests: Declarations of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Reports on the vitrification of somatic cells are scarce. Here, we show that Leydig cells (murine cell line TM3) could be successfully vitrified by both open vitrification [plastic straw (PS) and plastic vials (PV)] and closed ultravitrification [microdrop (MD) and solid surface vitrification (SSV)], after protocol optimization. However, open ultravitrification resulted in better post-warming viability than closed systems of vitrification with highest success obtained in modified SSV (84.8 ± 1.86%; p < 0.05). Leydig cells vitrified-warmed by modified SSV also showed superior (p < 0.05) cell growth, mitochondrial activity and cytoplasmic esterase enzyme activity, than MD, PS and PV, respectively. It was also observed that vitrified-warmed cells had higher level of ROS activity than non-vitrified control cells (41.6 ± 4.0 vs. 16.7 ± 1.0; p < 0.05). Treatment of cells with glutathione (GSH) or 2-mercaptoethanol (2-ME) (0, 10, 50, 100 μM) significantly (p < 0.05) reduced the ROS activity but had no significant (p > 0.05) effect on post-warm viability. Nevertheless, antioxidant-treated cells had improved mitochondrial activity, cytoplasmic esterase activity and cell growth during in vitro culture (p < 0.05). In conclusion, our results suggest that modified SSV offers a viable method for vitrifying single cell suspension of Leydig cells. To the best of our knowledge, this is the first report on cryopreservation of Leydig cells by vitrification. [ABSTRACT FROM AUTHOR]

Highlights • Tl AP was highly expressed in P. pastoris with a specific activity of 1795.4 U/mg. • It was acido-mesophilic, showing optimal activities at pH 3.0 and 55 °C. • It retained highly stable (>70% activity) at pH 3.0–6.0 and at 45 °C and below. • It was highly resistant against most metal ions and chemical reagents. • It showed ability to decrease juice turbidity and disintegrate haze-forming proteins. Abstract Aspartic proteases are promising fining agents used in the production of fruit juices. In this study, a novel aspartic protease gene (Tlap) was identified in Talaromyces leycettanus JCM12802 and heterologously expressed in Pichia pastoris. Using casein as the substrate, purified recombinant Tl AP showed optimal activities at pH 3.0 and 55 °C with a specific activity of 1795.4 ± 62.8 U/mg, and remained stable over a pH range of 3.0–6.0 and at temperatures of 45 °C and below. Moreover, the enzyme was highly resistant to most metal ions and chemical reagents except for Fe3+ and β- mercaptoethanol. When added to apple, orange, grape and kiwi fruit juice, it showed excellent proteolytic activity against haze-forming proteins, decreasing the turbidity by up to 49.9 nephelometry turbidity units (NTU). These favorable enzymatic properties make Tl AP attractive for potential use in the juice industry. [ABSTRACT FROM AUTHOR]

A novel thermostable carboxylesterase (Est5250) of thermoalkaliphilic bacterium Bacillus thermocloaceae was heterologously expressed in Escherichia coli and its biochemical properties were investigated. Est5250 showed optimum esterase activity at 60 °C and pH 8.0. The enzyme was highly thermostable at 60 °C, interestingly, the thermostability was enhanced in the presence of Ca2+, retaining more than 60% of its original activity after 12 h of pre-incubation. Est5250 was active in the presence of 1% (v/v) of organic solvents and 0.1% (v/v) of non-ionic detergents. The enzyme activity was significantly enhanced up to 167% and 159% in the presence of 2-mercaptoethanol and dithiothreitol, respectively. Est5250 showed high substrate specificity for short-chain p-nitrophenyl-esters. Kinetic constants, Km and kcat, for p-nitrophenyl-acetate were 185.8 μM and 186.6 s−1, respectively. Est5250 showed outstanding thermostability and tolerance to various organic solvents under thermoalkaliphilic conditions, suggesting that it would be a highly suitable biocatalyst for various biotechnological applications. Abbreviations:B. thermocloaceae sp.: Bacillus thermocloaceae; E. coli: Escherichia coli; NP: nitrophenyl; DMSO: dimethyl sulfoxide; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; DMF: dimethyl formamide; EGTA: ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid; CTAB: cetrimonium bromide; PMSF: phenylmethylsulfonyl fluoride; DEPC: diethyl pyrocarbonate; 2-ME: 2-mercaptoethanol; DTT: dithiothreitol Enhancement of thermostability of Est5250 in the presence of Ca2+. [ABSTRACT FROM AUTHOR]

This research project introduced a novel transition metal‐free C−C coupling reaction that is believed to be a new revolution in Suzuki type reactions. Carbon‐carbon bond formation can be promoted by a mixture of 2‐mercaptoethanol/KOH/DMSO without the aid of any transition metals. It has been suggested that this reaction proceeds through radical species, hence the electron transfer route is suggested for the operation during the oxidation of 2‐mercaptoethanol in DMSO. [ABSTRACT FROM AUTHOR]

Abstract Three replicate seawater samples were collected on three different days, filtered immediately and preserved with one of two guanidinium thiocyanate-based preservatives (DNAzol™ or RNA Lysis Buffer™ plus β-mercaptoethanol (RLA+)) and were kept frozen while being shipped to a lab. In parallel, a carboy of seawater was collected on each of the three days and maintained at ambient temperature while being shipped to a lab. Upon receipt the samples were filtered and treated in the same manner as for immediate preservation. Significantly more DNA was obtained from samples immediately preserved with DNAzol than the corresponding shipped samples for 2 of the 3 days. More DNA was extracted from DNAzol preserved samples but more RNA was obtained from RLA+ preserved samples. A protocol was designed to extract both DNA and RNA from split samples preserved with RLA+ and cDNA was synthesized from the RNA. Three high-throughput 16S rRNA gene libraries were constructed, one from DNA preserved with DNAzol, one from DNA preserved with RLA+ and one from cDNA (RLA+ preserved). Greater alpha diversity was found for libraries constructed from immediately preserved vs. shipped samples for both preservation types, with immediate preservation with DNAzol obtaining the highest level of diversity. Libraries constructed from immediately preserved (RLA+) DNA had greater alpha diversity than libraries constructed from shipped preserved (RLA+) DNA or cDNA. Unifrac measures of beta diversity showed clearer separation of sample types and a greater % variance explained for weighted than for unweighted principal coordinate analysis (PCoA) plots, indicating sample types varied more in their relative abundance of taxa than the presence/absence of particular taxa. We recommend immediate preservation of seawater samples, with DNAzol as the preferred preservative if quantification via qPCR will be performed or the highest alpha diversity is desired but preservation with RLA+ if RNA will be extracted. Highlights • The microbial community of unpreserved seawater loses diversity within a few days. • Chemical preservatives are recommended when on-site extraction is not possible. • The specific chemical preservative recommended is different for DNA than for RNA. [ABSTRACT FROM AUTHOR]

Graphical abstract The synthetic route of the CPVA/MoS 2 -OH nanocatalyst. Highlights • A novel photocatalyst comprised MoS 2 nanosheets and CPVA had been successfully synthesized. • MoS 2 nanosheets were modified to MoS 2 -OH by 2-Mercaptoethanol. • CPVA/MoS 2 -OH nanocatalyst showed efficient photocatalytic properties for Cr(VI). Abstract In this work, a novel efficient photocatalyst comprising molybdenum disulfide (MoS 2) nanosheets and conjugated polyvinyl alcohol (CPVA) has been successfully synthesized. To effectively coat the conjugated polyvinyl alcohol on the surface of molybdenum disulfide, molybdenum disulfide nanosheets were first modified to hydroxylated molybdenum disulfide (MoS 2 -OH) using 2-mercaptoethanol. The morphologies, chemical compositions, crystal phases and optical properties of the obtained CPVA/MoS 2 -OH were characterized. The results showed the CPVA was successfully coating onto MoS 2 nanosheets, and improved the light absorption, electron transport ability and charge transfer ability of MoS 2. The obtained CPVA/MoS 2 -OH presented a significant enhancement of photoactivity towards chromium (VI) reduction. The CPVA/MoS 2 -OH-1wt% with the filling ratio of CPVA: MoS 2 -OH at 1:100 exhibited the best photocatalytic activity, in which the chromium (VI) reduction efficiency was 96% (Simulated sunlight, 105 min). The corresponding rate constant was approximately 2.27 times higher than that of neat MoS 2. The improvement in catalytic performance might be due to the enhanced light absorption and electron transport capacity resulted from the photocurrent response tests and free radical capture experiments. In addition, the effect of the dosage of photocatalyst, Cr(VI) solution concentrations and pH of Cr(VI) aqueous solution on the catalyst performance for CPVA/MoS 2 -OH-1wt% were investigated. [ABSTRACT FROM AUTHOR]

A sensitive chiral high performance liquid chromatography (HPLC) method for the determination of aliphatic primary amino alcohol isomers with o‐phthaldialdehyde/mercaptoethanol precolumn derivatization has been developed and validated. Seven chiral columns were tested in a reversed phase mode. Excellent enantioseparation with the resolution more than 2.0 was achieved on Chiralcel OJ‐3R. The effect of various chromatographic conditions including column temperature, acetonitrile content in the mobile phase, buffer pH, buffer concentration, and buffer type in the mobile phase on the retention and the selectivity was investigated. The final mobile phase consisted of binary mixture of 20mM ammonium formate solution with acetonitrile (75:25; v/v). The analyses were performed at mobile phase flow rate of 1.0 mL/min and the column temperature of 40°C. The fluorescence detection was performed at excitation wavelength of 345 nm and emission wavelength of 450 nm. The developed method was fully validated in terms of linearity, sensitivity, accuracy, precision, intermediate precision, and selectivity according to International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines using internal normalization procedure. The proposed chiral method was proved to be highly sensitive, simple, and rapid and was successfully applied to the determination of D‐Valinol content in commercially available samples of L‐Valinol. [ABSTRACT FROM AUTHOR]