Search

Carbonic anhydrases (CA, EC 4.2.1.1) catalyze the hydration of carbon dioxide and take part in many essential physiological processes. In humans, 15 CAs are characterized, including the only secreted isoenzyme CA VI. CA VI has been linked to specific processes in the mouth, namely bitter taste perception, dental caries, and maintenance of enamel pellicle, and implicated in several immunity-related phenomena. However, little is known of the mechanisms of the above. In this study, we characterized human CA VI purified from saliva and milk with biophysical methods and measured their enzyme activities and acetazolamide inhibition. Size-exclusion chromatography showed peaks of salivary and milk CA VI corresponding to hexameric state or larger at pH 7.5. At pH 5.0 the hexamer peaks dominated. SDS- PAGE of milk CA VI protein treated with a bifunctional crosslinker further confirmed that a majority of CA VI is oligomers of similar sizes in solution. Mass spectrometry experiments confirmed that both of the two putative N-glycosylation sites, Asn67 and Asn256, are heterogeneously glycosylated. The attached glycans in milk CA VI were di- and triantennary complex-type glycans, carrying both a core fucose and 1 to 2 additional fucose units, whereas the glycans in salivary CA VI were smaller, seemingly degraded forms of core fucosylated complex- or hybrid-type glycans. Mass spectrometry also verified the predicted signal peptide cleavage site and the terminal residue, Gln 18, being in pyroglutamate form. Thorough characterization of CA VI paves way to better understanding of the biological function of the protein.

Dissolved organic matter (DOM) degradation in freshwater rivers and streams plays a major role in the global carbon cycle. However, little is known about how the source and composition of riverine DOM contribute to the production of greenhouse gases, especially in high-latitude areas with a large proportion of carbon-rich peatlands. Here, we conducted for the first time the combination of molecular-level characterization of terrestrially derived DOM and the potential carbon dioxide (CO2) production measurements in pristine subarctic rivers of Finnish Lapland. 21-day incubation studies were conducted with water samples taken from two rivers differing in DOM content during spring and fall 2018. The changes in the DOM concentration and molecular composition, as well as the CO2 production, were measured. The DOM molecular characterization was carried out using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Our results demonstrate efficient mineralization of dissolved organic carbon (DOC) into CO2 in mineral soil associated clearwater river during the incubation, while significantly lower CO2 production per DOC was observed in the brown-water river surrounded by peatlands. The limited degradability in the brown-water river was caused by a large number of terrestrial and aromatic compounds (i.e., highly unsaturated and phenolic compounds, condensed aromatics, and polyphenolics) from surrounding peatlands. In the clearwater river, the percentage of formulas assigned to aliphatics decreased over the incubation, indicating microbial utilization of biolabile DOM. This study highlights the importance of energy-rich, biolabile molecular compounds and the contribution of clearwater systems in the DOM degradation dynamics of subarctic catchments.

Funding Information: Financial support from the Academy of Finland (decision 317903, I.O.K.; decision 340584, T.E. and A.J.K.; Flagship Programme, Photonics Research and Innovation PREIN, decision 320166) and computational resources from the Finnish IT Center for Science (CSC) are gratefully acknowledged. Publisher Copyright: © 2022 The Authors. Published by American Chemical Society. The phosphonium-decorated phenanthro-imidazolyl pyridine ligand, LP +Br, readily reacts with zinc(II) and cadmium(II) bromides to give inorganic-organic zero-dimensional compounds [ LP +ZnBr2]2[ZnBr4] ( 1 ) and [( LP +)2Cd2Br4][CdBr4] ( 2 ), respectively, upon crystallization. These salts are moderately fluorescent in the solid state under ambient conditions (λem = 458 nm, φem = 0.11 for 1 ; λem = 460 nm, φem = 0.13 for 2 ). Their emission results from spin-allowed electronic transitions localized on the organic component with the negligible effect of [MBr4]2- and MBr2 units. Contrary to ionic species 1 and 2 , lead(II) bromide affords a neutral and water-stable complex [( LP +)2Pb3Br8] ( 3 ), showing weak room-temperature phosphorescence arising from spin-orbit coupling due to the heavy atom effect. The emission, which is substantially enhanced for the amorphous sample of 3 (λem = 575 nm, φem = 0.06), is assigned to the intraligand triplet excited state, which is a rare phenomenon among Pb(II) molecular materials.

Along with the evidence and analyses expounded on in this book, this chapter provides conclusions and suggestions concerning policy implications. These are based on a perspective that calls attention to the need for a holistic approach to look at the nexus of forests, the bioeconomy and climate change. Moreover, it is emphasised that, given the different uses of forests and the scarcity of forest resources, it makes sense to try to find ways to maximise synergies and minimise trade-offs between the different usages of forests. The forest-based sector contributes to climate-change mitigation via three channels––forests are a carbon sink, forest-based products can substitute for fossil-based products, and these products can store carbon for up to centuries. However, achieving these mitigation potentials in the future depends on forests being made resilient to the changing climate. Therefore, mitigation and adapting forests to climate change are married, both needing to be advanced simultaneously. Globally and in the EU, around 80–90% of the CO2 emissions originate from the use of coal, oil and natural gas. Consequently, the core issue in the fight against climate change is the phasing out of fossil-based products. Reaching this goal will not be possible without substituting also forest-based bioproducts for the purposes we are using oil, coal and gas for today. In the EU, this implies paying more attention to the need to develop new innovations in the forest bioeconomy, improve the resource efficiency and circularity of the bioproducts already available, and monitor the environmental sustainability of the bioeconomy.

Collagen prolyl 4-hydroxylases (C-P4H) are α

The tree bark represents an abundant but currently underutilized forest biomass side stream. In this work, temperature-programmed slow pyrolysis with fractional condensation was used for thermochemical conversion of the bark obtained from three short rotation tree species, aspen, goat willow, and rowan. Heating was performed in three stages, drying (135 °C), torrefaction (275 °C), and pyrolysis (350 °C), and the resulting vapors were condensed at 120, 70, and 5 °C, producing nine liquid fractions. An additional fraction was collected in the pyrolysis stage at 0 °C. The obtained liquid fractions were characterized in terms of their yields and bulk chemistry (i.e., CHNOS content, water content, pH, and total acid number) as well as their molecular level chemistry by high-resolution mass spectrometry. The highest liquid yields were obtained for the fractions condensed at 70 °C. The water content varied considerably, being the highest for the drying fractions (>96%) and the lowest for the pyrolysis fractions obtained at 120 °C (0.1-2%). Considerable compositional differences were observed between the liquid fractions. While the drying fractions contained mostly some dissolved phenolics, the torrefaction fractions contained more sugaric compounds. In contrast, the pyrolysis fractions were enriched lipids (e.g., suberinic fatty acids and their derivatives) and alicyclic/aromatic hydrocarbons. These fractions could be further refined into different platforms and/or specialty chemicals. Thus, slow pyrolysis with fractional condensation offers a potential route for the valorization of tree bark residues from forest industry.

International audience; Seven cloud water samples were collected from May to October 2018 at the Puy de Dôme station (PUY) in France and analyzed by positive-ion atmospheric pressure photoionization [(+)APPI] Fourier transform ion cyclotron resonance mass spectrometry. The assigned formulas (ranging from 3,865 to 6,380) were attributed using the multidimensional stoichiometric constraint classification of Rivas-Ubach et al. (2018, https://doi.org.10.1021/acs.analchem.8b00529) to six main categories (RUCs): LipidC, ProteinC, Amino-sugarC, CarbohydrateC, NucleotideC, and OxyaromaticC. Back trajectories were calculated by the computing atmospheric trajectory tool (CAT) model to obtain information on the air mass history. Partial least square regressions were performed using chemical data, CAT back-trajectory calculations and FT-ICR MS data to analyze the environmental variability of the organic sample composition. ProteinC is correlated with the continental surface for air masses transported within the boundary layer, and Amino-sugarC is strongly correlated with acetate, NO3- and NH4+, suggesting Anthropogenic sources for amino sugars and proteins. LipidC is correlated with the sea surface for air masses transported within the free troposphere, confirming the long-range transport of marine biogenic sources. Concerning Oxy-aromaticC, given the correlations with oxidants and pollutants, as well as anti-correlations with local influence, we proposed a mechanism of oxidation from remote anthropogenic sources.

The state of the world’s managed forests is determined by the societal demands for wood resources and other ecosystem services. The forest-based sector is experiencing a number of structural changes, which makes the task of looking ahead important, but challenging. One of the main trends in the forest-based industries is diversification. On one hand, this refers to the emergence of new factors influencing the demand for forest-based products, which leads to substitution between forest-based products and alternative products. On the other hand, it refers to new market opportunities for forest-based industries in, for example, the construction, textiles, packaging, biochemicals and biofuels markets. As the importance of some of the traditional forest-based industries, such as communication papers, is declining, and new opportunities are simultaneously emerging, the sector will not necessarily be dominated by single sectors in the long term. However, research illuminating the possible impacts of the expected structural changes of the forest-based sector remains scarce. The uncertainties in the future outlook of the forest-based sector also imply great uncertainties in the demand for roundwood globally, and by extension, the extent of trade-offs between different ecosystem services and land uses.

The photocatalytic degradation of carbamazepine (CBZ) in ultra-pure water was investigated by using neodymium (Nd)-doped antimony trioxide (Sb2O3)/titanium dioxide (TiO2) photocatalyst under the UVC irradiations of 254 nm wavelength. The hydrothermal method was used for the fabrication catalyst samples with different ratios of Nd (0%–2%) dopant, and characterised by X-ray diffraction pattern (XRD) to investigate the crystallinity. Scanning electron microscopy (SEM) provided the surface morphologies, Bruanuer-Emmer-Teller (BET) analysis gave the textural properties, and UV–Vis diffuse reflectance absorption spectroscopy (DRS) was used for the investigation of the optical properties of synthesized catalysts. TEM images of Sb2O3 showed a nanorod-like structure while, in the Nd-doped Sb2O3/TiO2, a small dot-like structure was observed along with the nanorods. The surface area and band gap of 1% Nd-doped Sb2O3/TiO2 were found to be 9.56 m2 g−1 and 3.0 eV respectively. It was observed that the CBZ cannot be degraded in the absence of catalyst under UV light, while photocatalyst 1% Nd-doped Sb2O3/TiO2 at 0.5 g/L of catalyst dose showed the best photocatalytic activity towards CBZ degradation. The main degradation products were identified with high-resolution mass spectrometry. Moreover, the degradation of CBZ followed pseudo first-order kinetics and the rate constant was 0.017 min−1. Quenching tests by the addition of methanol from 100 to 500 mM were carried out to determine the major reactive oxygen species, which showed that OH radicals was involved in the CBZ degradation. Active species-trapping experiments revealed that ∙O2− is also responsible for the degradation of CBZ.

Phosphine ligands, containing chromophore substituents –π-spacer–NPh2 (π-spacer = biphenyl, L1; naphthalene-ethynylphenyl, L2; and ethynyl-(phenylethynyl)anthracene, L3), were used to generate the corresponding gold(I) alkynyl complexes Au1–Au3 (alkynyl = ethynylphenyl-2,2′-bipyridine, epbpy). These compounds demonstrate intense fluorescence, which originates from the bipolar donor–π-acceptor systems of coordinated phosphines with negligible contribution from the epbpy fragment. Due to the charge transfer characteristic of the excited state, Au1–Au3 reveal significant emission solvatochromism (particularly discernible for Au2, 428 nm in cyclohexane → 580 nm in acetonitrile). The bipyridine moiety of Au1–Au3 was utilized for binding these metalloligands to the {Eu(tta)3} red emitter (tta = 3-thenoyltrifluoroacetonate) to give a family of novel dyads Au1Eu–Au3Eu. Incomplete energy transfer from L1–L3 to lanthanide ions, which are primarily sensitized by diketonate ligands, leads to dual luminescence. Analogous to the parent complexes Au1–Au3, the fluorescence component of the dyads is highly sensitive to the solvent polarity that provides great opportunities for color tuning, including white light generation.

Thyroid hormones are important regulatory hormones, acting on nearly every cell in the body. The two main thyroid hormones are l-thyroxine (tetraiodo-l-thyronine, T4) and 3,3′,5-triiodo-l-thyronine (T3), which are produced in the thyroid gland and secreted into the blood stream. Other important thyroid hormone metabolites are 3,3′-diiodo-l-thyronine (T2) and l-thyronine (T0), which may show increased levels in circulation due to dietary iodine deficiency or other medical disorders. Owing to their central role in cellular functions, sensitive and specific detection methods for thyroid hormones are needed. In this work, native mass spectrometry (MS) was used to quantitate thyroid hormone binding to the anti-T4 antibody Fab fragment. First, the binding affinity for T2 was determined via direct ligand titration experiments. Then, the affinities for the other ligands were determined by competition experiments using T2 as the "low-affinity" reference ligand. The highest affinity was measured for T3, followed by T4, T2, and T0 (Kd = 29, 3.4, and 260 nM and 130 μM, respectively). Thus, it is evident that the number and positions of the iodine substituents within the thyronine rings are important for the ligand binding affinity of anti-T4 Fab. Surprisingly, structurally related tetrahalogen bisphenols were also able to bind to anti-T4 Fab with nanomolar affinities.

The release of pharmaceuticals into aquatic environments is a serious concern due to the persistence and potential health and environmental risks of these substances. Surface and ground waters are polluted with a variety of pharmaceuticals due to insufficient water purification processes in wastewater treatment plants. Here, we report a simple procedure for the production of composite materials consisting of zero-valent iron embedded in few-layer graphene, Fe/graphene, through induction annealing at 900 °C. Zero-valent iron was observed as magnetic 1 µm-sized crystals embedded in the graphene matrix appearing in the α- and γ-forms. This Fe/graphene composite was applied as an adsorbent for the removal of tetracycline (a pharmaceutical) from water. The Fe/graphene showed high tetracycline removal efficiency (422 mg/g) under optimized conditions. Furthermore, the Fe/graphene possessed self-regenerating features prolonging its lifetime and total removal capacity up to 660 mg/g, thus making it a potential material for removing tetracycline from water.

Groundwater : : journal of the Association of Ground-Water Scientists and Engineers, a division of the National Ground Water Association (2021). doi:10.1111/gwat.13087, Published by Wiley-Blackwell, Oxford [u.a.]

Chemical fingerprinting of phenolic compounds present in Finnish berry wines was performed using a direct-infusion Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The main aim of this study was to compare the phenolics profiles of wines produced from natural and/or cultivated berries and to demonstrate the feasibility of FT-ICR MS for a direct chemical analysis of the wine samples without chromatographic separation. First, phenolic compounds were recovered from the wine samples by solid-phase extraction (SPE), and the total phenolic content (TPC) was then determined by a Folin-Ciocalteau assay. The TPC of the original berry wines varied from 421 to 2108 mg/L, while the TPC of the extracts was 157-1525 mg/L. Over fifty phenolic compounds were tentatively identified from the wine samples by FT-ICR MS, whose concentrations highly varied depending on the types of berries used in the winemaking process.

Fibronectin type-II (FnII) family proteins are the major proteins in many mammalian species including bull, horse and pig. In the present study, a major FnII protein has been identified and isolated from donkey (Equus hemionus) seminal plasma, which we refer to as D onkey S eminal P lasma protein-1 (DSP-1). The amino acid sequence determined by mass spectrometry and computational modeling studies revealed that DSP-1 is homologous to other mammalian seminal plasma proteins, including bovine PDC-109 (also known as BSP-A1/A2) and equine HSP-1/2. High-resolution LC-MS analysis indicated that the protein is heterogeneously glycosylated and also contains multiple acetylations, occurring in the attached glycans. Structural and thermal stability studies on DSP-1 employing CD spectroscopy and differential scanning calorimetry showed that the protein unfolds at ~43 °C and binding to phosphorylcholine (PrC) – the head group moiety of choline phospholipids – increases its thermal stability. Intrinsic fluorescence titrations revealed that DSP-1 recognizes lyso-phosphatidylcholine with over 100-fold higher affinity than PrC. Further, interaction of DSP-1 with erythrocytes, a model cell membrane, revealed that DSP-1 binding is mediated by a specific interaction with choline phospholipids and results in membrane perturbation, suggesting that binding of this protein to sperm plasma membrane could be physiologically significant.

This article reports on the macronization of self-supported 3D CNT foam inter-connected by heteroatom-enriched porous shells derived from renewable baking ingredients via mild pyrolysis. The synthesized hybrids enabled disintegrating peroxymonosulfate (PMS) into reactive oxidants (sulfate radicals, hydroxyl radicals, and singlet oxygen) for the degradation of atenolol, iopamidol, metformin, trimethoprim, and phenol in water. Hierarchically structured nitrogen- and oxygen-doping significantly enhanced adsorptive and catalytic performance whereas the magnetic 3D framework promoted mass transport, multicycle use and induced synergetic effects via the Me-Nx-C interfaces. The samples were highly efficient for degradative removal of model pollutants at low catalyst and PMS dose. The catalyst loading, PMS dose, contact time, and temperature positively influenced the removal potency while pH and water matrix governed the rates differently. Spin trapping, oxidant quenching and solvent isotope effect study coupled with liquid chromatography and Fourier transform ion cyclotron resonance mass spectrometry analysis suggested the footprints of transformation products via a dual-mode (radical and non-radical) activation of PMS. This durable, magnetic carbofoam might be a promising catalyst for the oxidative abatement of pharmaceutical micropollutants from contaminated waters.

The SCP2 (sterol carrier protein 2)-thiolase (type-1) functions in the vertebrate peroxisomal, bile acid synthesis pathway, converting 24-keto-THC-CoA and CoA into choloyl-CoA and propionyl-CoA. This conversion concerns the β-oxidation chain shortening of the steroid fatty acyl-moiety of 24-keto-THC-CoA. This class of dimeric thiolases has previously been poorly characterized. High-resolution crystal structures of the zebrafish SCP2-thiolase (type-1) now reveal an open catalytic site, shaped by residues of both subunits. The structure of its non-dimerized monomeric form has also been captured in the obtained crystals. Four loops at the dimer interface adopt very different conformations in the monomeric form. These loops also shape the active site and their structural changes explain why a competent active site is not present in the monomeric form. Native mass spectrometry studies confirm that the zebrafish SCP2-thiolase (type-1) as well as its human homolog are weak transient dimers in solution. The crystallographic binding studies reveal the mode of binding of CoA and octanoyl-CoA in the active site, highlighting the conserved geometry of the nucleophilic cysteine, the catalytic acid/base cysteine and the two oxyanion holes. The dimer interface of SCP2-thiolase (type-1) is equally extensive as in other thiolase dimers; however, it is more polar than any of the corresponding interfaces, which correlates with the notion that the enzyme forms a weak transient dimer. The structure comparison of the monomeric and dimeric forms suggests functional relevance of this property. These comparisons provide also insights into the structural rearrangements that occur when the folded inactive monomers assemble into the mature dimer.

This study identifies new wood-based products with considerable potential and attractive markets, including textiles, liquid biofuels, platform chemicals, plastics, and packaging. We apply a mixed-...

Tuberculosis (Tb), caused by Mycobacterium tuberculosis (Mtb), is responsible for more than a million deaths annually. In the latent phase of infection, Mtb uses lipids as the source of carbon and energy for its survival. The lipid molecules are transported across the cell wall via multiple transport systems. One such set of widely present and less-studied transporters is the Mammalian-cell-entry (Mce) complexes. Here, we report the properties of the substrate-binding proteins (SBPs; MceA-F) of the Mce1 and Mce4 complexes from Mtb which are responsible for the import of mycolic acid/fatty acids, and cholesterol respectively. MceA-F are composed of four domains namely, transmembrane, MCE, helical and tail domains. Our studies show that MceA-F are predominantly monomeric when purified individually and do not form homohexamers unlike the reported homologs (MlaD, PqiB and LetB) from other prokaryotes. The crystal structure of MCE domain of Mtb Mce4A (MtMce4A39-140) determined at 2.9 Å shows the formation of an unexpected domain-swapped dimer in the crystals. Further, the purification and small-angle X-ray scattering (SAXS) analysis on MtMce1A, MtMce4A and their domains suggest that the helical domain requires hydrophobic interactions with the detergent molecules for its stability. Combining all the experimental data, we propose a heterohexameric arrangement of MtMceA-F SBPs, where the soluble MCE domain of the SBPs would remain in the periplasm with the helical domain extending to the lipid layer forming a hollow channel for the transport of lipids across the membranes. The tail domain would reach the cell surface assisting in lipid recognition and binding.

Inorganic and organic pollutants present a hazard to surface and groundwater resources. Peroxymonosulfate (PMS, HSO5−) has received increasing attention for in situ chemical oxidation (ISCO) capable of remediating contaminated sites. Considering that saline waters occur widely in natural environments, it is desirable to evaluate the effect of Cl− on the PMS oxidation of organic compounds. In this study, 2,4-dichlorophenol (2,4-DCP) was used as a model pollutant. At a PMS concentration of 2.0 mM, Cl− concentration of 50 mM, and solution pH of 7.0, 2,4-DCP was completely degraded by PMS in the presence of Cl− (PMS/Cl− system), while PMS alone exhibited almost no reactivity with 2,4-DCP. The degradation of 2,4-DCP was optimized at a solution pH of 8.4 and high concentrations of PMS and Cl−. Quenching experiments and degradation pathway analyses indicated that HClO was responsible for 2,4-DCP oxidation, and HClO was mainly generated by the interaction of Cl− with HSO5−, rather than SO52−. Consequently, the transformation from HSO5− to HClO appeared under a solution pH of 10.0 and was favored in an acidic solution. Given the ambient pH and Cl− concentrations of saline waters, a considerable amount of HClO may be produced by the interaction of PMS with Cl− in the oxidant delivery stage of ISCO processes. Interestingly, H2O2 and peroxydisulfate did not exhibit reactions similar to those of PMS. This research indicated that caution must be exercised when choosing an oxidant for ISCO processes in saline waters.

Journal of cell science 133(19), jcs239202 (1-15) - (2020). doi:10.1242/jcs.239202, Integrin activation and clustering by talin are early steps of cell adhesion. Membrane-bound talin head domain and kindlin bind to the �� integrin cytoplasmic tail, cooperating to activate the heterodimeric integrin, and the talin head domain induces integrin clustering in the presence of Mn$^{2+}$. Here we show that kindlin-1 can replace Mn2+ to mediate ��3 integrin clustering induced by the talin head, but not that induced by the F2���F3 fragment of talin. Integrin clustering mediated by kindlin-1 and the talin head was lost upon deletion of the flexible loop within the talin head F1 subdomain. Further mutagenesis identified hydrophobic and acidic motifs in the F1 loop responsible for ��3 integrin clustering. Modeling, computational and cysteine crosslinking studies showed direct and catalytic interactions of the acidic F1 loop motif with the juxtamembrane domains of ��- and ��3-integrins, in order to activate the ��3 integrin heterodimer, further detailing the mechanism by which the talin���kindlin complex activates and clusters integrins. Moreover, the F1 loop interaction with the ��3 integrin tail required the newly identified compact FERM fold of the talin head, which positions the F1 loop next to the inner membrane clasp of the talin-bound integrin heterodimer., Published by Company of Biologists Limited, Cambridge

Biomass pyrolysis liquids (bio-oils) unavoidably require catalytic hydrodeoxygenation (HDO) for their upgrading and stabilization for commercial usage. The complex composition of bio-oil constrains...