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The development of changes in the activity of creatinkinase, aldolase and succinatdehydrogenase in brain cells under 30-day long stress induced by isolation and violated diurnal cycle has been studied. It was shown that these enzymes heterogeneously responded to 30-day long stress. Particular sensitivity was recorded in the case of succinatedehydrogenase, which showed the decline of activityin various sections of the brain by 60-80% on average. Unlike succinatedehydrogenase, aldolase activity increased on the 10th day of stress and then declined. Similar results were observed in relationto phosphokinase activity.

Sulfoquinovose (SQ) is a key component of plant sulfolipids (sulfoquinovosyl diacylglycerols) and a major environmental reservoir of biological sulfur. Breakdown of SQ is achieved by bacteria through the pathways of sulfoglycolysis. The sulfoglycolytic sulfofructose transaldolase (sulfo-SFT) pathway is used by gut-resident firmicutes and soil saprophytes. After isomerization of SQ to sulfofructose (SF), the namesake enzyme catalyzes the transaldol reaction of SF transferring dihydroxyacetone to 3C/4C acceptors to give sulfolactaldehyde and fructose-6-phosphate or sedoheptulose-7-phosphate. We report the 3D cryo-EM structure of SF transaldolase from Bacillus megaterium in apo and ligand bound forms, revealing a decameric structure formed from two pentameric rings of the protomer. We demonstrate a covalent "Schiff base" intermediate formed by reaction of SF with Lys89 within a conserved Asp-Lys-Glu catalytic triad and defined by an Arg-Trp-Arg sulfonate recognition triad. The structural characterization of the signature enzyme of the sulfo-SFT pathway provides key insights into molecular recognition of the sulfonate group of sulfosugars. [Display omitted] • Sulfoquinovose (SQ) accounts for up to half of the global biosulfur cycle • The sulfoglycolytic sulfofructose transaldolase pathway enables catabolism of SQ • 2.1-Å cryo-EM structure of the sulfofructose transaldolase Schiff base intermediate • The catalytic mechanism involves an Asp-Lys-Glu triad Snow et al. present the high-resolution cryo-EM analysis of sulfofructose transaldolase, a key component of the sulfoglycolytic pathway. The analysis unveils the Schiff-based intermediate complex with sulfofructose and highlights the key residues involved in sulfonate recognition and specificity. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is an aggressive tumor, whose development is considered to be modulated by certain long non‑coding RNAs (lncRNAs). Therefore, the aim of the present study was to investigate the regulatory mechanism of lncRNA NONHSAG028908.3 on CRC. Data from The Cancer Genome Atlas (TCGA) database revealed that NONHSAG028908.3 was increased in CRC tissues compared with normal tissues (P<0.001). The results of reverse transcription‑quantitative PCR indicated that NONHSAG028908.3 was upregulated in four types of CRC cells compared with that in NCM460, a normal colorectal cell line. MTT, BrdU, and flow cytometric assays were applied to evaluate CRC cell growth. The migratory and invasive abilities of CRC cells were detected using wound healing and Transwell assays. Silencing of NONHSAG028908.3 inhibited proliferation, migration, and invasion of CRC cells. A dual‑luciferase reporter assay demonstrated that NONHSAG028908.3 served as a sponge to combine with microRNA (miR)‑34a‑5p. MiR‑34a‑5p suppressed the aggressiveness of CRC cells. The effects induced by NONHSAG028908.3 knockdown were partly reversed by inhibition of miR‑34a‑5p. Furthermore, miR‑34a‑5p, a target of NONHSAG028908.3, modulated aldolase, fructose‑bisphosphate A (ALDOA) expression in a negative feedback manner. Suppression of NONHSAG028908.3 notably decreased ALDOA expression, which was rescued via silencing of miR‑34a‑5p. Moreover, suppression of ALDOA revealed the inhibitory action on CRC cell growth and migration. In summary, the data of the present study indicate that NONHSAG028908.3 may positively regulate ALDOA via sponging miR‑34a‑5p, thereby promoting malignant activities in CRC.

Purpose: To present a case of nonparaneoplastic autoimmune retinopathy in association with myasthenia gravis in a young woman, and to report the effect of plasmapheresis as well as passage of antiretinal antibodies through the placenta. Methods: Case report. Results: A 31-year-old woman presented with a history of myasthenia gravis and rapidly progressive vision loss at the age of 23. Funduscopic appearance and fluorescein angiographic findings on presentation were consistent with an autoimmune retinopathy. Paraneoplastic etiology was ruled out, and antiretinal antibody testing revealed positivity for autoantibodies against GAPDH, aldolase, enolase, arrestin, as well as unnamed 48-kDa and 60-kDa proteins. ARA Western Blot and immunohistochemistry profiles were unchanged by either plasmapheresis therapy or passage of serum through the maternal placenta. However, the patient's 6-month and 8-year-old daughters appeared unaffected. Conclusion: This is the first report of nonparaneoplastic autoimmune retinopathy associated with myasthenia gravis, although a strong history of autoimmune disorders is a known risk factor. Our patient's antiretinal antibody panel was unaffected immediately after plasmapheresis treatment. Antibodies to GAPDH and unnamed 38-kDa and 86-kDa proteins were able to pass through the placenta into the fetal circulation, although their effect on the growing fetus is not clear. [ABSTRACT FROM AUTHOR]

Background Fish is one of the most allergenic foods. While clinical cross-reactivity among different fishes is a widely accepted feature of fish allergy, associations with other food allergies are not well understood. This study aims at analyzing the relevance of clinical cross-reactivity between fish and chicken meat in patients with allergy to chicken meat without sensitization to hen's eggs. Methods Patients with food allergy to fish and chicken meat ( n = 29) or chicken meat only ( n = 7) were recruited. IgE-reactive chicken proteins were identified (Edman, MS analysis) and quantified ( ELISA). Allergens were used in IgE ELISA and skin testing. Results Chicken parvalbumin and two new allergens, aldolase and enolase, were identified at 12, 40, and 50 kDa, respectively. They were recognized by sIgE of 61%, 75%, and 83% of all patient sera which were in the majority of the cases positive for the fish homologues as well. Fish and chicken meat allergens were highly cross-reactive while high inhibition rates with fish or chicken allergens correlated with the patients' primary sensitization to fish or chicken. In cooked or roasted foods, enolase and aldolase were detectable in chicken breast while parvalbumin was detectable in chicken legs and wings. Conclusions Fish and chicken meat are cross-reactive foods; both fish-allergic and chicken meat-allergic patients might be at risk of developing a food allergy to chicken meat or to fish, respectively. This clinical phenomenon is proposed to be termed 'fish-chicken syndrome' with cross-reactive allergens involved being parvalbumins, enolases, and aldolases. [ABSTRACT FROM AUTHOR]

The interaction between some proteins and immune globulin has been confirmed as an important source of matrix interference with the immunoassay of fishery products, but detailed biochemical properties of these proteins have not been indicated. Two interference-inducing proteins (42 and 36 kD) in flounder were isolated, characterized, and identified. Their influences on the immunoassay of norfloxacin were confirmed by western blotting and enzyme-linked immunosorbent assay. The pI value and pH stability of the two proteins were also investigated. Using LC-MS/MS, the two proteins were identified as fructose-bisphosphate aldolase, and such results were partly verified by the aldolase activity of the 42 and 36 kD isolates. Considering the prevalence of these proteins (as multi-functional aldolase of muscles) in foods, these results would help to further understand the matrix effects in various immunoassays as well as the development of effective techniques to improve the efficiency of immunoassays. [ABSTRACT FROM AUTHOR]

A new strategy to fabricate electrochemical biosensor is reported based on the linkage of enzyme substrate, thereby an electrochemical method to detect aldolase activity is established using pectin-thionine complex (PTC) as recognization element and signal probe. The linkage effect of fructose-1,6-bisphosphate (FBP), the substrate of aldolase, can be achieved via its strong binding to magnetic nanoparticles (MNPs)/aminophenylboronic acid (APBA) and the formation of phosphoramidate bond derived from its reaction with p -phenylenediamine (PDA) on the surface of electrode. Aldolase can reversibly catalyze the substrates into the products which have no binding capacity with MNPs/APBA, resulting in the exposure of the corresponding binding sites and its subsequent recognization on signal probe. Meanwhile, signal amplification can be accomplished by using the firstly prepared PTC which can bind with MNPs/APBA, and accuracy can be strengthened through magnetic separation. With good precision and accuracy, the established sensor may be extended to other proteins with reversible catalyzed ability. [ABSTRACT FROM AUTHOR]

The activity of enzymes of glycolysis has been studied in erythrocytes from type-II diabetic patients in comparison with control. RBC lysate was the source of enzymes. In the diabetics the hexokinase (HK) activity increased 50 % while activities of phosphoglucoisomerase (PGI), phosphofructokinase (PFK) and aldolase (ALD) decreased by 37, 75 and 64 % respectively but were still several folds higher than that of HK. Hence, it is possible that in the diabetic erythrocytes the process of glycolysis could proceed in an unimpaired or in fact may be augmented due to increased levels of G6P. The lactate dehydrogenase (LDH) activity was comparatively high in both the groups; the diabetic group showed 85 % increase. In control group the HK, PFK and ALD activities showed strong positive correlation with blood sugar level while PGI activity did not show any correlation. In the diabetic group only PFK activity showed positive correlation. The LDH activity only in the control group showed positive correlation with marginal increase with increasing concentrations of glucose. [ABSTRACT FROM AUTHOR]

The trans-o-hydroxybenzylidene pyruvate aldolase-catalysed reactions between fluoropyruvate and many (hetero)aromatic aldehydes yield aldol adducts without subsequent dehydration. Treatment of the reaction products with hydrogen peroxide yields the corresponding syn-configured α-fluoro β-hydroxy carboxylic acids which have >98 % ee. The overall chemoenzymatic approach, in which fluoropyruvate serves as a fluoroacetate equivalent, may be exploited in the synthesis of polar building blocks and fragments with potential value in drug discovery. [ABSTRACT FROM AUTHOR]

Primary hyperoxaluria type-3 is characterized by increased oxalate production caused by mutations in the HOGA1 gene encoding 4-hydroxy-2-oxoglutarate aldolase (HOGA1). How the most commonly occurring mutations affect the cellular fates of the expressed HOGA1 mutants is still unknown. We show that two prevalent recombinant HOGA1 mutants are thermally unstable with evidence for chaperone-mediated degradation when expressed in E. coli. In stably transformed HEK-293 cells, protein expression of the Glu315 deletion mutant only becomes detectable during incubation with a 26S proteasome inhibitor. These findings suggest that failure of chaperone-assisted folding leads to targeted cellular degradation and an absolute absence of HOGA1 function. [ABSTRACT FROM AUTHOR]

The excretion of cytoplasmic proteins (ECP) is a long-known phenomenon in bacteria and eukaryotes. So far, it was not possible to associate either a signal peptide-dependent or a signal peptide-independent pathway to ECP. Nevertheless 25 % of the proteins found in Staphylococcus aureus supernatants were cytoplasmic proteins. Because the excreted proteins do not possess a common motive, the most widespread opinion is that ECP is due to cell lysis. This explanation seems to be too easy since several indications imply that there exists a yet unknown mechanism for ECP. Certainly, the up-regulation of autolysins as well as decreased peptidoglycan cross-linking increased ECP. However, in recent years, several evidences arose that cell lysis is not the only reason for ECP. It seems that ECP is a part of the normal cell cycle of S. aureus as it turned out that ECP with several model proteins occurs mainly during cell growth. It has common features as proteins secreted via the Sec translocon and finally the excretion site is the cross wall of dividing cells. [ABSTRACT FROM AUTHOR]

The impact of malaria on global health has continually prompted the need to develop effective diagnostic strategies. In malaria endemic regions, routine diagnosis is hampered by technical and infrastructural challenges to laboratories. These laboratories lack standard facilities, expertise or diagnostic supplies; thus, therapy is administered based on clinical or self-diagnosis. There is the need for accurate diagnosis of malaria due to the continuous increase in the cost of medication, and the emergence and spread of drug resistant strains. However, the widely utilized Giemsa-stained microscopy and immunochromatographic tests for malaria are liable to several drawbacks, including inadequate sensitivity and false-positive outcomes. Alternative methods that offer improvements in performance are either expensive, have longer turnaround time or require a level of expertise that makes them unsuitable for point-of-care (POC) applications. These gaps necessitate exploration of more efficient detection techniques with the potential of POC applications, especially in resource-limited settings. This minireview discusses some of the recent trends and new approaches that are seeking to improve the clinical diagnosis of malaria.

Fish is a common trigger of severe, food-allergic reactions. Only a limited number of proteins induce specific IgE-mediated immune reactions. The major fish allergens are the parvalbumins. They are members of the calcium-binding EF-hand protein family characterized by a conserved protein structure. They represent highly cross-reactive allergens for patients with specific IgE to conserved epitopes. These patients might experience clinical reactions with various fish species. On the other hand, some individuals have IgE antibodies directed against unique, species-specific parvalbumin epitopes, and these patients show clinical symptoms only with certain fish species. Furthermore, different parvalbumin isoforms and isoallergens are present in the same fish and might display variable allergenicity. This was shown for salmon homologs, where only a single parvalbumin (beta-1) isoform was identified as allergen in specific patients. In addition to the parvalbumins, several other fish proteins, enolases, aldolases and fish gelatin, seem to be important allergens.New clinical and molecular insights advanced the knowledge and understanding of fish allergy in the last years. These findings will be useful for the advancement of the IgE-based diagnosis but also for the management of fish allergies consisting of advice and treatment of fish-allergic patients.

Equine gastric ulcer syndrome (EGUS) is a highly prevalent disease that affects horses worldwide. Within EGUS, two different forms have been described: equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD). The associated clinical signs cause detrimental activity performance, reducing the quality of life of animals. Saliva can contain biomarkers for EGUS that could be potentially used as a complementary tool for diagnosis. The objective of this work was to evaluate the measurements of calprotectin (CALP) and aldolase in the saliva of horses as potential biomarkers of EGUS. For this purpose, automated assays for the quantification of these two proteins were analytically validated and applied for detecting EGUS in a total of 131 horses divided into 5 groups: healthy horses, ESGD, EGGD, combined ESGD and EGGD, and horses with other intestinal pathologies. The assays showed good precision and accuracy in analytical validation, and they were able to discriminate between horses with EGUS and healthy horses, especially in the case of CALP, although they did not show significant differences between horses with EGUS and horses with other diseases. In conclusion, salivary CALP and aldolase can be determined in the saliva of horses and further studies are warranted to elucidate the potential of these analytes as biomarkers in EGUS.

The preferred carbon source of Staphylococcus aureus and many other pathogens is glucose, and its consumption is critical during infection. However, glucose utilization increases the cellular demand for manganese, a nutrient sequestered by the host as a defense against invading pathogens. Therefore, bacteria must balance glucose metabolism with the increasing demand that metal-dependent processes, such as glycolysis, impose upon the cell. A critical regulator that enables S. aureus to resist nutritional immunity is the ArlRS two-component system. This work revealed that ArlRS regulates the expression of FdaB, a metal-independent fructose 1,6-bisphosphate aldolase. Further investigation revealed that when S. aureus is metal-starved by the host, FdaB functionally replaces the metal-dependent isozyme FbaA, thereby allowing S. aureus to resist host-imposed metal starvation in culture. Although metal-dependent aldolases are canonically zinc-dependent, this work uncovered that FbaA requires manganese for activity and that FdaB protects S. aureus from manganese starvation. Both FbaA and FdaB contribute to the ability of S. aureus to cause invasive disease in wild-type mice. However, the virulence defect of a strain lacking FdaB was reversed in calprotectin-deficient mice, which have defects in manganese sequestration, indicating that this isozyme contributes to the ability of this pathogen to overcome manganese limitation during infection. Cumulatively, these observations suggest that the expression of the metal-independent aldolase FdaB allows S. aureus to alleviate the increased demand for manganese that glucose consumption imposes, and highlights the cofactor flexibility of even established metalloenzyme families. IMPORTANCE Staphylococcus aureus and other pathogens consume glucose during infection. Glucose utilization increases the demand for transition metals, such as manganese, a nutrient that the host limits as a defense mechanism against invading pathogens. Therefore, pathogenic bacteria must balance glucose and manganese requirements during infection. The two-component system ArlRS is an important regulator that allows S. aureus to adapt to both glucose and manganese starvation. Among the genes regulated by ArlRS is the metal-independent fructose 1,6-bisphosphate aldolase fdaB , which functionally substitutes for the metal-dependent isoenzyme FbaA and enables S. aureus to survive host-imposed manganese starvation. Unexpectedly, and differing from most characterized metal-dependent aldolases, FbaA requires manganese for activity. Cumulatively, these findings reveal a new mechanism for overcoming nutritional immunity as well as the cofactor plasticity of even well-characterized metalloenzyme families.

Michael addition reactions are highly useful in organic synthesis and are commonly accomplished using organocatalysts. However, the corresponding biocatalytic Michael additions are rare, typically lack synthetically useful substrate scope, and suffer from low stereoselectivity. Herein we report a biocatalytic nitro-Michael addition, catalyzed by NahE, that proceeds with low catalyst loading at room temperature in moderate to excellent enantioselectivity and high yields. A series of β-nitrostyrenes reacted with pyruvate in the presence of NahE to give, after oxidative decarboxylation, β-aryl-γ-nitrobutyric acids in up to 99 % yield without need for chromatography, providing a simple preparative-scale route to chiral GABA analogues. This reaction represents the first example of an aldolase displaying promiscuous Michaelase activity and opens the use of nitroalkenes in place of aldehydes as substrates for aldolases., (© 2022 Wiley-VCH GmbH.)

This study describes the design a novel microbioreactor for the biocatalysed asymmetric synthesis of polyhydroxylated compounds. The bioreactor was elaborated by a hierarchical assembly of a recombinant fructose-6-phosphate aldolase (FSA wt ), layered double hydroxides (LDH) nanoplatelets and polysaccharide beads. Various polysaccharides were tested to encapsulate FSA wt and pre-immobilised FSA wt in LDH (FSA wt @Mg 2 Al-LDH). ι-Carrageenan appears as the most suitable candidate to prepare biohybrid beads. The retained activities in ι-carrageenan beads were measured for both free FSA wt and immobilised FSA wt revealing a 3 fold higher activity in favour of the pre-immobilised FSA. This result was probably due to a positive interaction between the negatively charged polysaccharide and the positively charged LDH layers. The catalytic activity, the recyclability and the storage of the beads were studied in addition to the leakage of FSA wt activity from beads. Nanostructuration of both FSA wt /ι-carr and FSA wt @Mg 2 Al-LDH/ι-carr was investigated by structural and textural characterization techniques. [ABSTRACT FROM AUTHOR]

As proteins evolve, amino acid positions key to protein structure or function are subject to mutational constraints. These positions can be detected by analyzing sequence families for amino acid conservation or for coevolution between pairs of positions. Coevolutionary scores are usually rank-ordered and thresholded to reveal the top pairwise scores, but they also can be treated as weighted networks. Here, we used network analyses to bypass a major complication of coevolution studies: For a given sequence alignment, alternative algorithms usually identify different, top pairwise scores. We reconciled results from five commonly-used, mathematically divergent algorithms (ELSC, McBASC, OMES, SCA, and ZNMI), using the LacI/GalR and 1,6-bisphosphate aldolase protein families as models. Calculations used unthresholded coevolution scores from which column-specific properties such as sequence entropy and random noise were subtracted; "central" positions were identified by calculating various network centrality scores. When compared among algorithms, network centrality methods, particularly eigenvector centrality, showed markedly better agreement than comparisons of the top pairwise scores. Positions with large centrality scores occurred at key structural locations and/or were functionally sensitive to mutations. Further, the top central positions often differed from those with top pairwise coevolution scores: instead of a few strong scores, central positions often had multiple, moderate scores. We conclude that eigenvector centrality calculations reveal a robust evolutionary pattern of constraints--detectable by divergent algorithms--that occur at key protein locations. Finally, we discuss the fact that multiple patterns coexist in evolutionary data that, together, give rise to emergent protein functions. [ABSTRACT FROM AUTHOR]

l -Rhamnulose-1-phosphate aldolase from a thermophilic source ( Thermotoga maritima MSB8) (RhaD T.mari ) was heterologously overexpressed in Escherichia coli and the stereoselectivity of this enzyme with or without Nus tag was investigated. We also applied this enzyme to the synthesis of rare sugars d -psicose, d -sorbose, l -tagatose and l -fructose using our one-pot four-enzyme system. To the best of our knowledge, this is the first use of RhaD from a thermophilic source for rare sugar synthesis and the temperature tolerance of this enzyme paves the path for large scale fermentation. [ABSTRACT FROM AUTHOR]

Neuraminidase is a virulence factor in many viruses and pathogenic bacteria. There are few reports of the detection of neuraminidase in the Aeromonas genus, but they do not include biochemical studies on the enzyme. In this work the neuraminidase production of Aeromonas sp. 40/02 strain and some properties of the enzyme were investigated for the first time. Neuraminidase was found in the supernatant, as well as in the cytosolic and membrane fractions of disrupted cells. It was demonstrated that the enzyme production is induced by a number of compounds structurally related to sialic acid. New data on the presence of extracellular and intracellular N-acylneuraminate lyase were obtained, suggesting a nutritional role of sialometabolism in this strain. For the first time, Aeromonas neuraminidase was isolated and partially purified by ion-exchange chromatography. Different purification profiles were registered depending on the growth media. The preparations containing neuraminidase activity were analyzed by native PAGE, and one of them was associated with an active protein band with a molecular weight of about 130 kDa. Our results suggest the presence of neuraminidase isoforms in Aeromonas sp. 40/02. [ABSTRACT FROM AUTHOR]

Eosinophilic fasciitis (EF) is a rare localized fibrosing disorder of the fascia whose diagnosis is often suspected based on clinical findings and laboratory values. These lab abnormalities can be transient in early disease and may not always be present. We have reviewed a case series of patients to assess the utility of the various laboratory abnormalities in diagnosing EF. We performed a retrospective review of EF patients seen at Georgetown University Hospital in the Division of Rheumatology during 2009 and 2013. This review included 15 adult patients with EF with a mean age at diagnosis of 45 years (range 18 to 77 years). The majority of patients 13/15 had classic skin thickening documented on all four extremities Only eight patients had peripheral eosinophilia ranging between 8 and 38 %. In these patients, the peripheral eosinophilia was an early but transient finding. Inflammatory markers including the erythrocyte sedimentation rate (ESR) was elevated in 5/14 and C-reactive Protein (CRP) was elevated in 7/11. At disease presentation, only one of eleven patients checked had an elevated creatine phosphokinase (CPK). Aldolase levels were available for 12 of the 15 patients, and they were increased in 11 out of 12 patients. We have found that in this case series, aldolase was more likely to be abnormal than peripheral eosinophilia, hypergammaglobulinemia, and ESR particularly after starting treatment. Aldolase should be measured in all patients suspected of having EF, and may also play a useful role in following disease activity. [ABSTRACT FROM AUTHOR]

Aldolase plays an important role in glycolysis and gluconeogenesis to produce D-fructose-1,6-bisphosphate (D-FBP) from dihydroxyacetone phosphate (DHP) and D-glyceraldehyde-3-phosphate (D-GAP). This reaction is stereoselective and retains the D-GAP 2R configuration and yields D-FBP (with the configuration: 3S, 4S, 5R). The 3- and 4-position carbons are the newly formed chiral carbons because the 5-position carbon of D-FBP comes from the 2-position of D-GAP. Although four diastereomeric products, ( 3S, 4R, 5R), ( 3R, 4R, 5R), ( 3R, 4S, 5R), ( 3S, 4S, 5R), are expected in the nonenzymatic reaction, only the ( 3S, 4S, 5R) diastereomer (D-FBP) is obtained. Therefore, the chirality in the 3- and 4-positions is induced by the chirality of the enzyme composed of L-amino acid residues. D-Glucose-6-phosphate (D-G6P), which is generated from D-FBP in the gluconeogenesis pathway, produces D-ribose-5-phosphate (D-R5P) in the pentose phosphate pathway. D-R5P is converted to PRPP (5-phosphoribosyl-α-pyrophosphate), which is used for the de novo synthesis of nucleotides. Ribonucleic acid (RNA) uses the nucleotides as building blocks. The configurations of the 4R-carbon and of the 3S-carbon are retained. The stereochemical structure of RNA is based on 3S as well as 4R (D). The consideration above suggests that aldolase is a key enzyme that determines the 3S configuration in D-R5P. It is thus a chirality intersection between amino acids and sugars, because the sugar chirality is determined by the chiral environment of an L-amino acid protein, aldolase, to produce D-FBP. [ABSTRACT FROM AUTHOR]

We synthesized four 5-nitrothiazole ( 1 – 4 ) and four 6-nitrobenzothiazole acetamides ( 5 – 8 ) using an easy two step synthetic route. All compounds were tested in vitro against amitochondriate parasites Giardia intestinalis and Trichomonas vaginalis , showing excellent antiprotozoal effects. IC 50 ’s of the most potent compounds range from nanomolar to low micromolar order, being more active than their drugs of choice. Compound 1 (IC 50 = 122 nM), was 44-times more active than Metronidazole, and 10-fold more effective than Nitazoxanide against G. intestinalis and showed good trichomonicidal activity (IC 50 = 2.24 μM). This compound did not display in vitro cytotoxicity against VERO cells. The in vitro inhibitory effect of compounds 1 – 8 and Nitazoxanide against G. intestinalis fructose-1,6-biphosphate aldolase ( Gi FBPA) was evaluated as potential drug target, showing a clear inhibitory effect over the enzyme activity. Molecular docking of compounds 1 , 4 and Nitazoxanide into the ligand binding pocket of Gi FBPA, revealed contacts with the active site residues of the enzyme. Ligand efficiency metrics of 1 revealed optimal combinations of physicochemical and antiprotozoal properties, better than Nitazoxanide. [ABSTRACT FROM AUTHOR]

One-pot multistep stereoselective cascade reactions were implemented for the straightforward synthesis of various nitrocyclitols. Two kinases, an aldolase and a phosphatase were involved in this process, together with a spontaneous intramolecular Henry reaction to provide the nitrocyclitol moiety. The C C bond formation catalysed by the aldolase and the nitroaldol reactions were key steps to build the carbocycle stereoselectively. The aldolase acceptor substrates were all 4-nitrobutanal structurally based, either hydroxylated or unsubstituted at the C2 and/or C3 positions. l -Fuculose-1-phosphate aldolase (FucA) catalysed the formation of the expected ( R , R )- or d -erythro aldol, except in the case of 4-nitrobutanal, from which the epimeric ( R , S )- or l -threo aldol was also formed. l -Rhamnulose-1-phosphate aldolase consistently formed the expected ( R , S )- or l -threo aldol together with a minor amount of ( R , R )- or d -erythro aldol. The intramolecular Henry reaction was also found to be stereoselective, occurring spontaneously once the aldol was formed due to the presence of both ketone and a terminally positioned nitro group. The combination of this set of reactions successfully furnished 11 nitrocyclitols which have not been described previously in the literature. [ABSTRACT FROM AUTHOR]

We employed a minimalist approach for design of an allosterically controlled retroaldolase. Introduction of a single lysine residue into the nonenzymatic protein calmodulin led to a 15,000-fold increase in the second order rate constant for retroaldol reaction with methodol as a substrate. The resulting catalyst AlleyCatR is active enough for subsequent directed evolution in crude cell bacterial lysates. AlleyCatR's activity is allosterically regulated by Ca2+ ions. No catalysis is observed in the absence of the metal ion. The increase in catalytic activity originates from the hydrophobic interaction of the substrate (∼2000-fold) and the change in the apparent p Ka of the active lysine residue. [ABSTRACT FROM AUTHOR]

Glycerol phosphate oxidase from Streptococcus pneumoniae (GPO S.pne ) was purified and characterized. By the actions of GPO S.pne and dihydroxyacetone phosphate (DHAP)-dependent aldolases, various ketoses including rare sugars were synthesized with glyceraldehydes as acceptors in a one-pot four-enzyme system. [ABSTRACT FROM AUTHOR]