A creatininase produced from a Arthrobacter sp. was purified 145-fold by a series of steps including heat treatment, ammonium sulfate precipitation, DEAE-Cellulose ion-exchange and hydrophobic chromatography. The specific activity of the pure enzyme was 209u/mg. The subunit molecular mass of creatininase was estimated to be 33 700D by SDS-PAGE. The creatininase was stable in the pH range between 6.0 - 9.0 and below 60 degrees C . Its Km value for creatinine was estimated to be 21.14 mmol/L. The enzyme was markedly inactivated by incubation with 1 mmol/L of Hg2+, Ag2+, Li+, Cu2+ and 20 mmol/L of 1, 11-Phananthroline respectively. Activation was observed when the enzyme was incubated with 1 mmol/L of Co2+ and Mn2+.
Amidohydrolases ; isolation & purification ; metabolism ; Arthrobacter ; enzymology ; Bacterial Proteins ; isolation & purification ; metabolism ; Chromatography, DEAE-Cellulose ; methods

Nitriles are an important type of synthetic intermediates in the production of fine chemicals because of their easy preparations and versatile transformations. The traditional chemical conversion of nitriles to carboxylic acids and amides is feasible but it requires relatively harsh conditions of heat, acid or alkali. Nitrile converting enzymes (nitrilase, nitrile hydratase and amidase) which are used as biocatalyst for the production of fine chemicals have attracted substantial interest because of their ability to convert readily available nitriles into the corresponding higher value amides or acids under mild conditions with excellent chemo-, regio- and stereo-selectivities. Many nitrile converting enzymes have been explored and widely used for the production of fine chemicals. In this paper, various examples of biocatalytic synthesis of pharmaceuticals and their intermediates, agrochemicals and their intermediates, food and feed additives, and other fine chemicals are presented. In the near future, an increasing number of novel nitrile converting enzymes will be screened and their potential in the production of useful fine chemicals will be further exploited.
Amides ; metabolism ; Amidohydrolases ; metabolism ; Aminohydrolases ; metabolism ; Carboxylic Acids ; metabolism ; Chemical Industry ; methods ; Hydro-Lyases ; metabolism ; Nitriles ; chemistry

A stable Zr-based metal-organic framework (MOF, UiO-66-NH2) synthesized via micro-water solvothermal method was used to immobilize amidase by using the glutaraldehyde crosslinking method. The effect of immoblization conditions on enzyme immoblization efficiency was studied. An activity recovery rate of 86.4% and an enzyme loading of 115.3 mg/g were achieved under the optimal conditions: glutaraldehyde concentration of 1.0%, cross-linking time of 180 min, and the weight ratio of MOF to enzyme of 8:1. The optimal temperature and optimal pH of the immobilized amidase were determined to be 40 °C and 9.0, respectively, and the Km, Vmax and kcat of the immoblized amidase were 58.32 mmol/L, 16.23 μmol/(min·mg), and 1 670 s⁻¹, respectively. The immobilized enzyme was used for (S)-4-fluorophenylglycine synthesis and the optimal reaction conditions were 300 mmol/L of N-phenylacetyl-4-fluorophenylglycine, 10 g/L of immobilized enzyme loading, and reacting for 180 min at pH 9.0 and 40 °C. A conversion rate of 49.9% was achieved under the optimal conditions, and the conversion rate can be increased to 99.9% under the conditions of enantiomeric excess. The immobilized enzyme can be repeatedly used, 95.8% of its original activity can be retained after 20 cycles.
Amidohydrolases ; Enzyme Stability ; Enzymes, Immobilized/metabolism* ; Glycine/analogs & derivatives* ; Hydrogen-Ion Concentration ; Metal-Organic Frameworks ; Temperature

In order to analyze the correlation between critical residues in the catalytic centre of BSH and the enzyme substrate specificity, seven mutants of Lactobacillus salivarius bile salt hydrolase (BSH1) were constructed by using the Escherichia coli pET-20b(+) gene expression system, rational design and site-directed mutagenesis. These BSH1 mutants exhibited different hydrolytic activities against various conjugated bile salts through substrate specificities comparison. Among the residues being tested, Cys2 and Thr264 were deduced as key sites for BSH1 to catalyze taurocholic acid and glycocholic acid, respectively. Moreover, Cys2 and Thr264 were important for keeping the catalytic activity of BSH1. The high conservative Cys2 was not the only active site, other mutant amino acid sites were possibly involved in substrate binding. These mutant residues might influence the space and shape of the substrate-binding pockets or the channel size for substrate passing through and entering active site of BSH1, thus, the hydrolytic activity of BSH1 was changed to different conjugated bile salt.
Amidohydrolases ; genetics ; metabolism ; Bile Acids and Salts ; metabolism ; Escherichia coli ; metabolism ; Gene Expression ; Lactobacillus ; enzymology ; genetics ; Substrate Specificity

OBJECTIVETo investigate the expression and activity of fatty acid amide hydrolase (FAAH) in the colon and its role in children with slow transit constipation (STC).

METHODSPatients were divided into constipation group (n=21) and control group (n=15). The constipation group was consistent with the diagnostic criteria for STC. Western blotting, immunohistochemistry and real-time PCR were used to examine the FAAH expression in surgical specimen of colon. The location and distribution of FAAH and cannabinoid receptor type 1 (CB1) were detected by immunofluorescence double staining. The biological activity of colon FAAH was detected by high-performance liquid chromatography.

RESULTSWestern blotting revealed that FAAH protein expression in the ascending colon, descending colon and sigmoid colon were significantly decreased in the myenteric neurons and absorption cells in the constipation group as compared with the control group (8.68+/-3.4 vs 10.47+/-3.7, 8.21+/-1.2 vs 9.95+/-6.4, 8.01+/-7.2 vs 9.79+/-3.4, all P<0.05). The same results were found by immunohistochemistry and real-time PCR. The FAAH hydrolysis activity in the ascending colon, descending colon or sigmoid colon decreased significantly in the constipation group, as compared with the control group [(0.51+/-0.23) nmol x min(-1) x mg(-1) vs (0.84+/-0.24) nmol x min(-1) x mg(-1), (0.39+/-0.25) nmol x min(-1) x mg(-1) vs (0.55+/-0.44) nmol x min(-1) x mg(-1), (0.35+/-0.37) nmol x min(-1) x mg(-1) vs (0.58+/-0.48) nmol x min(-1) x mg(-1), all P<0.05].

CONCLUSIONFAAH expression and hydrolysis activity in the colon decrease in children with STC. FAAH may play a role in the pathogenesis of slow transit constipation in Children.

Adolescent ; Amidohydrolases ; metabolism ; Case-Control Studies ; Child ; Child, Preschool ; Chronic Disease ; Colon ; metabolism ; Constipation ; metabolism ; Female ; Humans ; Male

The present study analyzed the correlations between curcumin(Cur), nuclear factor E2 related factor 2(NRF2)-dimethylarginine dimethylaminohydrolase(DDAH)-asymmetric dimethylarginine(ADMA)-nitric oxide(NO) pathway, and endothelial-mesenchymal transition(EndMT) based on SD rats with cardiac fibrosis, and explored the effect and mechanism of Cur in resisting cardiac fibrosis to provide an in-depth theoretical basis for its clinical application in the treatment of heart failure. The cardiac fibrosis model was induced by subcutaneous injection of isoprenaline(Iso) in rats. Thirty-two rats were randomly divided into a control group, a model group, a low-dose Cur group(100 mg·kg~(-1)·d~(-1)), and a high-dose Cur group(200 mg·kg~(-1)·d~(-1)), with eight in each group. After 21 days of treatment, cardiac function was detected by echocardiography, degree of cardiac fibrosis by Masson staining, expression of CD31 and α-SMA by pathological staining, expression of VE-cadherin, vimentin, NRF2, and DDAH by Western blot, and ADMA level by HPLC. Compared with the model group, the Cur groups showed alleviated cardiac fibrosis, accompanied by increased CD31 and VE-cadherin expression and decreased α-SMA and vimentin expression, indicating relieved EndMT. Additionally, DDAH and NRF2 levels were elevated and ADMA and NO expression declined. Cur improves cardiac fibrosis by inhibiting EndMT presumedly through the NRF2-DDAH-ADMA-NO pathway.
Amidohydrolases/metabolism* ; Animals ; Curcumin ; Fibrosis ; NF-E2-Related Factor 2/genetics* ; Nitric Oxide/metabolism* ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To analyze the molecular etiology of a Chinese child affected with dihydropyrimidinase deficiency. METHODS: Genomic DNA was extracted from peripheral blood samples of the family members. Pathogenic variant was determined by whole exome sequencing and verified by Sanger sequencing. RESULTS: The child was found to harbor homozygous c.905G>A (p.Arg302Gln) variants in exon 5 of the DPYS gene, for which her parents were both heterozygous carriers. CONCLUSION The homozygous c.905G>A (p.Arg302Gln) variants of the DPYS gene probably underlies the dihydropyrimidinase deficiency in the child. Above result has enabled genetic counseling and prenatal diagnosis for this family.
Amidohydrolases/genetics* ; Asian Continental Ancestry Group/genetics* ; Child ; Exons ; Female ; Humans ; Metabolism, Inborn Errors/genetics* ; Mutation ; Pedigree

The cultural conditions for the growth of Norcardia cell were studied in this paper. Controlling pH value, adding nutrient and optimizing the quantity of inducer during cultivation, the activity of nitrile hydratase reached 6567 u/mL (culture medium), which was the highest value appeared in native journals. In the farther hydratase experiments, no by-product, crylic acid, was detected. It showed that the activity of amidase was not promoted obviously while the activity of nitrile hydratase was increased greatly. The results set a strong foundation for the industrial application and the research on new technology.
Acrylamides ; metabolism ; Amidohydrolases ; metabolism ; Biotechnology ; methods ; Cell Culture Techniques ; Fermentation ; physiology ; Glucose ; metabolism ; Hydro-Lyases ; metabolism ; Hydrogen-Ion Concentration ; Nocardiaceae ; enzymology ; metabolism

Hydantoin-utility-enzyme is widely used in enzymic production of various amino acids. One of its component, carbamoylase, is responsible for the conversion of N-carbamylamino acids to corresponding amino acids, which is crucial for the stereoselectivity and rate limiting. To improve the production of the enzyme, an L-N-carbamoylase gene from Arthrobacter BT801, a hydantoinase producting strain being able to convert 5-benzylhydantoin to phenylalanine, was cloned into E. coli. The gene was highly expressed in E. coli M15 under control of T5 promoter. A protein band about 44kD was detected by SDS-PAGE in the recombinant cell lysate. The objective product, which is principally in soluble form, represented 40% of total cell protein. The N-carbamoylase specific activity of the recombinant M15/pQE60- hyuC is 53 times higher than that of Arthrobacter BT801. The total biotransformation activity increased 8.1 times when. M15/pQE60-hyuC was added into the Arthrobacter BT801 reaction system. The successful expression of the enzyme is significant for the application of the hydantoinase producing strain or the enzyme thereof.
Amidohydrolases ; genetics ; metabolism ; Arthrobacter ; enzymology ; genetics ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Hydantoins ; metabolism ; Models, Genetic ; Phenylalanine ; metabolism ; Plasmids ; genetics ; Polymerase Chain Reaction

Developing a high-throughput screening method is of great importance for directed evolution of atrazine chlorohydrolase. A mutagenesis library of atzA from Pseudomonas sp. ADP and Arthrobacter sp. AD1 was constructed using error-prone PCR and DNA shuffling. Candidate mutants were screened through Haematococcus pluvialis expression system, using atrazine as selection pressure. Sequence analysis showed that mutations in the obtained 12 mutants with enhanced activity were all point-substitutions and scattered throughout the gene. Enzymatic activity analysis showed that the mutants all had higher activities than that of the wild type. The activities were 1.8-3.6 fold of the wild-type enzyme when cultured in BBM medium with 1 mg/L atrazine, whereas 1.8-2.6 fold with 2 mg/L atrazine. These results indicated that Haematococcus pluvialis expression system is an ideal high throughput screening system for directed evolution of atrazine chlorohydrolase.
Amidohydrolases ; genetics ; Atrazine ; metabolism ; Bacterial Proteins ; genetics ; Biodegradation, Environmental ; Chlorophyta ; genetics ; metabolism ; Herbicides ; metabolism ; High-Throughput Screening Assays ; Hydrolases ; biosynthesis ; genetics ; Mutagenesis, Insertional ; Pseudomonas ; enzymology ; genetics