Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As tools to study structural relationships of cobra venom factor (CVF) and human complement component C3, murine monoclonal antibodies to CVF were produced. In this paper we describe two of these monoclonal anti-CVF antibodies designated GV1.8 and GV1.10, both of which bind to carbohydrate epitopes. On immunoblotting, antibody GV1.8 binds to both the alpha- and beta-chains of CVF, whereas antibody GV1.10 binds only to the alpha-chain of CVF. After enzymatic deglycosylation of CVF with N-glycanase (peptide-N4-(N-acetyl-beta-glucosaminyl) asparagine amidase), both antibodies lose their ability to bind to the deglycosylated protein. Additionally, the free oligosaccharide chains of CVF are able to inhibit the binding of antibodies GV1.8 and GV1.10 to CVF on enzyme-linked immunosorbent assay, further demonstrating their carbohydrate specificity. Both monoclonal antibodies to CVF cross-react with human C3. Antibody GV1.8 binds to both chains of human C3 indicating that the shared antigenic epitope present on the two glycosylated chains of CVF is also present on the two chains of human C3. Antibody GV1.10 cross-reacts only with the beta-chain of human C3 which is the homologous chain to the alpha-chain of CVF. After enzymatic deglycosylation of human C3 by N-glycanase, both antibodies lose their ability to bind to the deglycosylated protein consistent with the carbohydrate nature of the recognized epitopes. These results indicate that CVF and human C3 share carbohydrate epitopes on their homologous and nonhomologous chains.
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PMID:Cobra venom factor and human C3 share carbohydrate antigenic determinants. 244 Sep 48

A thrombin-like enzyme was isolated in 6% yield from the venom of Crotalus durissus terrificus by ammonium sulfate precipitation followed by gel filtration on Sephadex G-75 and finally affinity chromatography on Sepharose-1,4-butanediol-diglycyl-p-aminobenzamide eluted with 0.15 M benzamidine. The enzyme behaved like a single component on SDS-PAGE corresponding to a molecular weight of 34 kDa. The specific activity of the enzyme toward bovine fibrinogen was 71 NIH U/mg protein. The pH optimum for the coagulation of human fibrinogen was 8.0. The enzyme hydrolyzes the alpha-chain of fibrinogen, has amidase activity on L-arginine-p-nitroanilide and L-arginine-7-amido-4-methyl-coumarin amino terminal blocked peptides and presents esterolytic activity on N-alpha-tosyl-L-arginine-methylester.
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PMID:Isolation and characterization of a thrombin-like enzyme from the venom of Crotalus durissus terrificus. 359

In Streptomyces davawensis roseoflavin is synthesized from GTP and ribulose-5-phosphate through riboflavin. As a first step towards the molecular analysis of flavin metabolism in S. davawensis the genes involved in riboflavin biosynthesis were cloned by hybridization of heterologous probes to a genomic library on a high-density colony-array. The genes ribB (riboflavin synthase, alpha-chain; EC 2.5.1.9), ribM (putative membrane protein), ribA (bifunctional GTP cyclohydrolase II/3,4-dihydroxy-2-butanone-4-phosphate synthase; EC 3.5.4.25) and ribH (lumazine synthase; EC 2.5.1.9) are organized in an operon-like cluster. Northern blot analysis of this cluster revealed two transcripts of 1.7 and 3.1 kb, respectively. The gene ribB was overexpressed in Escherichia coli. The specific riboflavin synthase activity in a cell-free extract of a recombinant strain was 0.246 nmol mg(-1 )min(-1). Overexpression of ribM enhanced the transport of riboflavin in the corresponding recombinant E. coli strain. Furthermore, overexpression of ribM increased roseoflavin sensitivity of E. coli. On another subgenomic fragment a putative S. davawensis ribG gene coding for the missing pyrimidine deaminase/reductase (EC 3.5.4.26 and EC 1.1.1.193) of the riboflavin biosynthetic pathway and ribY coding for a second (monofunctional) GTP cyclohydrolase II were identified.
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PMID:Identification and characterization of two Streptomyces davawensis riboflavin biosynthesis gene clusters. 1754 77