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)

N4-Long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase, a metabolizing enzyme for N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with long-chain fatty acids, was purified from mouse liver microsomes. The purification was accomplished by solubilization of liver microsomes with Triton X-100, diethylaminoethyl cellulose chromatography, gel filtrations, hydroxyapatite chromatography, and concanavalin A:Sepharose chromatography. On sodium dodecyl sulfate:polyacrylamide gel electrophoresis, the purified enzyme preparation produced a single protein band with a molecular weight of 54,000. The enzyme had an optimal pH of 9.0, and the Michaelis constant for N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was 67 microM. The thiols such as dithiothreitol or 2-mercaptoethanol stabilized the enzyme and stimulated its activity. p-Chloromercuribenzoate, N-ethylmaleimide, diisopropylfluorophosphate, and phenylmethylsulfonyl fluoride strongly inhibited the reaction. Bovine serum albumin markedly stimulated the enzyme activity, whereas detergents such as Triton X-100, deoxycholate, and sodium dodecyl sulfate had little effect. The enzyme did not require monovalent or divalent cations. Among the series of N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with different chain lengths of acyl residues, the purified enzyme preferentially hydrolyzed the derivatives with long-chain fatty acids (C12 to C18), and N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was the most susceptible. The purified enzyme was inactive on various N-acylamino acids, amides, oligopeptides, proteins, N-acylsphingosines (ceramides), triglyceride, lecithin, and lysolecithin. These results suggest that N4-long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase may be a new type of linear amidase.
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PMID:Purification and characterization of an amidohydrolase for N4-long-chain fatty acyl derivatives of 1-beta-D-arabinofuranosylcytosine from mouse liver microsomes. 669 3

L-Amino acid acylase and D-amino acid acylase were stable below 50 degrees C, although the D-enzyme was more thermostable than the L-enzyme at higher temperatures. At 30 degrees C they showed the highest reaction velocity in phosphate buffer of pH 7.4. Hg++ and Cu++ severely inactivated their activity. Activation by Co++ was observed on L-amino acid acylase, but not on D-amino acid acylase. p-Chloromercuribenzoate inhibited both enzymes, whereas ethylenediamine tetraacetate was very inhibitory on L-amino acid acylase only. With N-acetyl- and N-chloroacetyl-amino acids as substrates, they were relatively stereo-specific. They acted as a peptidase on dipeptides and tripeptides. Although N-acetylglycine was attacked by the two enzymes, N-acetylglucosamine and N-acetylethanolamine were insusceptible. PS-5 was converted to NS-5 (deacetyl PS-5) by L-amino acid acylase as well as by D-amino acid acylase.
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PMID:Deacetylation of PS-5, a new beta-lactam compound. III. Enzymological characterization of L-amino acid acylase and D-amino acid acylase from Pseudomonas sp. 1158. 741 69