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)

The enzymes of N-acetyl-D-glucosamine (GlcNAc) metabolism, GlcNAc-6-phosphate deacetylase and GlcN-6-phosphate deaminase were found to be inducible in Candida albicans. The pattern of induction for these enzymes was the same under conditions of germ-tube formation (37 degrees C) and where yeast cells metabolized GlcNAc with no change in morphology (28 degrees C); this indicates that these enzymes are not control points in the dimorphic development of C. albicans. During induction there was a 40-and 25-fold increase in specific activity for the deacetylase and the deaminase, respectively, and the maximum specific activity correspond to the time when all the GlcNAc had been metabolized. The presence of lomofungin (an inhibitor of transcription) or trichodermin (an inhibitor of translation) in cell suspensions of C. albicans containing GlcNAc prevented the increase in specific activity of these enzymes. 2-Deoxyglucose inhibited germ-tube formation, partially inhibited the induction of the deacetylase (43%) and the deaminase (60%), but did not affect the growth of C. albicans on either Glc or GlcNAc. GlcN-6-phosphate was a competitive inhibitor of the deacetylase with a Ki of 1.4 mM while the other product of the reaction, acetate, did not inhibit the enzyme. The Km value for GlcN-6-phosphate on GlcN-6-phosphate deaminase was 0.24 mM. Incubation of starved yeast cells with GlcNAc produced a four-fold increase in the specific activity of UDP-GlcNAc-pyrophosphorylase at either 28 degrees C or 37 degrees C.
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PMID:Enzymes of N-acetylglucosamine metabolism during germ-tube formation in Candida albicans. 629 72

We investigated the specificity of glycosyltransferases toward donor substrates in two complementary directions. First we prepared simple N-acetyl-alpha-D-glucosamine 1-diphosphates: methyl-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-diphosphate, benzyl-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-diphosphate, 4-phenylbutyl-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-diphosphate, by the coupling of the corresponding activated alkyl phosphates with N-acetyl-alpha-D-glucosamine 1-phosphate. These diphosphates as well as 2-acetamido-2-deoxy-alpha-D-glucopyranose 1-diphosphate, tested as donors of N-acetylglucosamine in a reaction catalyzed by Neisseria meningitidis N-acetylglucosaminyltransferase (LgtA), proved to be devoid of activity. Evaluated as inhibitors, only 2-acetamido-2-deoxy-alpha-D-glucopyranose 1-diphosphate showed some inhibitory activity with an IC50 value of 7 mM. In the second approach, we prepared sugar nucleotide mimics having the diphosphate bridge replaced by the oxycarbonylaminosulfonyl linker. The surrogate of GDP-Fuc was synthesized as a 9:1 alpha/beta anomeric mixture, in 40% yield, starting from chlorosulfonyl isocyanate, perbenzylated l-fucopyranose, and a guanosine derivative, protected on the exocyclic amine and secondary hydroxyl functions of ribose. Then two deprotection steps, hydrogenolysis and enzymatic hydrolysis catalyzed by penicillin G amidase afforded the target molecule to be tested as fucose donor with recombinant human alpha-(1-->3/4)-fucosyltransferase (FucT-III). Tested as a 4:1 alpha/beta anomeric mixture, both in the absence and in the presence of cationic cofactors, this new guanosine fucose conjugate proved to be ineffective. Its inhibitory activity toward FucT-III evaluated through a competition fluorescence assay was very poor (IC50 value of 20 mM). The surrogate of UDP-GlcNAc that was already known as its protected acetylated derivative, tested as N-acetylglucosamine donor with LgtA in the presence of Mn(2+) turned out not to be active either.
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PMID:Exploring specificity of glycosyltransferases: synthesis of new sugar nucleotide related molecules as putative donor substrates. 1804 19