title: On the specificity of sialidase. Synthesis and properties of N5-acetyl-beta-D-neuraminoylpeptides - AcNeu-Gly-OH, AcNeu-Glu-OH, AcNeu-Phe-OH - and the corresponding alpha-ketosides.
abstract: By means of the mixed anhydride procedure the benzyl alpha-ketoside of N5-acetyl-D-neuraminic acid was linked to L-glycine, L-glutamic acid and L-phenylalanine. Hydrogenolytic cleavage of the benzyl group resulted in the corresponding free N5-acetyl-beta-D-neuraminoylpeptides. This new class of compounds is no substrate for Vibrio cholerae sialidase. The enzyme does not split the benzyl alpha-ketosides of N5-acetyl-D-neuraminoylpeptides nor is its activity inhibited by these compounds. The results strongly support the assumption that in sialidase substrates the carboxy group must be located close to the ketosidic oxygen. N-(N5-acetyl-beta-D-neuraminoyl)-L-phenylalanine was readily hydrolysed by carboxypeptidase A from bovine pancreas.
mesh_terms: D000818:Animals; D002268:Carboxypeptidases / Q000378:metabolism; D043422:Carboxypeptidases A; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D005971:Glutamates; D018698:Glutamic Acid; D005998:Glycine; D009439:Neuraminidase / Q000378:metabolism*; D010649:Phenylalanine; D012794:Sialic Acids / Q000138:chemical synthesis* / Q000378:metabolism; D013055:Spectrophotometry, Infrared; D013379:Substrate Specificity; D014734:Vibrio cholerae / Q000201:enzymology
chemical_list: D005971:Glutamates; D012794:Sialic Acids; D018698:Glutamic Acid; D010649:Phenylalanine; D009439:Neuraminidase; D002268:Carboxypeptidases; D043422:Carboxypeptidases A; D005998:Glycine