title: A systematic series of synthetic chromophoric substrates for aspartic proteinases.
abstract: The hydrolysis of the chromogenic peptide Pro-Thr-Glu-Phe-Phe(4-NO2)-Arg-Leu at the Phe-Phe(4-NO2) bond by nine aspartic proteinases of animal origin and seven enzymes from micro-organisms is described [Phe(4-NO2) is p-nitro-L-phenylalanine]. A further series of six peptides was synthesized in which the residue in the P3 position was systematically varied from hydrophobic to hydrophilic. The Phe-Phe(4-NO2) bond was established as the only peptide bond cleaved, and kinetic constants were obtained for the hydrolysis of these peptide substrates by a representative selection of aspartic proteinases of animal and microbial origin. The value of these water-soluble substrates for structure-function investigations is discussed.
mesh_terms: D000818:Animals; D016282:Aspartic Acid Endopeptidases; D001665:Binding Sites; D002417:Cattle; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D003124:Colorimetry; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D009089:Mucor / Q000201:enzymology; D010452:Peptide Biosynthesis; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism*; D013045:Species Specificity; D013379:Substrate Specificity; D013552:Swine
chemical_list: D010455:Peptides; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases