[p-Nitroanilides of amino acids and peptides and fluorescence peptide with inner fluorescence quenching as substrates for cathepsins H, B, D and high molecular weight aspartic peptidase in the brain].
p-Nitroanilides of amino acids and peptides were used to study the specificity of cathepsins H and B from human and bovine brain, respectively. The specific activity of cathepsin H decreased in the following order: Arg-pNa greater than or equal to Leu-pNa greater than Ala-pNa greater than or equal to Phe-pNa greater than Pro-pNa greater than Glu-pNa; Arg-pNa was split by the enzyme 12 times as fast as Bz-Arg-pNa. Among other oligopeptide p-nitroanilides tested (Ala-Ala, Ala-Leu, Ala-Ala-Ala, Ala-Ala-Leu, Gly-Gly-Leu, Gly-Gly-Phe, Gly-Leu-Phe, pGlu-Phe-Leu, pGlu-Phe-Ala, pGlu-Phe), PGlu-Phe-Leu and pGlu-Phe-Ala appeared to be the best substrates for cathepsin B; Km for hydrolysis were 0.1 mM and 0.165 mM, respectively, kcat were 5.1 and 8.3 s-1, respectively. A comparative study of substrate specificity of cathepsin D and high molecular weight aspartic peptidase with the use of fluorescent substrate with inner fluorescence quenching, Abz-Ala-Ala-Phe-Phe-pNa, revealed that both peptidases hydrolyzed the single bond between two phenylalanine residues, resulting in the increase of fluorescence (4.5-5-fold) of anthraniloyl tripeptide. The Km values for the substrate hydrolysis by cathepsin D and high molecular weight aspartic peptidase were 6.2 microM and 11.2 microM; kcat were 7.2 s-1 and 1.3 s-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Azarian
A V
AV
Agatian
G L
GL
Galoian
A A
AA
D000596:Amino Acids; D000813:Anilides; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D001921:Brain / Q000201:enzymology*; D002401:Cathepsin B / Q000378:metabolism; D002402:Cathepsin D / Q000378:metabolism; D056655:Cathepsin H; D002403:Cathepsins / Q000378:metabolism*; D002417:Cattle; D003546:Cysteine Endopeptidases; D010450:Endopeptidases / Q000378:metabolism*; D005456:Fluorescent Dyes; D006801:Humans; D007700:Kinetics; D009842:Oligopeptides; D013379:Substrate Specificity
D000596:Amino Acids; D000813:Anilides; D005456:Fluorescent Dyes; D009842:Oligopeptides; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; C534126:CTSH protein, human; D056655:Cathepsin H; D016282:Aspartic Acid Endopeptidases; D002402:Cathepsin D
p-Nitroanilidy aminokislot i peptidov i fluorestsentnyĭ peptid s vnutrennim tusheniem fluorestsentsii kak substraty katepsinov H, B, D i vysokomolekuliarnoĭ aspartil'noĭ peptidazy golovnogo mozga.