Kinetics and mechanism of catalysis by proteolytic enzymes. A comparison of the kinetics of hydrolysis of synthetic substrates by bovine alpha- and beta-trypsin.
Several esters of the alpha-N-toluene-p-sulphonyl and alpha-N-benzoyl derivatives of S-(3-aminopropyl)-l-cysteine and the methyl ester of S-(4-aminobutyl)-N-toluene-p-sulphonyl-l-cysteine were synthesized. The kinetics of hydrolysis of these and esters of the alpha-N-toluene-p-sulphonyl and alpha-N-benzoyl derivatives of l-arginine, l-lysine, S-(2-aminoethyl)-l-cysteine and esters of gamma-guanidino-l-alpha-toluene-p-sulphonamidobutyric acid and alpha-N-toluene-p-sulphonyl-l-homoarginine by alpha- and beta-trypsin were compared. On the basis of values of the specificity constants (k(cat.)/K(m)), the two enzymes display similar catalytic efficiency towards some substrates. In other cases alpha-trypsin is less efficient than beta-trypsin. It is possible that alpha-trypsin possesses greater molecular flexibility than beta-trypsin.
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives; D002384:Catalysis; D002417:Cattle; D003201:Computers; D003545:Cysteine / Q000031:analogs & derivatives; D004952:Esters; D006146:Guanidines / Q000031:analogs & derivatives; D007700:Kinetics; D008239:Lysine / Q000031:analogs & derivatives; D013053:Spectrophotometry; D013329:Structure-Activity Relationship; D014105:Tosyl Compounds; D014357:Trypsin
D004952:Esters; D006146:Guanidines; D014105:Tosyl Compounds; D001120:Arginine; D014357:Trypsin; D008239:Lysine; D003545:Cysteine