title: Active-site titration of serine proteinases acting selectively on cationic substrates by N-alpha-carbobenzoxy-L-arginine p-nitrophenyl ester and N-alpha-carbobenzoxy-L-lysine p-nitrophenyl ester; determination of active enzyme concentration.
abstract: A titration method for determination of trypsin-like serine proteinase concentration has been developed by using ZArgONp and ZLysONp, two specific chromogenic amino-acid derivatives which show the characteristics of optimal active-site titrants. Active proteinase concentration has been estimated from the effect of titrant concentration on the amplitude, at time zero, of the time-course for the instantaneous release of p-nitrophenol, preceding the steady-state reaction (burst phase).
mesh_terms: D000721:Ancrod / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000378:metabolism; D001665:Binding Sites; D006801:Humans; D007610:Kallikreins / Q000378:metabolism; D007700:Kinetics; D008239:Lysine / Q000031:analogs & derivatives* / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism*; D013053:Spectrophotometry; D013917:Thrombin / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: C040761:N-benzyloxycarbonylarginine 4-nitrophenyl ester; C034117:N-benzyloxycarbonyllysine 4-nitrophenyl ester; D001120:Arginine; D000721:Ancrod; D007610:Kallikreins; D012697:Serine Endopeptidases; D014357:Trypsin; D013917:Thrombin; D014568:Urokinase-Type Plasminogen Activator; D008239:Lysine