these disulphides were used as reactivity probes to investigate specificity and binding-site-catalytic-site signalling in a number of cysteine proteinases by determining ( a ) the reactivity at ph 6.0 at 25 degrees c at i 0.1 of compound ( iii ) ( a close analogue of a good papain substrate ) towards 2-mercaptoethanol , benzimidazol-2-ylmethanethiol [ compound ( v ) , as a minimal catalytic-site model ] , chymopapains b1-b3 , chymopapain a , papaya proteinase omega , actinidin , cathepsin b and papain , ( b ) the effect of changing the structure of the probe as indicated above on the reactivities of compound ( v ) and of the last five of these enzymes , and ( c ) the forms of ph-dependence of the reactivities of papain and actinidin towards compound ( iii ) .
C2717970
cysteine proteinases
C0699919
cathepsin b