papaya peptidase a resembles ficin ( ec 3.4.22.3 ) and actinidin ( the cysteine proteinase from actinidin chinenis ) in that it does not appear to possess a carboxy group able to influence the reactivity of the thiol group by change of ionization state at ph values of about 4 , a situation that contrasts markedly with that which obtains in papain .
C0030940
peptidase
C2717970
cysteine proteinase