Papain Membrane on a Collodion Matrix: Preparation and Enzymic Behavior

Abstract
A stable papain membrane has been prepared on a collodion matrix by absorbing papain in a collodion membrane and then cross-linking the papain with bisdiazobenzidine 3,3′-disulfonic acid. The p H-dependence of the activity of the enzyme membrane on the low-molecular-weight substrate, benzoylarginine ethyl ester, was found to differ from that of crystalline papain; the activity was low in the neutral p H range where the native enzyme has its optimum and high at alkaline p H. This anomalous behavior is due to a lowering of the local p H within the membrane as a result of the release of acid by the enzymic hydrolysis of the ester substrate.