The deaminases of adenosine and adenylic acid in blood and tissues

Abstract

IN this paper an account is given of the activity of these enzymes as they appear in blood and tissue extracts. Whereas the deaminase of adenosine acts therein as one may expect, that of adenylic acid has certain unusual characteristics. The most striking fact is the great susceptibility of the adenylic deaminase to the inhibiting action of certain anions, though the anions of maleic and citric acids are practically without effect; besides which, there are other inhibiting substances in tissues (probably anions also) but not in voluntary muscle. The result of their action is a protection of the adenylic acid as it forms in tissues generally and a simulation of a proportionality of action to substrate concentration. From such effects also it may be occasionally concluded that adenylic acid deaminase is absent or in very small concentration when in fact very appreciable amounts are present.