Enzymic Dephosphorylation of Cozymase

Abstract

FOLLOWING the observations^1,2,3 that cozymase is inactivated by vegetable as well as animal tissues it was considered to be of interest to study the mechanism of inactivation. Euler, Adler, Günther and Hellström⁴ found that cozymase was inactivated by dialysed muscle extract, but that the latter was active in glycolysis only when cozymase and adenylic acid were added. They concluded that no adenylic acid was formed and suggested that the inactivation of cozymase might possibly be due to dephosphorylation. The present investigation shows that cozymase is rather slowly dephosphorylated by nucleotidase which dephosphorylates adenylic acid and inosinic acid much more rapidly (the former more easily than the latter). On the other hand, dihydro-cozymase is dephosphorylated about twice as fast as cozymase. In animal tissues cozymase is present in the oxidized as well as in the reduced form, and the present observation might suggest some biological indications.