[Phosphoenolpyruvate carboxykinase in Phycomyces blakesleeanus Bgff. (author's transl)].

Phosphoenolpyruvate carboxykinase (PEPCK) from Phycomyces blakesleeanus was partially purified by protamine sulfate precipitation, ammoniumsulfate precipitation, and diethylamino ethyl cellulose (DEAE) treatment. This preparation was employed for the characterization of the enzyme. The Km values for phosphoenolpyruvate (PEP) and ADP were determined as 1.6 and 0.42 mM. The nucleotid specificity was demonstrated for ADP exclusively. The use of sulfuryl reagents showed the presence of thiol groups sensitive against p-hydroxymercuribenzoate but not effected by N-ethylmaleimide.