Multiple Forms and Some Properties of Alkaline Phosphatase Produced by Aspergillus oryzae on Solid Medium

Abstract

Three forms of alkaline phosphatase (Al-PMase) (EC. 3.1.3.1)were partially purified from Aspergillus oryzae grown on a bread medium which was in a phosphate-restricted condition. The purified enzymes were named Al-PMase I, II, and III, with pH optima at about pH 8, 99.5, and 10, respectively. Al-PMase II seems to be a major component in the Al-PMases of this fungus. The enzymes were satisfactorily stable at pH 710 at 30°C. Al-PMase I, II, and III were subjected to competitive inhibition with phosphate and commonly inhibited with Hg²⁺ and Mn²⁺. Al-PMase I and II were inhibited completely with EDTA, but Al-PMase III was insensitive to EDTA. Al-PMase II and III seemed to be a non-specific alkaline phosphatase. Al-PMase I showed less affinity to 5'-nucleic acids than 2'(3')-nucleic acids, and did not hydrolyze α-naphthyl phosphate, α-glycerophosphate, O-phosphoethanolamine, and phosphorylcholine.