[Properties of the phospholipases C from Bacillus cereus]

Abstract

Three different phospholipases C--the so-called phospholipase C which hydrolyses phosphatidylcholine (Pch-PLC), sphingomyelinase (SM-PLC) and phosphatidylinositol hydrolysing phospholipase C (PI-PLC)--were separated from the culture filtrate of Bacillus cereus using column chromatography on DEAE-sephadex A-50. The pI values were estimated to be 5.0 +/- 0.3 for PI-PLC and 5.3 +/- 0.2 for SM-PLC. The effect of some bivalent cations was studied. Metal ions had no effect on the activity of PI-PLC, whereas Mg2+ and Co2+ in concentrations from 1 to 5 mM highly activated SM-PLC. Mg2+ failed to activate PCh-PLC, and Co2+ even inhibited it. EDTA of o-phenantroline had a rather inhibitory effect on Pch-PLC, but they almost did not affect SM-PLC.