Substrate stereospecificity of phosphatidylinositol-specific phospholipase C from Bacillus cereus examined using the resolved enantiomers of synthetic myo-inositol 1-(4-nitrophenyl phosphate)

Resolved optical isomers of synthetic myo-inositol 1-(4-nitrophenyl phosphate), which is a chromogenic substrate for phospholipase, was used to study the substrate stereospecificity of phosphatidyl-inositol specific phopholipase C (PI-PLC) from Bacillus cereus. Synthetic D and L enantiomers of the chromogenic substrate were prepared to subjected to cleavage by PI-PLC. The obtained values for the initial rates of cleavage indicate that PI_PLC is stereospecific for the D enantiomer. Moreover, enzyme active site sensitivity to the stereochemistry of the myo-inositol group was demonstrated.