Phosphatidylserine decarboxylase from Escherichia coli

Abstract

The phosphatidylserine decarboxylase of Escherichia coli is associated with the cytoplasmic membrane and requires nonionic detergent for solubilization and detection of enzymatic activity. The enzyme catalyzes decarboxylation through formation of a Schiff base between the amine of the substrate and the carbonyl residue of its pyruvate prosthetic group. The prosthetic group is covalently bound in an amide linkage to the amino terminus of the smaller (α-subunit) of the two subunits of the enzyme. The most widely used assay for the phosphatidylscrine decarboxylase measures the release of 14CO2 from phosphatidyl-L-[l-14C]serine. The phosphatidylserine decarboxylase is most stable in the pH range..