Abstract
The decarboxylation of phosphatidylserine to phosphatidylethanolamine was studied in homogenate and subcellular fractions of mouse liver. Among phosphatidylserine decarboxylases of various subcellular fractions, the enzyme of the nucleic fraction was found to be inhibited by various inhibitors to pyridoxal phosphate enzymes. The enzyme of nucleic fraction could be extracted by 2M NaCl solution, and the solubilized enzyme was still more further inhibited by the inhibitors. Deoxypyridoxine also inhibited the enzyme and the inhibition was completely removed by the addition of pyridoxal phosphate. Furthermore, pyridoxal phosphate and Mn^<2+> catalyzed nonenzymatically the decarboxylation of phosphatidylserine to phosphatidylethanolamine. These results seem to show that phosphatidylserine decarboxylase may be pyridoxal phosphate dependent.
