Enzymatic synthesis and decarboxylation of phosphatidylserine in Tetrahymena pyriformis

Abstract

Cell-free extracts of the protozoan Tetrahymena pyriformis have been found to catalyze the following reactions: Phosphatidylethanolamine+L-Serine⇌Phosphatidylserine+EthanolaminePhosphatidylserine→Phosphatidylethanolamine+CO2Net:L-Serine→Ethanolamine+CO2The biosynthesis of phosphatidylserine in this organism resembles that found in higher animals. In contrast, phosphatidylserine is formed in bacteria in a reaction between CDP-diglyceride and l-serine. A detailed description is presented of the enzyme that catalyzes the synthesis of phosphatidylserine in Tetrahymena by the exchange reaction, together with some properties of the phosphatidylserine decarboxylase in this organism.

Keywords

• biosynthesis
• exchange enzyme
• mechanism
• phosphatidylethanolamine
• phosphatidylserine decarboxylase
• phospholipids