Catabolism of N‐Acylethanolamine Phospholipids by Dog Brain Preparations

Publisher Website
Google Scholar
Abstract
N-Acylphosphatidylethanolamine, incubated with dog brain homogenate or microsomes, was hydroyzed to phosphatidic acid and N-acylethanolamine by a phosphodiesterase of the phospholipase D type. In the absence of F−, phosphatidic acid was further hydrolyzed to diacylglycerol and Pi while N-acylethanolamine was hydrolyzed by an amidase to fatty acid and ethanolamine. The phosphodiesterase showed an alkaline pH optimum and was also active towards N-acetylphosphatidyletha-nolamine, N-acyl-lysophosphatidylethanolamine, and glycerophospho(N-acyl)ethanolamine but showed little activity toward phosphatidylethanolamine and phosphati-dylcholine. Ca2+ stimulated slightly at low concentrations but inhibited at higher concentrations. Triton X-100 stim ulated the hydrolysis of N-acylphosphatidylethanol-amine, inhibited that of N-acyl-lysophosphatidyletha-nolamine and glycerophospho(N-acyl)ethanolamine, and had no effect on phosphatidylethanolamine or phospha-tidylcholine hydrolysis. The N-acylethanolamine hydrolase (amidase) was also present in the microsomal fraction and exhibited a pH optimum of 10.0. In addition to hydrolysis by the phosphodiesterase, N-acylphosphati-dylethanolamine was also catabolized by microsomal phospholipases A1 and/or A2 to N-acyl-lysophosphati-dylethanolamine, some of which was further hydrolyzed to glycerophospho(N-acyl)ethanolamine.

This publication has 21 references indexed in Scilit: