Isolation and identification of enkephalins in pedal ganglia of Mytilus edulis (Mollusca).

Abstract

An acid extract of pedal ganglia of the mollusk M. edulis was fractionated by high-pressure liquid chromatography with a reverse-phase column. Peak fractions with retention times of those of [Met]- and [Leu]enkephalin were subjected to binding assays in both invertebrate and vertebrate tissues. These fractions have the same binding activities as authentic enkephalins. Peptides from these fractions were purified by high-pressure liquid chromatography under isocratic conditions. Sequential amino acid analyses showed that these peptides have the same primary structures as [Met]- and [Leu]enkephalin. These results with M. edulis suggest that invertebrates possess an enkephalinergic system similar to that of higher organisms.