H. Y. Yang, W. Fratta, E. Majane
Nov 1, 1985
Citations
18
Influential Citations
566
Citations
Quality indicators
Journal
Proceedings of the National Academy of Sciences of the United States of America
Abstract
Two peptides that crossreact with an antiserum raised against Phe-Met-Arg-Phe-NH2 were purified from bovine brain extract. Their structures were determined to be Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe- NH2 and Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2. The sequences were determined by gas-phase sequencing, except for the COOH-terminal phenylalaninamides. These were assigned on the basis of the reactivity of the peptides with the anti-Phe-Met-Arg-Phe-NH2 antiserum, which appears to recognize the determinant -Arg-Phe-NH2. Both peptides were synthesized, and the synthetic peptides were found to have the same HPLC retention times as the endogenous Phe-Met-Arg-Phe-NH2-immunoreactive peptides, thus confirming the assignment of phenylalaninamide to the COOH-terminal positions. Both of the synthetic peptides were found to decrease tail-flick latency in rats, and the octapeptide was more active than the octadecapeptide. The octapeptide was found also to attenuate the prolongation of the tail-flick latency induced by morphine.