beta-Endorphin: structure-activity relationships in the guinea pig ileum and opiate receptor binding assays. |
| |
Authors: | B A Doneen D Chung D Yamashiro P Y Law H H Loh C H Li |
| |
Affiliation: | 1. Hormone Research Laboratory, University of California, San Francisco, California 94143 USA;1. Department of Pharmacology, University of California, San Francisco, California 94143 USA |
| |
Abstract: | The opiate activities of some derivatives and enzymatic digests of camel and human β-endorphin were determined in the guinea pig ileum and rat brain opiate receptor binding assays. Derivatives of β-endorphins altered within the amino-terminal five residues showed pronounced losses in activity. Anisylation of the C-terminal glutamic acid residue of βh-endorphin produced only small reductions in activity. Chymotryptic digestion greatly weakened the opiate activities of βh-endorphin, whereas carboxypeptidase A, tryptic and leucine aminopeptidase digests showed only small losses in potency. The C-terminus of β-endorphin appears to contribute little directly to opiate activity. Amino acid analysis and assay of the leucine aminopeptidase digests suggest that the larger potency of β-endorphin relative to Met-enkephalin may be a consequence of its greater resistance to exopeptidase attack. |
| |
Keywords: | Met-enkephalin methionine enkephalin camel β-endorphin human β-endorphin camel β-melanotropin sheep β-lipotropin that peptide corresponding to residues, (61–65),-(61–76), etc., of the sequence of β-lipotropin |
本文献已被 ScienceDirect 等数据库收录! |
|