Adrenal opioid proteins of 8600 and 12,600 daltons: intermediates in proenkephalin processing.

Publisher Website
Google Scholar
Abstract
[Met]Enkephalin-containing proteins of 8600 and 12,600 daltons were isolated from acid extracts of bovine adrenal medulla and purified to homogeneity, and their sequences were determined by a combination of automated Edman degradation, tryptic mapping and enzymatic time-course hydrolysis. The 8600-dalton protein contains 1 copy of the [Met]enkephalin sequence at the COOH terminus and the 12,600-dalton protein contains 3 copies of [Met]enkephalin, of which 2 are internal and the 3rd is at the COOH terminus. They possess identical NH2-terminal amino acid sequences, suggesting that the 8600-dalton protein is derived from the 12,600-dalton protein by intracellular proteolytic processing. This is supported by results from tryptic maps of both proteins. Chemical analysis of the tryptic peptides obtained from the 12,600-dalton protein indicates that it also contains the amino acid sequence that corresponds to a previously characterized enkephalin-containing polypeptide of 3800 daltons (peptide F). All 3 polypeptides appear to be intermediates in posttranslational processing of a still larger polyenkephalin precursor molecule, proenkephalin, and part of a biosynthetic pathway leading to smaller enkephalin-containing polypeptides and free enkephalins.

This publication has 27 references indexed in Scilit: