期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1982
卷号:79
期号:6
页码:2096-2100
DOI:10.1073/pnas.79.6.2096
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:[Met]Enkephalin-containing proteins of 8600 and 12,600 daltons have been isolated from acid extracts of bovine adrenal medulla and purified to homogeneity, and their sequences have been determined by a combination of automated Edman degradation, tryptic mapping, and enzymatic time-course hydrolysis. The 8600-dalton protein contains one copy of the [Met]enkephalin sequence at the COOH terminus and the 12,600-dalton protein contains three copies of [Met]enkephalin, of which two are internal and the third 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. Furthermore, 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) [Jones et al. (1980) Arch. Biochem. Biophys. 204, 392-395]. All three 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.