Watkinson A, Dockray G J, Young J, Gregory H
Physiological Laboratory, University of Liverpool, U.K.
Biochim Biophys Acta. 1988 Jul 20;955(2):231-5. doi: 10.1016/0167-4838(88)90197-5.
Proenkephalin A-derived peptides are known to occur in the gut, but their precise identity is uncertain. We report here the isolation of N-terminally extended forms of Met-enkephalin Arg6Gly7Leu8 from porcine upper digestive tract monitored by radioimmunoassay. A single major form was identified in pyloric antral muscle and mucosa, but in the duodenum two major forms were detected. Microsequence analysis together with immunological data revealed that the antral mucosal peptide and the most acidic duodenal peptide had identical amino-acid sequences, corresponding to a 5.3 kDa peptide terminating in Met-enkephalin Arg6Gly7Leu8. The data indicate that high-molecular-weight peptides may constitute a major proportion of gut opioid peptide immunoactivity.
已知脑啡肽原A衍生肽存在于肠道中，但其确切性质尚不确定。我们在此报告通过放射免疫分析监测从猪上消化道分离出的N端延伸形式的甲硫氨酸脑啡肽-精氨酸6-甘氨酸7-亮氨酸8。在幽门窦肌肉和黏膜中鉴定出一种主要形式，但在十二指肠中检测到两种主要形式。微序列分析和免疫学数据表明，窦黏膜肽和最酸性的十二指肠肽具有相同的氨基酸序列，对应于一种以甲硫氨酸脑啡肽-精氨酸6-甘氨酸7-亮氨酸8结尾的5.3 kDa肽。数据表明，高分子量肽可能构成肠道阿片肽免疫活性的主要部分。
