Bunnett N W, Turner A J, Hryszko J, Kobayashi R, Walsh J H
University of Washington, Department of Surgery, Seattle.
Gastroenterology. 1988 Oct;95(4):952-7. doi: 10.1016/0016-5085(88)90168-0.
The purpose of this investigation was to isolate the cell-surface enzyme endopeptidase-24.11 from the stomach wall of the pig and to examine the hydrolysis of the gastric neuropeptides. Endopeptidase-24.11 was isolated from gastric membranes by immunoadsorbent chromatography using a monoclonal antibody to porcine kidney endopeptidase-24.11. The enzyme was purified with a yield of 1.2 micrograms/g wet wt of fundic muscle. A single polypeptide chain of apparent subunit molecular weight of 90,000 was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gastric endopeptidase-24.11 hydrolyzed substance P, gastrin-releasing peptide 10, [Leu5] enkephalin, and [Met5] enkephalin by cleavage of peptide bonds on the N-terminal side of hydrophobic amino acids. The enzymatic activity was inhibited completely by phosphoramidon (10(-6) M) and strongly by 1,10-phenanthroline (10(-3) M), but was unaffected by captopril (10(-5) M).
本研究的目的是从猪的胃壁中分离细胞表面酶内肽酶-24.11，并检测胃神经肽的水解情况。使用针对猪肾内肽酶-24.11的单克隆抗体，通过免疫吸附色谱法从胃膜中分离出内肽酶-24.11。该酶经纯化后，每克胃底肌湿重的产量为1.2微克。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳鉴定出一条表观亚基分子量为90,000的单多肽链。胃内肽酶-24.11通过切割疏水性氨基酸N端侧的肽键来水解P物质、胃泌素释放肽10、[亮氨酸5]脑啡肽和[甲硫氨酸5]脑啡肽。磷酰胺（10(-6) M）可完全抑制该酶活性，1,10-菲咯啉（10(-3) M）可强烈抑制，而卡托普利（10(-5) M）对其活性无影响。
