{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T07:57:07Z","timestamp":1770969427771,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"2","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1992,9,1]]},"abstract":"<jats:p>Angiotensin-converting enzyme (ACE) was isolated from detergent-derived extracts of human intestinal brush-border membranes (BBMs) by immunoprecipitation using a monoclonal antibody. Analysis of the immunoprecipitates by SDS\/PAGE revealed a polypeptide of apparent M(r) 184,000 under reducing and non-reducing conditions, indicating that ACE does not contain intermolecular disulphide bridges. The quaternary structure of ACE was examined using cross-linking experiments with dithiobis[succinimidylpropionate] (DSP) and density gradient centrifugation on sucrose gradients. Both approaches demonstrated that ACE is assembled in the membrane as a monomer. By contrast, the control glycoprotein aminopeptidase N (ApN) exists as a dimer. Biosynthetic labelling experiments in intestinal tissue explants demonstrated that the 184,000-M(r) protein is generated from a single-polypeptide, mannose-rich precursor of ACE (M(r) 175,000) by modification of the carbohydrate side-chains in the Golgi apparatus. The mode of association of the mature form of the enzyme with BBMs was investigated by hydrophobic labelling of right-side-out brush-border vesicles with the photoactivatable carbene-generating reagent 125I-labelled 3-(trifluoromethyl)-3-(m[formylamino]phenyl)diazirine (125I-labelled TID), followed by treatment with trypsin at dilutions that do not cause substantial degradation of ACE. These studies demonstrated that ACE is associated with the membrane via a hydrophobic segment. Furthermore, treatment of 35S-labelled inside-out membrane vesicles with trypsin revealed that ACE possesses a cytoplasmic tail, and therefore has a transmembraneous orientation.<\/jats:p>","DOI":"10.1042\/bj2860451","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:28:42Z","timestamp":1439242122000},"page":"451-457","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Angiotensin-converting enzyme of the human small intestine. Subunit and quaternary structure, biosynthesis and membrane association"],"prefix":"10.1042","volume":"286","author":[{"given":"H Y","family":"Naim","sequence":"first","affiliation":[{"name":"Institute of Microbiology, Heinrich-Heine University of D\u00fcsseldorf, Universit\u00e4tsstrasse 1, D-4000 D\u00fcsseldorf 1, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/286\/2\/451\/608775\/bj2860451.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/286\/2\/451\/608775\/bj2860451.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,23]],"date-time":"2021-11-23T21:56:38Z","timestamp":1637704598000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/286\/2\/451\/28134\/Angiotensin-converting-enzyme-of-the-human-small"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,9,1]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1992,9,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2860451","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,9,1]]}}}