{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T07:11:23Z","timestamp":1773299483268,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1988,11,1]]},"abstract":"<jats:p>The mitochondrial electron-transfer flavoprotein (ETF) is a heterodimer containing only one FAD. In previous work on the structure-function relationships of ETF, its interaction with the general acyl-CoA dehydrogenase (GAD) was studied by chemical cross-linking with heterobifunctional reagents [D. J. Steenkamp (1987) Biochem. J. 243, 519-524]. GAD whose lysine residues were substituted with 3-(2-pyridyldithio)propionyl groups was preferentially cross-linked to the small subunit of ETF, the lysine residues of which had been substituted with 4-mercaptobutyramidine (MBA) groups. This work was extended to the interaction of ETF with ETF-ubiquinone oxidoreductase (ETF-Q ox). ETF-Q ox was partially inactivated by modification with N-succinimidyl 3-(2-pyridyldithio)propionate to introduce pyridyl disulphide structures. A similar modification of ETF caused a large increase in the apparent Michaelis constant of ETF-Q ox for modified ETF owing to the loss of positive charge on some critical lysines of ETF. When ETF-Q ox was modified with 2-iminothiolane to introduce 4-mercaptobutyramidine groups, only a minor effect on the activity of the enzyme was observed. To retain the positive charges on the lysine residues of ETF, pyridyl disulphide structures were introduced by treating ETF with 2-iminothiolane in the presence of 2,2\u2032-dithiodipyridyl. The electron-transfer activity of the resultant ETF preparation containing 4-(2-pyridyldithio)butyramidine (PDBA) groups was only slightly affected. When ETF-Q ox substituted with MBA groups was mixed with ETF bearing PDBA groups, at least 70% of the cross-links formed between the two proteins were between the small subunit of ETF and ETF-Q ox. ETF-Q ox, therefore, interacts predominantly with the same subunit of ETF as GAD. Variables which affect the selectivity of ETF-Q ox cross-linking to the subunits of ETF are considered.<\/jats:p>","DOI":"10.1042\/bj2550869","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:12:33Z","timestamp":1439241153000},"page":"869-876","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Cross-linking of the electron-transfer flavoprotein to electron-transfer flavoprotein-ubiquinone oxidoreductase with heterobifunctional reagents"],"prefix":"10.1042","volume":"255","author":[{"given":"D J","family":"Steenkamp","sequence":"first","affiliation":[{"name":"Department of Chemical Pathology, University of Cape Town Medical School, Observatory 7925, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/255\/3\/869\/594283\/bj2550869.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/255\/3\/869\/594283\/bj2550869.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T18:07:24Z","timestamp":1637863644000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/255\/3\/869\/24391\/Cross-linking-of-the-electron-transfer"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1988,11,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1988,11,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2550869","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1988,11,1]]}}}