{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,20]],"date-time":"2025-08-20T12:47:15Z","timestamp":1755694035118},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"1","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1994,7,1]]},"abstract":"<jats:p>The thyroid plasma membrane contains a Ca(2+)-regulated NADPH-dependent H2O2-generating system which provides H2O2 for the peroxidase-catalysed biosynthesis of thyroid hormones. The electron transfer from NADPH to O2 catalysed by this system was studied by using diphenyleneiodonium (DPI), an inhibitor of flavo- and haemo-proteins. The prosthetic group of the H2O2 generator was removed by incubation with 5 mM CHAPS at 40 degrees C, and an active holoenzyme was reconstituted with FAD, but not with FMN. The H2O2-generating system also had an intrinsic Ca(2+)-dependent NADPH:ferricyanide reductase activity which is probably linked to its flavodehydrogenase component (or domain). Both activities, H2O2 production and ferricyanide reductase activity, were inhibited by DPI, with similar K1\/2 (2.5 nmol\/mg of protein). DPI only inhibited a system reduced with NADPH in the presence of Ca2+. NADPH could not be replaced by NADP+, NADH or sodium dithionite, suggesting the need for specific mild reduction of a redox centre in a particular conformation. Ferricyanide protected both activities against inhibition by DPI; the NADPH:ferricyanide reductase activity was completely protected at a ferricyanide concentration 20 times lower than that needed to protect the H2O2 formation, implying at least two target sites for DPI. One might be the flavodehydrogenase component; the other was beyond, on the entity which transfers the electrons to O2. This second site has not been identified.<\/jats:p>","DOI":"10.1042\/bj3010075","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:38:33Z","timestamp":1439242713000},"page":"75-81","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["The Ca2+\/NADPH-dependent H2O2 generator in thyroid plasma membrane: inhibition by diphenyleneiodonium"],"prefix":"10.1042","volume":"301","author":[{"given":"D","family":"D\u00e8me","sequence":"first","affiliation":[{"name":"INSERM U. 96, 80 rue du General Leclerc, Le Kremlin-Bicetre, 94276 Cedex, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J","family":"Doussiere","sequence":"additional","affiliation":[{"name":"Laboratoire de Biochimie, Departement de Biologie Mol6culaire et Structurale, Centre d'Etudes Nucl6aires, 38041 Grenoble Cedex, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"V","family":"De Sandro","sequence":"additional","affiliation":[{"name":"INSERM U. 96, 80 rue du General Leclerc, Le Kremlin-Bicetre, 94276 Cedex, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C","family":"Dupuy","sequence":"additional","affiliation":[{"name":"INSERM U. 96, 80 rue du General Leclerc, Le Kremlin-Bicetre, 94276 Cedex, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J","family":"Pommier","sequence":"additional","affiliation":[{"name":"INSERM U. 96, 80 rue du General Leclerc, Le Kremlin-Bicetre, 94276 Cedex, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A","family":"Virion","sequence":"additional","affiliation":[{"name":"INSERM U. 96, 80 rue du General Leclerc, Le Kremlin-Bicetre, 94276 Cedex, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/301\/1\/75\/614099\/bj3010075.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/301\/1\/75\/614099\/bj3010075.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,23]],"date-time":"2021-11-23T23:00:46Z","timestamp":1637708446000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/301\/1\/75\/30913\/The-Ca2-NADPH-dependent-H2O2-generator-in-thyroid"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,7,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1994,7,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj3010075","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,7,1]]}}}