{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,19]],"date-time":"2025-09-19T10:48:00Z","timestamp":1758278880551},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1981,3,1]]},"abstract":"<jats:p>Optical. e.p.r. and near-infrared low-temperature m.c.d. (magnetic-circular-dichroism) spectroscopy were used to characterize the partially reduced cyanide-inhibited derivative of cytochrome c oxidase produced by anaerobic reductive titration with dithionite. The reductions of cytochrome a3+ and Cu2+a were followed by observation of the e.p.r. signals at g = 3.03, 2.21 and 1.5 and at g = 2.18, 2.03 and 1.99. As reduction proceeds new e.p.r. signals (g = 3.58 and 1.56) appear that quantify to give one haem per enzyme unit when a small excess of dithionite has been titrated in. The e.p.r. signal of the Cu2+a titrates in parallel with the disappearance of the band and 820nm in the optical absorption spectrum. The near-infrared m.c.d. spectrum shows the presence of the low-spin ferric haem, a3+, in the oxidized state of the enzyme, as a well-resolved positive peak at 1650nm. As reduction proceeds this band is replaced by one at 1550nm due to haem a3+(3)\u2013CN in the partially reduced state. Hence as haem a3+(3)\u2013CN becomes e.p.r.-detectable it also shows a near-infrared m.c.d. spectrum characteristic of a low-spin ferric haem. It is concluded that the partially reduced state of cyanide-inhibited cytochrome c oxidase contains a2+ . Cu+a . a3+(3)\u2013CN . Cu+a3.<\/jats:p>","DOI":"10.1042\/bj1930699","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T20:26:12Z","timestamp":1439238372000},"page":"699-708","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Characterization of the partially reduced cyanide-inhibited derivative of cytochrome <i>c<\/i> oxidase by optical, electron-paramagnetic-resonance and magnetic-circular-dichroism spectroscopy"],"prefix":"10.1042","volume":"193","author":[{"given":"M K","family":"Johnson","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D G","family":"Eglinton","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P E","family":"Gooding","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C","family":"Greenwood","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A J","family":"Thomson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/193\/3\/699\/564438\/bj1930699.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/193\/3\/699\/564438\/bj1930699.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T14:14:13Z","timestamp":1637849653000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/193\/3\/699\/17820\/Characterization-of-the-partially-reduced-cyanide"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1981,3,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1981,3,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj1930699","relation":{},"ISSN":["0264-6021"],"issn-type":[{"value":"0264-6021","type":"print"}],"subject":[],"published":{"date-parts":[[1981,3,1]]}}}