{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T15:21:04Z","timestamp":1778858464506,"version":"3.51.4"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"1","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1975,4,1]]},"abstract":"<jats:p>In stopped-flow experiments in which oxidized cytochrome c oxidase was mixed with ferrocytochrome c in the presence of a range of oxygen concentrations and in the absence and presence of cyanide, a fast phase, reflecting a rapid approach to an equilibrium, was observed. Within this phase, one or two molecules of ferrocytochrome were oxidized per haem group of cytochrome a, depending on the concentration of ferrocytochrome c used. The reasons for this are discussed in terms of a mechanism in which all electrons enter through cytochrome a, which, in turn, is in rapid equilibrium with a second site, identified with \u2018visible\u2019 copper (830 nm-absorbing) Cud (Beinert et al., 1971). The value of the bimolecular rate constant for the reaction between cytochromes c2+ and a3+ was between 10(6) and 10(7) M(-1)-S(-1); some variability from preparation to preparation was observed. At high ferrocytochrome c concentrations, the initial reaction of cytochrome c2+ with cytochrome a3+ could be isolated from the reaction involving the \u2018visible\u2019 copper and the stoicheiometry was found to approach one molecule of cytochrome c2+ oxidized for each molecule of cytochrome a3+ reduced. At low ferrocytochrome c concentrations, however, both sites (i.e. cytochrome a and Cud) were reduced simultaneously and the stoicheiometry of the initial reaction was closer to two molecules of cytochrome c2+ oxidized per molecule of cytochrome a reduced. The bleaching of the 830 nm band lagged behind or was simultaneous with the formation of the 605 nm band and does not depend on the cytochrome c concentration, whereas the extinction at the steady-state does. The time-course of the return of the 830 nm-absorbing species is much faster than the bleaching of the 605 nm-absorbing component, and parallels that of the turnover phase of cytochrome c2+ oxidation. Additions of cyanide to the oxidase preparations had no effect on the observed stoicheiometry or kinetics of the reduction of cytochrome a and \u2018visible\u2019 copper, but inhibited electron transfer to the other two sites, cytochrome a3 and the undetectable copper, Cuu.<\/jats:p>","DOI":"10.1042\/bj1470145","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T19:57:34Z","timestamp":1439236654000},"page":"145-153","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":71,"title":["Kinetic studies on the reaction between cytochrome c oxidase and ferrocytochrome c"],"prefix":"10.1042","volume":"147","author":[{"given":"M T","family":"Wilson","sequence":"first","affiliation":[{"name":"School of Biological Sciences, University of East Anglia, Norwich NOR 88C, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C","family":"Greenwood","sequence":"additional","affiliation":[{"name":"School of Biological Sciences, University of East Anglia, Norwich NOR 88C, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"Brunori","sequence":"additional","affiliation":[{"name":"Centro di Biologica Molecolare del C.N.R., Istituto di Chimica Biologica, Universit\u00e0 di Roma, 1-00185 Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E","family":"Antonini","sequence":"additional","affiliation":[{"name":"Centro di Biologica Molecolare del C.N.R., Istituto di Chimica Biologica, Universit\u00e0 di Roma, 1-00185 Roma, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/147\/1\/145\/563761\/bj1470145.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/147\/1\/145\/563761\/bj1470145.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,26]],"date-time":"2021-11-26T16:20:06Z","timestamp":1637943606000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/147\/1\/145\/9478\/Kinetic-studies-on-the-reaction-between-cytochrome"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1975,4,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1975,4,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj1470145","relation":{},"ISSN":["0264-6021"],"issn-type":[{"value":"0264-6021","type":"print"}],"subject":[],"published":{"date-parts":[[1975,4,1]]}}}