{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,20]],"date-time":"2025-10-20T10:19:25Z","timestamp":1760955565833},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"2","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1984,6,1]]},"abstract":"<jats:p>The kinetics of inhibition of dopamine (3,4-dihydroxyphenethylamine) beta-mono-oxygenase by cyanide (CN-) and azide (N3-) ions have been investigated by using steady-state methods. Both anions show complex non-competitive-inhibition patterns with respect to ascorbate, suggestive of anion binding at two different sites on the oxidized enzyme. To further investigate this finding, e.p.r. titrations of CN- and N3- binding to the 63Cu-reconstituted enzyme were carried out. Addition of approx. 2 equiv. of CN- to copper elicits a new signal with g = 2.217, g = 2.025, A = 17.0 mT characteristic of a copper (II)-cyano complex. Simulations show that this signal accounts for half the copper (II) in the enzyme. The remainder of the enzyme-bound copper is expressed by a signal close to, but not identical with, that of native enzyme. Further addition of CN- induces a simultaneous decrease in intensity of both of these signals so that their 1:1 ratio is maintained. Binding of N3-, on the other hand, changes the e.p.r. spectrum to a form different from either that of the native or CN\u2012 -treated enzyme, and integrates to 100% of the copper in the enzyme (g = 2.252, g = 2.050, A = 16.5 mT). Resolved superhyperfine structure is apparent in the g region. N3- binding is also accompanied by the appearance of a broad charge-transfer band centred at 387 nm. Neither 9 nor 35 GHz e.p.r. spectra show evidence for more than one (non-interacting) species of Cu(II) in native enzyme and N3- derivatives. The binding and reactivity of CN-, on the other hand, argues against independent copper sites in the enzyme.<\/jats:p>","DOI":"10.1042\/bj2200447","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T20:42:06Z","timestamp":1439239326000},"page":"447-454","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Kinetic and e.p.r. studies of cyanide and azide binding to the copper sites of dopamine (3,4-dihydroxyphenethylamine) \u03b2-mono-oxygenase"],"prefix":"10.1042","volume":"220","author":[{"given":"N J","family":"Blackburn","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D","family":"Collison","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J","family":"Sutton","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"F E","family":"Mabbs","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\/220\/2\/447\/581183\/bj2200447.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/220\/2\/447\/581183\/bj2200447.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T13:38:47Z","timestamp":1637847527000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/220\/2\/447\/15748\/Kinetic-and-e-p-r-studies-of-cyanide-and-azide"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,6,1]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1984,6,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2200447","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1984,6,1]]}}}