{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T19:59:50Z","timestamp":1760299190509},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"2","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1989,10,15]]},"abstract":"<jats:p>U.v.-visible-absorption and e.p.r. spectroscopy were used to study the type 2 and type 3 copper centres in the mercury derivative of laccase. After treatment with peroxide the mercury derivative of laccase exhibits a fully developed absorption band at 330 nm (delta epsilon = 2900 +\/- 100 M-1.cm-1, which is characteristic of type 3 copper in the oxidized state. In addition, there is a weak ligand-field absorption at 740 nm (epsilon = 380 +\/- 30 M-1.cm-1), which can be assigned to the type 3 pair. Because the e.p.r. spectrum of the type 2 copper is well resolved in the case of the mercury derivative of laccase, for the first time we have been able to observe spectroscopic evidence for a pH-dependent structural transition that has been invoked to explain the kinetics of enzyme reduction [Andr\u00e9asson &amp; Reinhammar (1979) Biochim. Biophys. Acta 568, 145-156]. According to the e.p.r. data the pKa lies in the range 6-7, and comparisons with a model compound show that the spectral changes can plausibly be interpreted in terms of the deprotonation of a water molecule in the co-ordination sphere of the type 2 copper.<\/jats:p>","DOI":"10.1042\/bj2630425","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:14:21Z","timestamp":1439241261000},"page":"425-429","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Spectroscopic studies of the type 2 and type 3 copper centres in the mercury derivative of laccase"],"prefix":"10.1042","volume":"263","author":[{"given":"R","family":"Tamilarasan","sequence":"first","affiliation":[{"name":"Department of Chemistry, Purdue University, West Lafayette, IN 47907-3699, U.S.A."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D R","family":"McMillin","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Purdue University, West Lafayette, IN 47907-3699, U.S.A."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/263\/2\/425\/597904\/bj2630425.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/263\/2\/425\/597904\/bj2630425.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T18:09:51Z","timestamp":1637863791000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/263\/2\/425\/24593\/Spectroscopic-studies-of-the-type-2-and-type-3"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1989,10,15]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1989,10,15]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2630425","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1989,10,15]]}}}