{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,21]],"date-time":"2025-10-21T14:51:28Z","timestamp":1761058288013},"reference-count":10,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2004,2,9]],"date-time":"2004-02-09T00:00:00Z","timestamp":1076284800000},"content-version":"vor","delay-in-days":3326,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biospectroscopy"],"published-print":{"date-parts":[[1995,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The Raman bands associated with different rotamers of hexadienoyl ethyl thiolester, CH<jats:sub>3<\/jats:sub>\uf8ffCH\uf8feCH\uf8ffCH\uf8feCH\uf8ffC(\uf8feO)\uf8ffS\uf8ffCH<jats:sub>2<\/jats:sub>\uf8ffCH<jats:sub>3<\/jats:sub>, have been partially assigned using recent conformational and vibrational spectroscopic analyses of ethyl thiocrotonate CH<jats:sub>3<\/jats:sub>\uf8ffCH\uf8feCH\uf8ffC(\uf8feO)\uf8ffS\uf8ffCH<jats:sub>2<\/jats:sub>\uf8ffCH<jats:sub>3<\/jats:sub>.<jats:sup>1<\/jats:sup> In particular, rotational isomers involving the \uf8feCH\uf8ffC(\uf8feO) and \uf8ffS\uf8ffCH<jats:sub>2<\/jats:sub>\uf8ff axes have been characterized. The assignment of the vibrational modes of different conformers of hexadienoyl ethyl thiolester was further facilitated by variable\u2010temperature (+20\u00b0C to \u221290\u00b0C) Raman studies on the neat thiolester. High\u2010quality Raman spectra of hexadienoyl\u2010coenzyme A bound to the enzyme enoyl\u2010CoA hydratase were obtained using 647.1\u2010nm excitation and Raman difference spectroscopy. The findings provided by analysis of the ethyl thiolester model compound enable us to conclude that conformational selection occurs for the CoA analog upon binding, resulting in the presence of a single\u2010rotamer population in the hexadienoyl moiety on the enzyme. The hexadienoyl\u2010CoA was labeled with <jats:sup>18<\/jats:sup>O in the C\uf8feO group and, separately, with <jats:sup>13<\/jats:sup>C at the C2 position. A comparison of Raman data for the free and bound ligands, isotopically labeled and unlabeled, indicates that strong \u03c0\u2010electron polarization occurs in only a part of the hexadienoyl chain, viz, in the C\uf8feC\uf8ffC\uf8feO fragment, upon binding. The polarization gives rise to important contributions from canonical (resonance) forms of the type \uf8ffC<jats:sup>+<\/jats:sup>\uf8ffC\uf8feC\uf8ffO<jats:sup>\u2212<\/jats:sup>. In contrast, the C4\uf8feC5 linkage (where the carbon atom numbering is C6\uf8ffC5\uf8feC4\uf8ffC3\uf8feC2\uf8ffC1\uf8feO) seems little perturbed in the bound ligand. The causes and mechanistic advantage of the observed localized polarization are discussed. \u00a9 1995 John Wiley &amp; Sons, Inc.<\/jats:p>","DOI":"10.1002\/bspy.350010604","type":"journal-article","created":{"date-parts":[[2005,5,27]],"date-time":"2005-05-27T23:49:41Z","timestamp":1117237781000},"page":"387-394","source":"Crossref","is-referenced-by-count":14,"title":["Localized electron polarization in a substrate analog binding to the active site of enoyl\u2010CoA hydratase: Raman spectroscopic and conformational analyses of rotamers of hexadienoyl thiolesters"],"prefix":"10.1002","volume":"1","author":[{"given":"P. J.","family":"Tonge","sequence":"first","affiliation":[]},{"given":"V. E.","family":"Anderson","sequence":"additional","affiliation":[]},{"given":"R.","family":"Fausto","sequence":"additional","affiliation":[]},{"given":"M.","family":"Kim","sequence":"additional","affiliation":[]},{"given":"M.","family":"Pusztai\u2010Carey","sequence":"additional","affiliation":[]},{"given":"P. R.","family":"Carey","sequence":"additional","affiliation":[]}],"member":"311","published-online":{"date-parts":[[2004,2,9]]},"reference":[{"key":"e_1_2_1_2_2","doi-asserted-by":"publisher","DOI":"10.1039\/ft9949003491"},{"key":"e_1_2_1_3_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1432-1033.1975.tb04134.x"},{"key":"e_1_2_1_4_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00238a013"},{"key":"e_1_2_1_5_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00208a014"},{"key":"e_1_2_1_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)63508-2"},{"key":"e_1_2_1_7_2","doi-asserted-by":"publisher","DOI":"10.1366\/0003702934066145"},{"key":"e_1_2_1_8_2","doi-asserted-by":"publisher","DOI":"10.1366\/000370270774371778"},{"key":"e_1_2_1_9_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.bb.13.060184.000325"},{"key":"e_1_2_1_10_2","first-page":"1","volume-title":"Biomolecular Spectroscopy, Part A","author":"Siebert F.","year":"1993"},{"key":"e_1_2_1_11_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.bb.20.060191.002423"}],"container-title":["Biospectroscopy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fbspy.350010604","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/bspy.350010604","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,26]],"date-time":"2023-10-26T03:01:10Z","timestamp":1698289270000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/bspy.350010604"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1995,1]]},"references-count":10,"journal-issue":{"issue":"6","published-print":{"date-parts":[[1995,1]]}},"alternative-id":["10.1002\/bspy.350010604"],"URL":"https:\/\/doi.org\/10.1002\/bspy.350010604","archive":["Portico"],"relation":{},"ISSN":["1075-4261","1520-6343"],"issn-type":[{"value":"1075-4261","type":"print"},{"value":"1520-6343","type":"electronic"}],"subject":[],"published":{"date-parts":[[1995,1]]}}}