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dc.contributor.authorPrütz, W A
dc.contributor.authorButler, John
dc.contributor.authorLand, Edward J
dc.date.accessioned2010-12-03T16:07:39Z
dc.date.available2010-12-03T16:07:39Z
dc.date.issued1985-02
dc.identifier.citationMethionyl----tyrosyl radical transitions initiated by Br2-. in peptide model systems and ribonuclease A. 1985, 47 (2):149-56 Int J Radiat Biol Relat Stud Phys Chem Meden
dc.identifier.issn0020-7616
dc.identifier.pmid3872270
dc.identifier.urihttp://hdl.handle.net/10541/117151
dc.description.abstractA series of radical transitions, Br2-.----Met(S therefore Br)----Trp(indolyl)----Tyr (phenoxyl), has been demonstrated by pulse radiolysis of N2O-saturated aqueous solutions containing Br-, Met-Gly and Trp-(Gly)2-Tyr at pH 6.7. The intramolecular Met(S therefore Br)----Trp(indolyl) transition in the dipeptide Met-Trp is shown to proceed via the Trp+. radical cation, with a rate constant of k approximately 10(7)s-1, consistent with an electron transfer. Br2-.-attack upon ribonuclease A (RNase) leads to a fast Met(S therefore Br)----Tyr(phenoxyl) process, k = (4.0 +/- 1.0) X 10(5)s-1, probably involving the solvent-exposed Met-29 and the adjacent Tyr-25. Phenoxyl dimerization in the RNase system produces the characteristic o,o'-biphenol fluorescence, but a competing interaction of the Tyr-25(phenoxyl) with the 26-84 disulphide group also appears possible.
dc.language.isoenen
dc.subject.meshBromine
dc.subject.meshElectron Transport
dc.subject.meshFree Radicals
dc.subject.meshMethionine
dc.subject.meshPeptides
dc.subject.meshPulse Radiolysis
dc.subject.meshRibonuclease, Pancreatic
dc.titleMethionyl----tyrosyl radical transitions initiated by Br2-. in peptide model systems and ribonuclease A.en
dc.typeArticleen
dc.contributor.departmentUniversitat Freiburg, Institut fur Biophysik und Strahlenbiologie, Albertstr. 23, D-7800 Freiburg, F.R. Germany.en
dc.identifier.journalInternational Journal of Radiation Biology and Related Studies in Physics, Chemistry, and Medicineen
html.description.abstractA series of radical transitions, Br2-.----Met(S therefore Br)----Trp(indolyl)----Tyr (phenoxyl), has been demonstrated by pulse radiolysis of N2O-saturated aqueous solutions containing Br-, Met-Gly and Trp-(Gly)2-Tyr at pH 6.7. The intramolecular Met(S therefore Br)----Trp(indolyl) transition in the dipeptide Met-Trp is shown to proceed via the Trp+. radical cation, with a rate constant of k approximately 10(7)s-1, consistent with an electron transfer. Br2-.-attack upon ribonuclease A (RNase) leads to a fast Met(S therefore Br)----Tyr(phenoxyl) process, k = (4.0 +/- 1.0) X 10(5)s-1, probably involving the solvent-exposed Met-29 and the adjacent Tyr-25. Phenoxyl dimerization in the RNase system produces the characteristic o,o'-biphenol fluorescence, but a competing interaction of the Tyr-25(phenoxyl) with the 26-84 disulphide group also appears possible.


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