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dc.contributor.authorPrütz, W Aen
dc.contributor.authorButler, Johnen
dc.contributor.authorLand, Edward Jen
dc.date.accessioned2014-12-22T15:32:41Z
dc.date.available2014-12-22T15:32:41Z
dc.date.issued1983-08
dc.identifier.citationPhenol coupling initiated by one-electron oxidation of tyrosine units in peptides and histone. 1983, 44 (2):183-96 Int J Radiat Biol Relat Stud Phys Chem Meden
dc.identifier.issn0020-7616
dc.identifier.pmid6603438
dc.identifier.urihttp://hdl.handle.net/10541/337547
dc.description.abstractPhenoxyl radicals generated pulse radiolytically by the reaction of N.3 with Gly-Tyr decay biomolecularly (2k = 4.7 X 10(8)M-1 s-1) with efficient formation of 2,2'-dimers, which enolize rapidly (k = 2.7 X 10(4) s-1) to produce the 2,2'-biphenolic product. The build-up of the characteristic 2,2'-biphenol fluorescence (400 nm) and absorption also indicated a delayed (k = 80 s-1) process, probably involving the phenoxyl <-> phenoxy-quinol equilibrium. About 60 per cent of the Gly-Tyr phenoxyls were found to dimerize to the 2,2'-biphenol, and a similarly efficient 2,2'-coupling seems to occur with other tyrosyls, such as Lys-Tyr-Lys and histone. gamma-Radiolysis was applied to estimate relative yields of formation of 2,2'-biphenols under various conditions. Dimerization is almost completely inhibited by cysteine or oxygen, consistent with phenoxyl 'repair' by cysteine or O-.2; disproportionation of O-.2 with SOD prevents repair. The phenol 2,2'-coupling is less efficient for .OH- and inefficient for e-aq-initiation.
dc.language.isoenen
dc.rightsArchived with thanks to International journal of radiation biology and related studies in physics, chemistry, and medicineen
dc.subject.meshDipeptides
dc.subject.meshDose-Response Relationship, Radiation
dc.subject.meshGamma Rays
dc.subject.meshHistones
dc.subject.meshOxidation-Reduction
dc.subject.meshPhenols
dc.subject.meshPulse Radiolysis
dc.titlePhenol coupling initiated by one-electron oxidation of tyrosine units in peptides and histone.en
dc.typeArticleen
dc.contributor.departmentUniversitat Freiburg, Institut fur Biophysik und Strahlenbiologie, ALbertstrasse 23, D-7800 Freiburg, FR Germanyen
dc.identifier.journalInternational Journal of Radiation Biology and Related Studies in Physics, Chemistry, and Medicineen
html.description.abstractPhenoxyl radicals generated pulse radiolytically by the reaction of N.3 with Gly-Tyr decay biomolecularly (2k = 4.7 X 10(8)M-1 s-1) with efficient formation of 2,2'-dimers, which enolize rapidly (k = 2.7 X 10(4) s-1) to produce the 2,2'-biphenolic product. The build-up of the characteristic 2,2'-biphenol fluorescence (400 nm) and absorption also indicated a delayed (k = 80 s-1) process, probably involving the phenoxyl <-> phenoxy-quinol equilibrium. About 60 per cent of the Gly-Tyr phenoxyls were found to dimerize to the 2,2'-biphenol, and a similarly efficient 2,2'-coupling seems to occur with other tyrosyls, such as Lys-Tyr-Lys and histone. gamma-Radiolysis was applied to estimate relative yields of formation of 2,2'-biphenols under various conditions. Dimerization is almost completely inhibited by cysteine or oxygen, consistent with phenoxyl 'repair' by cysteine or O-.2; disproportionation of O-.2 with SOD prevents repair. The phenol 2,2'-coupling is less efficient for .OH- and inefficient for e-aq-initiation.


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