Sharov, Victor S.Galeva, Nadezhda A.Dremina, Elena S.Williams, Todd D.Schoneich, Christian2017-01-182017-01-182008-12-27Sharov, Victor S., Nadezhda A. Galeva, Elena S. Dremina, Todd D. Williams, and Christian Schöneich. "Inactivation of Rabbit Muscle Glycogen Phosphorylase B by Peroxynitrite Revisited: Does the Nitration of Tyr613 in the Allosteric Inhibition Site Control Enzymatic Function?" Archives of Biochemistry and Biophysics 484.2 (2009): 155-66.https://hdl.handle.net/1808/22642There is increasing evidence that sequence-specific formation of 3-nitrotyrosine (3-NT) may cause functional changes in target proteins. Recently, the nitration of Tyr residues in glycogen phosphorylase b (Ph-b) was implicated in the age-associated decline of protein function (Sharov et al., Exp. Gerontol. 41, 407–416; 2006); in another report, the nitration of one specific residue, Tyr613, located in the allosteric inhibition site was hypothesized as a rationale for peroxynitrite inactivation (Dairou et al., J. Mol. Biol. 372, 1009–1021; 2007). In the present study, we have optimized the analysis of in-gel Ph-b digests by high performance liquid chromatography-electro spray ionization-tandem mass spectrometry, in order to achieve a quantitative analysis of nitration of individual Tyr residues at a high coverage of Tyr-containing sequences (92%). Our data do not confirm the role of Tyr613 nitration in the control of enzymatic function. Furthermore, we show here that the enzymatic activity of Ph-b does not directly correlate with the protein nitration levels, and that the modification of Cys and, potentially, other amino acid residues can better rationalize Ph-b inactivation by peroxynitrite.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License 3.0 (CC BY-NC-ND 3.0 US), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.http://creativecommons.org/licenses/by-nc-nd/3.0/Glycogen phosphorylase bEnzymatic activityTryosine nitrationCysteine oxidationPeroxynitriteMass spectrometrySolvent accessible surface areaArticle10.1016/j.abb.2008.12.012openAccess