Oxidative stress related post-translational modifications in HIV infected postmortem brain tissue

摘要

Analysis of the HIV-infected brain tryptic peptides pulled down with nitrotyrosine-antibody did not lead to the identification of any nitrated peptides. However, many oxidized peptides were identified with high confidence. Peroxynitrite treatment of model protein beta-tubulin lead to multiple modifications on the protein including nitration of Tyr and Trp, and multiple oxidized forms of Cys, Met, Trp, Tyr, and His. Immunoprecipitation with nitrotyrosine antibody-protein G-agarose conjugate and protein A/G-agarose (control) of peroxynitrite treated beta-tubulin tryptic peptides indicate that nitrotyrosine antibody is capable of binding to oxidized peptides as well as nitrated peptides. Formylkynurenin containing beta-tubulin peptide was detected in both peroxynitrite treated beta-tubulin and HIV brain lysate.