title: Endogenously nitrated proteins in mouse brain: links to neurodegenerative disease.
abstract: Increased abundance of nitrotyrosine modifications of proteins have been documented in multiple pathologies in a variety of tissue types and play a role in the redox regulation of normal metabolism. To identify proteins sensitive to nitrating conditions in vivo, a comprehensive proteomic data set identifying 7792 proteins from a whole mouse brain, generated by LC/LC-MS/MS analyses, was used to identify nitrated proteins. This analysis resulted in the identification of 31 unique nitrotyrosine sites within 29 different proteins. More than half of the nitrated proteins that have been identified are involved in Parkinson's disease, Alzheimer's disease, or other neurodegenerative disorders. Similarly, nitrotyrosine immunoblots of whole brain homogenates show that treatment of mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), an experimental model of Parkinson's disease, induces an increased level of nitration of the same protein bands observed to be nitrated in brains of untreated animals. Comparing sequences and available high-resolution structures around nitrated tyrosines with those of unmodified sites indicates a preference of nitration in vivo for surface accessible tyrosines in loops, a characteristic consistent with peroxynitrite-induced tyrosine modification. In addition, most sequences contain cysteines or methionines proximal to nitrotyrosines, contrary to suggestions that these amino acid side chains prevent tyrosine nitration. More striking is the presence of a positively charged moiety near the sites of nitration, which is not observed for non-nitrated tyrosines. Together, these observations suggest a predictive tool of functionally important sites of nitration and that cellular nitrating conditions play a role in neurodegenerative changes in the brain.
authors.affiliation: Cell Biology and Biochemistry Group, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
authors.forename: Colette A
authors.initials: CA
authors.lastname: Sacksteder
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Qian
authors.forename: Tatyana V
authors.initials: TV
authors.lastname: Knyushko
authors.forename: Haixing
authors.initials: H
authors.lastname: Wang
authors.forename: Mark H
authors.initials: MH
authors.lastname: Chin
authors.forename: Goran
authors.initials: G
authors.lastname: Lacan
authors.forename: William P
authors.initials: WP
authors.lastname: Melega
authors.forename: David G
authors.initials: DG
authors.lastname: Camp
authors.forename: Richard D
authors.initials: RD
authors.lastname: Smith
authors.forename: Desmond J
authors.initials: DJ
authors.lastname: Smith
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Squier
authors.forename: Diana J
authors.initials: DJ
authors.lastname: Bigelow
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002197:Capillary Action; D002853:Chromatography, Liquid; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D019636:Neurodegenerative Diseases / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism; D010446:Peptide Fragments; D011487:Protein Conformation; D020543:Proteome
chemical_list: D009419:Nerve Tissue Proteins; D009566:Nitrates; D010446:Peptide Fragments; D020543:Proteome; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine