Nitration transforms a sensitive peroxiredoxin 2 into a more active and robust peroxidase.
Peroxiredoxins (Prx) are efficient thiol-dependent peroxidases and key players in the mechanism of H2O2-induced redox signaling. Any structural change that could affect their redox state, oligomeric structure, and/or interaction with other proteins could have a significant impact on the cascade of signaling events. Several post-translational modifications have been reported to modulate Prx activity. One of these, overoxidation of the peroxidatic cysteine to the sulfinic derivative, inactivates the enzyme and has been proposed as a mechanism of H2O2 accumulation in redox signaling (the floodgate hypothesis). Nitration of Prx has been reported in vitro as well as in vivo; in particular, nitrated Prx2 was identified in brains of Alzheimer disease patients. In this work we characterize Prx2 tyrosine nitration, a post-translational modification on a noncatalytic residue that increases its peroxidase activity and its resistance to overoxidation. Mass spectrometry analysis revealed that treatment of disulfide-oxidized Prx2 with excess peroxynitrite renders mainly mononitrated and dinitrated species. Tyrosine 193 of the YF motif at the C terminus, associated with the susceptibility toward overoxidation of eukaryotic Prx, was identified as nitrated and is most likely responsible for the protection of the peroxidatic cysteine against oxidative inactivation. Kinetic analyses suggest that tyrosine nitration facilitates the intermolecular disulfide formation, transforming a sensitive Prx into a robust one. Thus, tyrosine nitration appears as another mechanism to modulate these enzymes in the complex network of redox signaling.
From the Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay, the Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo 11100, Uruguay.
Lía M
LM
Randall
From the Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay, the Laboratorio de Biología Redox de Tripanosomas, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay.
Bruno
B
Manta
the Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo 11100, Uruguay, the Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, 11100 Montevideo, Uruguay.
Martín
M
Hugo
the Unidad de Bioquímica y Proteómica Analíticas, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay, the Unidad de Bioquímica y Proteómica Analíticas, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, 11600 Montevideo, Uruguay, and.
Magdalena
M
Gil
the Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo 11100, Uruguay, the Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, 11100 Montevideo, Uruguay, the Unidad de Bioquímica y Proteómica Analíticas, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay.
Carlos
C
Batthyàny
the Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo 11100, Uruguay, the Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, 11100 Montevideo, Uruguay.
Madia
M
Trujillo
the Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157.
Leslie B
LB
Poole
From the Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay, the Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo 11100, Uruguay, denicola@fcien.edu.uy.
Ana
A
Denicola
D000818:Animals; D020134:Catalytic Domain; D048209:Echinococcus granulosus / Q000201:enzymology; D004789:Enzyme Activation / Q000502:physiology; D004912:Erythrocytes / Q000201:enzymology*; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology*; D030421:Peroxynitrous Acid / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000502:physiology; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013879:Thioredoxins / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
D029968:Escherichia coli Proteins; D018398:Homeodomain Proteins; C512693:PRRX2 protein, human; D011994:Recombinant Proteins; D030421:Peroxynitrous Acid; D014443:Tyrosine; D013879:Thioredoxins; D006861:Hydrogen Peroxide; D009584:Nitrogen
Hydrogen Peroxide; Overoxidation; Oxidative Stress; Peroxiredoxin; Peroxynitrite; Post-translational Modification; Redox Signaling; Tyrosine Nitration