Protein tyrosine nitration increases in vivo as a result of oxidative stress and is elevated in numerous inflammatory-associated diseases. Mammalian fructose-1,6-bisphosphate aldolases are tyrosine nitrated in lung epithelial cells and liver, as well as in retina under different inflammatory conditions. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, we now show that aldolase A is nitrated in human skin fibroblasts. To reveal the consequences of tyrosine nitration, we studied the impact of peroxynitrite on the glycolytic functions of aldolase A. A peroxynitrite concentration-dependent decrease in fructose-1,6-bisphosphate cleavage activity was observed with a concomitant increase in nitrotyrosine immunoreactivity. Both Vmax and the Km for fructose-1,6-bisphosphate decreased after incubation with peroxynitrite. Aldolase nitrotyrosine immunoreactivity diminished following carboxypeptidase Y digestion, demonstrating that tyrosine residues in the carboxyl-terminal region of aldolase are major targets of nitration. Aldolase A contains a carboxyl-terminal tyrosine residue, Tyr363, that is critical for its catalytic activity. Indeed, tandem mass spectrometric analysis of trypsin-digested aldolase showed that Tyr363 is the most susceptible to nitration, with a modification of Tyr342 occurring only after nitration of Tyr363. These tyrosine nitrations likely result in altered interactions between the carboxyl-terminal region and enzyme substrate or reaction intermediates causing the decline in activity. The results suggest that tyrosine nitration of aldolase A can contribute to an impaired cellular glycolytic activity. © 2004 by The American Society for Biochemistry and Molecular Biology, Inc.
CITATION STYLE
Koeck, T., Levison, B., Hazen, S. L., Crabb, J. W., Stuehr, D. J., & Aulak, K. S. (2004). Tyrosine nitration impairs mammalian aldolase A activity. Molecular and Cellular Proteomics, 3(6), 548–557. https://doi.org/10.1074/mcp.M300141-MCP200
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