Proteomic analysis of nitrated and 4-hydroxy-2-nonenal-modified serum proteins during aging.

Using proteomic techniques, we investigated peroxynitrite (ONOO-) and 4-hydroxy-2-nonenal (HNE) modified serum proteins from young and old Fischer 344 rats. Two-dimensional gel electrophoresis/western blot analysis of nitrotyrosine and HNE-histidine revealed that serum proteins were differentially modified by ONOO- and HNE. Among them, 16 of the modified proteins, identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), are involved in blood coagulation, lipid transport, blood pressure regulation, and protease inhibition. Furthermore, nitration and HNE adduction were found to increase with age, lending support to the oxidative stress hypothesis of aging. Our data showed that proteomic techniques can be valuable tools in the study of protein profiling modifications during aging.