3-Nitrotyrosine in the proteins of human plasma determined by an ELISA method.

摘要: The modification of tyrosine residues in proteins to 3-nitrotyrosine by peroxynitrite or other potential nitrating agents has been detected biological systems that are subject oxidative stress. A convenient semi-quantitative method developed assay nitrated fluids and homogenates using a competitive ELISA our laboratory. This selectivity 3-nitro-l-tyrosine variety peroxynitrite-treated (BSA, human serum albumin (HSA), alpha1-antiprotease inhibitor, pepsinogen fibrinogen) also peptide, but had low affinity for free 3-nitro-L-tyrosine 3-chloro-L-tyrosine. IC50 values the inhibition antibody binding different were range 5-100 nM, suggesting discriminated between nitrotyrosine environments. presence plasma was Western blot analysis quantified ELISA. concentration 0. 12+/-0.01 microM nitro-BSA equivalents measured normal which increased elevated inflammatory conditions. HSA low-density lipoprotein (LDL) isolated from contained 0.085+/-0.04 03+/-0.006 nmol equivalents/mg protein, respectively. Comparison level nitration LDL absence indicates presumably oxidation is inhibited antioxidants. consistent with previous reports implicating lipoproteins oxidized blood.