Analysis of native human plasma proteins and haemoglobin for the presence of bityrosine by high-performance liquid chromatography.
Generation of reactive oxygen species in vivo results in oxidative-damage to cellular components, including proteins. Due to the relatively long half-lives of several blood proteins the cumulative formation of oxidatively damaged proteins might serve as a biomarker for reactive oxygen species formation. The most prominent sources of reactive oxygen species in vivo are site-specific metal ion-catalyzed reactions of the Fenton and Haber-Weiss types and the H2O2/peroxidase system. In vitro oxidation of L-tyrosine using a peroxidase or Cu++/H2O2 system gives rise to the formation of a highly fluorescent substance, bityrosine. High-performance liquid chromatography (HPLC) analysis of acid hydrolyzed serum albumin after oxidation with peroxidase/H2O2 or with Cu++/H2O2 showed that bityrosine had been formed whereas oxidation of this protein with Fe(III)/ascorbate did not result in the formation of bityrosine. Bityrosine could not be detected in human plasma proteins or haemoglobin with the detection limit of one pmol per mg protein.
Daneshvar
B
B
Institute of Toxicology, National Food Agency of Denmark, Søborg, Denmark.
Frandsen
H
H
Dragsted
L O
LO
Knudsen
L E
LE
Autrup
H
H
D000328:Adult; D000397:Air Pollution / Q000032:analysis; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
D001798:Blood Proteins; D006454:Hemoglobins; D014443:Tyrosine; C007543:dityrosine