A rapid LC-FTMS method for analysis of cysteine, cystine and cysteine/cystine steady-stateredox potential in human plasma

• Type of Material: Article
• Authors: Jennifer M. Johnson, Emory University; Fred Strobel, Emory University; Matthew Reed, Emory University; Jan Pohl, Emory University; Dean P Jones, Emory University
• Language: English
• Date: 2008-10
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2008 Elsevier B.V. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.cca.2008.06.020
• Title of Journal or Parent Work: Clinica Chimica Acta
• ISSN: 0009-8981
• Volume: 396
• Issue: 1-2
• Start Page: 43
• End Page: 48
• Grant/Funding Information: This research was supported by NIH Grant ES009047 and the Emory – Georgia Tech Predictive Health Institute.
• Keywords: oxidative stress; cysteine; cystine; human plasma; FTMS; redox
• Research Categories: Biology, Genetics; Chemistry, Biochemistry

Abstract

Background The steady-state redox potential of the cysteine/cystine couple in human plasma provides a measure of oxidative stress, yet available assays are limited by either specificity or speed of assay. Method The present study evaluated the use of LC-FTMS for identification based on accurate mass combined with quantification by stable isotopic dilution to rapidly determine cysteine and cystine concentration and cysteine/cystine steady-state redox potential in human plasma. Results A simple extraction procedure followed by a rapid LC separation eluted cysteine in 4 min and cystine in 1.5 min with simultaneous measurement of glutathione (GSH) and glutathione disulfide (GSSG). A study of five young (mean age = 25.7) subjects and 5 older (mean age = 67.8 y) subjects showed an increased oxidation with age. Conclusions Analysis by LC-FTMS is suitable for high-throughput analysis of plasma cysteine, cystine and cysteine/cystine steady-state redox potential as clinical measures of oxidative stress.