An on-column derivatization method for the determination of homocysteine-thiolactone and protein N-linked homocysteine.
Homocysteine (Hcy) is incorporated into protein via a reaction of the thioester Hcy-thiolactone with ε-amino group of a protein lysine residue generating N-Hcy-protein. This reaction impairs and alters protein's function and has been implicated in atherothrombotic disease. Here, we describe new high-performance liquid chromatography assays for the determination of Hcy-thiolactone, protein N-linked Hcy, and Hcy based on an on-column derivatization with o-phthaldialdehyde and fluorescence detection. The on-column derivatization generates narrow peaks, which allows fast run times (3-5 min) and facilitates determination of N-linked Hcy directly from acid hydrolysates of plasma protein. Utility of these assays was demonstrated with human urine and plasma samples.
Głowacki
Rafał
R
Department of Environmental Chemistry, University of Łódź, Poland.
Bald
Edward
E
Jakubowski
Hieronim
H
D001798:Blood Proteins / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation; D006710:Homocysteine / Q000031:analogs & derivatives / Q000032:analysis*; D006801:Humans; D012016:Reference Values
D001798:Blood Proteins; D006710:Homocysteine