title: A highly sensitive single-enzyme homocysteine assay.
abstract: A protocol for measuring the total plasma homocysteine (tHCY) concentration in very small samples using a selective, recombinant homocysteine alpha, gamma-lyase (rHCYase) and a small portable fluorescence reader is described. The rHCYase produces hydrogen sulfide (H(2)S) from tHCY without interference from physiological concentrations of Cys or other plasma components. H(2)S is determined through reactivity with N,N-dibutyl phenylene diamine (DBPDA), which leads to the formation of a fluorescent chromophore. Only 5 microl of plasma/serum sample is required, which can be obtained from a finger prick, suggesting great potential for mass screening. The assay takes approximately 20 min.
authors.affiliation: A/C Diagnostics, LLC and AntiCancer, Inc., 7917 Ostrow Street, San Diego, California 92111, USA.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Tan
authors.forename: Robert M
authors.initials: RM
authors.lastname: Hoffman
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D005453:Fluorescence; D006710:Homocysteine / Q000097:blood*; D006862:Hydrogen Sulfide / Q000378:metabolism; D008190:Lyases / Q000378:metabolism; D015394:Molecular Structure
chemical_list: D006710:Homocysteine; D008190:Lyases; C465024:homocysteine alpha,gamma-lyase; D006862:Hydrogen Sulfide