title: Fluorometric assay of tiopronin based on inhibition of multienzyme redox system.
abstract: In this paper, a simple and sensitive fluorimetric method for the determination of tiopronin (N-(2-mercaptopropionyl)-glycine) is proposed. The method is based on the strong inhibitory effect of tiopronin on the multienzyme redox system of hemoglobin, nicotinamide adenine dinucleotide (NADH) and H(2)O(2), in which the intrinsic fluorescence of NADH was employed as the detection signal. The calibration graph is linear in the range 6.13 x 10(-7) to 6.13 x 10(-6) M with a detection limit of 1.65 x 10(-7) M and the relative standard deviation of 2.02%. Kinetics in the pseudo-first-order conditions was investigated by stopped-flow spectrofluorometry and the inhibition mechanism of tiopronin was verified of the competitive type.
authors.affiliation: Department of Chemistry, Wuhan University, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Ruxiu
authors.initials: R
authors.lastname: Cai
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Liu
authors.forename: Xinguo
authors.initials: X
authors.lastname: Wu
mesh_terms: D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors*; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence / Q000379:methods*; D008625:Tiopronin / Q000032:analysis*
chemical_list: D009097:Multienzyme Complexes; D008625:Tiopronin