title: A fluorogenic, mixed-disulfide reagent for thiol assay.
abstract: The design and synthesis of the mixed disulfide (ortho-nitroaniline-N-ethyldithio) 2-[pyridyl-5-thioureido-N'-(5-fluorescein)] are described and the chemical and spectroscopic properties of this thiol-specific fluorogenic reagent are presented. The high reactivity and sensitivity of this reagent in thiol assay are demonstrated with low-molecular-weight thiols and with human carbonmonoxyhemoglobin and its subunits. Comparison with conventional absorption methods shows that at least 100 times less material is needed; moreover, high background absorbance or turbidity do not interfere with the assay.
mesh_terms: D002263:Carboxyhemoglobin / Q000032:analysis; D004735:Energy Transfer; D005452:Fluoresceins / Q000138:chemical synthesis; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D013050:Spectrometry, Fluorescence; D013438:Sulfhydryl Compounds / Q000032:analysis*; D013439:Sulfhydryl Reagents; D013890:Thiourea / Q000031:analogs & derivatives* / Q000138:chemical synthesis
chemical_list: D005452:Fluoresceins; D013438:Sulfhydryl Compounds; D013439:Sulfhydryl Reagents; C048636:(2-nitroaniline-N-ethyldithio)-2-(pyridyl-5-thioureido-N'-(5-fluorescein)); D002263:Carboxyhemoglobin; D013890:Thiourea