title: 1-p-chlorophenyl-4,4-dimethyl-5-diethylamino-1-penten-3-one hydrobromide, a sulfhydryl-specific compound which reacts irreversibly with protein thiols but reversibly with small molecular weight thiols.
abstract: 1-p-Chlorophenyl-4,4-dimethyl-5-diethylamino-1-penten-3-one hydrobromide (CDDP) has been shown to react selectively with small molecular weight and protein thiols. The reaction of this compound with thiols can be monitored directly owing to the large decrease (approximately 21,000 M-1 cm-1 at 310 nm) in extinction coefficient subsequent to thiol addition. CDDP reacted stoichiometrically with large molecular weight (greater than 11,000) protein thiols. However, with small molecular weight thiols (less than 500) the reaction was less than stoichiometric, indicating a significant degree of back-reaction. The forward and reverse rate constants have been estimated. The fact that the reaction is reversible enables CDDP to be used for the direct monitoring of the oxidation of small molecular weight thiols.
authors.affiliation: Department of Chemistry and Biochemistry, University of Windsor, Ontario, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Mutus
authors.forename: J D
authors.initials: JD
authors.lastname: Wagner
authors.forename: C J
authors.initials: CJ
authors.lastname: Talpas
authors.forename: J R
authors.initials: JR
authors.lastname: Dimmock
authors.forename: O A
authors.initials: OA
authors.lastname: Phillips
authors.forename: R S
authors.initials: RS
authors.lastname: Reid
mesh_terms: D002722:Chlorobenzenes; D007659:Ketones; D007700:Kinetics; D011485:Protein Binding; D011506:Proteins; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013438:Sulfhydryl Compounds; D013439:Sulfhydryl Reagents
chemical_list: D002722:Chlorobenzenes; D007659:Ketones; D011506:Proteins; D013438:Sulfhydryl Compounds; D013439:Sulfhydryl Reagents; C059871:1-(4-chlorophenyl)-4,4-dimethyl-5-diethylamino-1-penten-3-one