title: Kinetic studies of the oxidation of glutathione in protein refolding buffer.
abstract: Here, we examined the change of glutathione (GSH) under different conditions and determined the appropriate kinetic schemes to describe its change of concentration. GSH was continuously oxidized into glutathione disulfide (GSSG) as incubation period increased at the temperatures ranging from 10 to 50 degrees Celsius while certain oxidation by-products were also observed at the later stage of reaction at higher temperatures (70-90 degrees Celsius). The addition of 0.3 mM GSSG in 3 mM GSH solution delayed the onset of GSH oxidation without significantly changing the rate of GSH oxidation. Our results also revealed that GSH oxidation could be facilitated upon the addition of copper (II) ion whereas GSH oxidation was found to be decelerated when EDTA was present. In kinetic analysis, the reaction orders of GSH oxidation under various conditions were determined. Moreover, the temperature dependence of the rate of GSH oxidation was modeled by Arrhenius and Eyring equations and resultant activation parameters were also presented.
authors.affiliation: Department of Chemical Engineering, National Taiwan University, No.1, Sec.4, Roosevelt Rd, Taipei 10617, Taiwan. sswang@ntu.edu.tw
authors.forename: Steven S-S
authors.initials: SS
authors.lastname: Wang
authors.forename: Ying-Tz
authors.initials: YT
authors.lastname: Hung
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Lin
mesh_terms: D002021:Buffers; D002244:Carbon / Q000737:chemistry; D002845:Chromatography / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D004492:Edetic Acid / Q000737:chemistry; D019277:Entropy; D005978:Glutathione / Q000737:chemistry*; D019803:Glutathione Disulfide / Q000737:chemistry*; D006851:Hydrochloric Acid / Q000737:chemistry; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry*; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D002021:Buffers; D011506:Proteins; D002244:Carbon; D004492:Edetic Acid; D005978:Glutathione; D006851:Hydrochloric Acid; D010100:Oxygen; D019803:Glutathione Disulfide