title: In situ circular dichroic electrochemical study of bilirubin and bovine serum albumin complex.
abstract: The electrooxidation of bilirubin (BR) and bovine serum albumin (BSA) complexes was studied by in situ circular dichroism (CD) spectroelectrochemistry. The result showed that the mechanism of the whole electrooxidation process of this complex corresponded to electrochemical processes (EE mechanism) in aqueous solution. Some parameters of the process were obtained by double logarithm method, differential method and nonlinear regression method. In visible region, CD spectra of the two enantiomeric components of the complex and their fraction distribution against applied potentials were obtained by singular value decomposition least-square (SVDLS) method. Meanwhile, the distribution of the five components of secondary structure was also obtained by the same method in far-UV region. The peak potential gotten from EE mechanism corresponds to a turning point for the component transition, beyond which the whole reaction reaches a new equilibrium. Under applied positive potentials, the enantiomeric equilibrium between M and P form is broken and M form transfers to its enantiomer of P, while the fraction of alpha-helix increases and that improves the transition to P form.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Hanying
authors.initials: H
authors.lastname: Bai
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Liu
authors.forename: Zheling
authors.initials: Z
authors.lastname: Zhang
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
mesh_terms: D000818:Animals; D001663:Bilirubin / Q000737:chemistry*; D002417:Cattle; D002942:Circular Dichroism / Q000379:methods*; D004563:Electrochemistry; D006860:Hydrogen Bonding; D007700:Kinetics; D008962:Models, Theoretical; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012709:Serum Albumin / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D013223:Statistics as Topic; D014466:Ultraviolet Rays
chemical_list: D012709:Serum Albumin; D001663:Bilirubin