In situ circular dichroic electrochemical study of bilirubin and bovine serum albumin complex.
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.
Bai
Hanying
H
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
Liu
Xiaoqiang
X
Zhang
Zheling
Z
Dong
Shaojun
S
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
D012709:Serum Albumin; D001663:Bilirubin