title: The electrochemically induced conformational transition of disulfides in bovine serum albumin studied by thin layer circular dichroism spectroelectrochemistry.
abstract: The conformational transition of disulfides in bovine serum albumin (BSA) induced by electrochemical redox reaction of disulfides were monitored by in-situ circular dichroism (CD) spectroelectrochemistry, with a long optical path thin layer cell and analyzed by a singular value decomposition least square (SVDLS) method. Electrochemical reduction of disulfides drives the left-handed conformation of disulfides changed into the right-handed. At open circuit, eight of the 17 disulfides were of left-handed conformation. Four of the 17 disulfides took part in the electrochemical reduction with an EC mechanism. Only one-fourth of the reduced disulfides returned to left-handed conformation in the re-oxidation process. Some parameters of the electrochemical reduction process, i.e. the number of electrons transferred and electron transfer coefficient, n = 8, alpha n = 0.15, apparent formal potential, E1(0') = -0.65(+/-0.01) V, standard heterogeneous electron transfer rate constant, k1(0) = (2.84 +/- 0.14) x 10(-5) cm s(-1) and chemical reaction equilibrium constant, Kc = (5.13 +/- 0.12) x 10(-2), were also obtained by double logarithmic analysis based on the near-UV absorption spectra with applied potentials.
authors.affiliation: Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhu
authors.forename: G
authors.initials: G
authors.lastname: Cheng
authors.forename: S
authors.initials: S
authors.lastname: Dong
mesh_terms: D000465:Algorithms; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004220:Disulfides / Q000737:chemistry*; D004563:Electrochemistry; D007202:Indicators and Reagents; D011487:Protein Conformation; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004220:Disulfides; D007202:Indicators and Reagents; D012710:Serum Albumin, Bovine