Electrochemical Monitoring of Reduction and Binding of Iron Amyloid-B Complexes at Boron-Doped Diamond Electrode

摘要

The amino acid residues for reduction and binding of amyloidpeptide (A)e(III) complexes wereinvestigated mainly by voltammetry at boron-doped diamond electrodes. Distinguished from naturalFe(III)(16) complex, the recovering redox behavior of Fe(III)(Y) complex showed higherfree-ion concentration and weaker bonding ability, evidencing that Fe(III) primarily binded to A viaTyr10. Whereas, there were no detectable distinctions in electroactivity along with UV/vis absorptivityand fluorescence quenching between Fe(III)(16) and Fe(III)(H), which indicates thatthree His were eliminated in direct bonding to Fe(III). Compared with Fe(16), the significantenhancement of Ip(Fe(II)-Fe(0)) in Fe(12), Fe(255), and even the exogenous Met to Fe(III)provided electrochemical evidences that the reduction of Fe(III) to Fe(II) was aroused by Met directly.Zn(II) which was redox-silent, also contributed the pathogenesis but can not affect the redox signal ofFe(III).