Reversibility of Electron Transfer in TrpH-TyrOH Peptide

The Electron Transfer （ET） in TrpH-TyrOH was researched in detail. It was found that the rate, even the direction, of the ET in this peptide were significantly dependent on the pH. Also,the ration of concentration of tyrosine residue to that of tryptophan residue is dependent on the pH. In terms or this dependence, the pKa（Trp+） and the pKa（TyrOH） in this peptide was obtained, with the values 6.2 and 11.3 respectively.