Studying Hopping in Another Pathway of Azurin

Hopping was investigated through an established electron transfer pathway that traverses the interior of azurin. Tyrosine was installed in the 48 site of azurin with the hope that the sequestration would circumvent deprotonation of the radical cation form, thereby allowing for hopping to occur through tyrosine. Two metal-modified proteins were made for the study. Time-resolved UV-VIS spectroscopy measurements indicate that, while the substitution of tyrosine can encourage fast electron transfer between the ruthenium and the copper center, it does not actually participate in hopping. In the hope of generating more experimental demonstrations of multistep tunneling at different distances, a hopping system is installed along another known electron transfer pathway in azurin. The system discussed in this chapter is through a network of hydrogen and covalent bonds traversing the protein's interior, ending at th