Premium
Enhanced Photoinduced Electron Transfer Through a Tyrosine Relay in a De Novo Designed Protein Scaffold Bearing a Photoredox Unit and a Fe II S 4 Site
Author(s) -
Tebo Alison,
Quaranta Annamaria,
Pecoraro Vincent L.,
Aukauloo Ally
Publication year - 2021
Publication title -
chemphotochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.13
H-Index - 18
ISSN - 2367-0932
DOI - 10.1002/cptc.202100014
Subject(s) - electron transfer , tyrosine , chemistry , intramolecular force , photodissociation , photochemistry , photoinduced electron transfer , reaction rate constant , amino acid , kinetics , redox , proton coupled electron transfer , electron transport chain , stereochemistry , biochemistry , physics , organic chemistry , quantum mechanics
Electron transfer (ET) processes in biology over long distances often proceed via a series of hops, which reduces the distance dependence of the rate of ET. The protein matrix itself can be involved in mediating ET directly through the participation of redox‐active amino acids. We have designed an electron transfer chain incorporated into a de novo protein scaffold, which is capable of photoinduced intramolecular electron transfer between a photoredox unit and a Fe II S 4 site through a tyrosine amino acid relay. The kinetics were characterized by nanosecond laser pulse photolysis and revealed that electron transfer from [Ru III bpymal] 3+ proceeds most efficiently via a tyrosine located ∼16 Å from Rubpymal (bpymal=1‐((1‐([2,2′‐bipyridin]‐4‐yl)‐1H‐1,2,3‐triazol‐4‐yl)methyl)‐1H‐pyrrole‐2,5‐dione). Removal of the tyrosine as the electron relay station results in a 20‐fold decrease in the apparent rate constant for the electron transfer.