Electronic Structure of the Neutral Tyrosine Radical in Frozen Solution. Selective ~2H-, ~13C-, and ~17O-Isotope Labeling and EPR Spectroscopy at 9 and 35 GHz

摘要

Selective ~2H-, ~13C-, and ~17O-isotope labeling of the tyrosine amino acid has been used to map the unpaired π-electron spin-density distribution of the UV_generated neutral L-tyrosine phenoxy radical in alkaline frozen solution. The use of ~13C and ~17O labels allowed accurate determination of the full spin-density distribution and provided more insight in the geometrical structure of the neutral tyrosine radical in vitro.