Identification of the Protonated Oxygenic Ligands of Ribonucleotide Reductase Intermediate X by Q-Band ~1,2H CW and Pulsed ENDOR

摘要

We report CW and pulsed Q-band ~1,2H ENDOR measurements of intermediate X formed during the assembly of the diferric tyrosyl radical cofactor of the R2 subunit in ribonucleotide reductase. These studies, performed with H_2O and D_2O buffers, were designed to determine whether the exchangeable proton signals are associated with an Hydroxox bridge, a terminal water, or both.