Which Oxidant Is Really Responsible for Sulfur Oxidation by Cytochrome P450?

Clarifying a conundrum: The question of whether Compound I or Compound 0 (Cpd I or Cpd 0) is the reactive oxidant in the sulfoxidation of thiafatty acids by P450 is addressed by theory, which demonstrates that Cpd I leads to an extremely fast process, while Cpd 0 is at least six orders of magnitude slower. Most likely, thiafatty acids promote Cpd I formation even in the T→A mutant of P450BM3.