Evidence for an Oxygenated Intermediate in the Tryptophan Pyrrolase Reaction

During the steady state of tryptophan pyrrolase (a hemecontaining dioxygenase) reaction, a new spectral species was observed having absorption maxima at 415, 545, and 580 mµ. This spectrum was due neither to a ferric nor a ferrous state of the heme nor a mixture of both. Since it was observed only in the presence of both tryptophan and oxygen and resembled the spectra of known oxygenated heme protiens, it was interpreted to be due to an oxygenated intermediate, presumably a ternary complex of oxygen, tryptophan, and the enzyme.