Copper is not essential for the catalytic activity of L-tryptophan 2,3-dioxygenase.

Purified from the bacteria grown in Japan according to the method described by Ishimura and his co-workers and carried to the U. S. in " Different fractions of eluates from Sephadex G-200 column chromatography.These preparations were obtained from the same batch of e Purified according to the method described by Makino and Ishimura (19).'Purified and analyzed in Keio University, Japan.the enzyme.a frozen state (19).bacteria as in Table I but purified by a modified Method 11 in the presence of 2 mM ethylenediaminetetraacetate.