A Novel Terminal Oxidase, Cytochromebaa3Purified from Aerobically GrownPseudomonas aeruginosa: It Shows a Clear Difference between Resting State and Pulsed State

摘要

A novel type of cytochromecoxidase was purified to homogeneity fromPseudomonas aeruginosawhich was grown aerobically. The purified oxidase contained two molecules of hemea, two atoms of copper, and one molecule of protoheme per molecule. One of the two hemeamolecules in the oxidase reacted with carbon monoxide, so that the enzyme was ofbaa3-type. The oxidase molecule was compoeed of three subunits with molecular weights of 38,000, 57,000, and 82,000. Although the oxidase oxidized ferrocytochromec-550 obtained from the bacterial cells grown aerobically, the oxidizing activity was not high. The“resting form”and the“pulsed form”of the oxidase were observed clearly with this enzyme, and the transition from the resting form to the pulsed form was accompanied by a distinct change of the enzymatic activity. The difference in the kinetics of the catalytic reactions between the two forms is di