Phosphatidylethanolamine activation of the purified and delipidated cytochrome-c4:o oxidase from Azotobacter vinelandii

Abstract

The effects of exogenous phosphatidylethanolamine (PE) on the activity of a purified and a delipidated cytochrome oxidase from Azotobacter vinelandii were studied. The Vmax values of N,N,N′,N′-tetramethyl-p-phenylenediamine oxidation by the cytochrome oxidase increased linearly as a direct function of the amount of exogenously added PE. Some PE remained bound to the oxidase, even after extensive delipidation. Results indicated PE might serve a vital function in maintaining the enzymic activity of this oxidase in A. vinelandii.