Membrane-Bound Respiratory Chain of Pseudomonas aeruginosa Grown Aerobically. A KCN-Insensitive Alternate Oxidase Chain and Its Energetics

Publisher Website
Google Scholar
Abstract
There was found to be a KCN-insensitive, alternate oxidase chain branching from the ordinary oxidase chain in the respiratory chain of Pseudomonas aeruginosa grown aerobically. The alternate oxidase activity was highly resistant to KCN, and had a lower affinity for oxygen than ordinary cytochrome oxidase did. The branching point of the alternate oxidase chain from the ordinary oxidase chain was shown to be localized behind cytochrome b . The KCN-inserisitive alternate oxidase chain was inhibited slightly with antimycin A and intensively with 2-thenoyl-trifluoroacetone. The former inhibited the respiration behind cytochrome b and the latter before cytochrome b . N,N,N′,N′ -Tetramethyl- p -phenylenediamine oxidase-negative mutant (T105) was prepared from P. aeruginosa . The mutant clearly lacked a functional ordinary cytochrome oxidase, but had the KCN-insensitive alternate oxidase chain and could grow aerobically. The KCN-insensitive alternate oxidase chain had a H + /O ratio of 4, suggesting the existence of two energy-coupling sites in the chain. Under the conditions where both ordinary oxidase and alternate oxidase chains were functioning, the H + /O ratio of the parent strain was 5.6. From these data, we also discuss the energetics of the ordinary oxidase chain in the respiratory chain of aerobic P. aeruginosa .

This publication has 1 reference indexed in Scilit: