| Autor: |
Minghetti KC; Department of Biochemistry, University of Illinois, Urbana 61801., Gennis RB |
| Jazyk: |
angličtina |
| Zdroj: |
Biochemical and biophysical research communications [Biochem Biophys Res Commun] 1988 Aug 30; Vol. 155 (1), pp. 243-8. |
| DOI: |
10.1016/s0006-291x(88)81075-1 |
| Abstrakt: |
The aerobic respiratory chain of Escherichia coli contains two terminal oxidases, the cytochrome d complex and the cytochrome o complex. Each of these enzymes catalyzes the oxidation of ubiquinol-8 within the cytoplasmic membrane and reduces molecular oxygen. The purpose of this work is to experimentally verify that each of the terminal oxidases yields water as a product with no significant amount of hydrogen peroxide. This was accomplished by preparing membranes which were washed so as to eliminate membrane-associated catalase and peroxidase activities. The NADH oxidase activity of the membrane-bound respiratory chain was measured by monitoring the rates of both NADH and oxygen utilization. This was performed using membranes from strains in which either cytochrome o or cytochrome d were absent. Results using each strain showed two NADH utilized per oxygen, indicating a four-electron reduction of oxygen to water. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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