Spectroscopic determination of cytochrome c oxidase content in tissues containing myoglobin or hemoglobin.

National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Analytical Biochemistry (Impact Factor: 2.31). 07/1996; 237(2):274-8. DOI: 10.1006/abio.1996.0239
Source: PubMed

ABSTRACT A simple spectroscopic method for determining the cytochrome c oxidase, cytochrome a, a3, content in tissue and mitochondria samples independent of myoglobin or blood contamination is described. Using tissue homogenates solubilized in Triton X-100, this assay relies on the selective reduction of mitochondrial cytochromes by the action of potassium cyanide. Monitoring the optical absorbance of these samples at 605 nm provided a quantitative determination of cytochrome c oxidase content in the presence of myoglobin or blood. The cytochrome c oxidase content of porcine heart mitochondria and whole tissue was determined to be 0.85 nmol/mg protein and 30.5 nmol/g wet wt, respectively.

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