The binding by an NAD-affinity matrix of contaminating dehydrogenases in cytochrome c oxidase preparations.

An NAD-matrix is capable of the separation of three contaminant reductase activities from highly purified beef heart cytochrome c oxidase. Non-specific binding of cytochrome c oxidase occurs as well. When the matrix is saturated with respect to the non-specific binding, continued binding of the reductases can be observed. As a consequence of equilibration with the matrix, the turnover numbers of the unbound cytochrome c oxidase are increased.