Heme-associated subunit complex of cytochrome c oxidase identified by a new two-dimensional gel electrophoresis.

A Novel two-dimensional system (isoelectric focusing in the first dimension and sodium dodecyl sulfate-urea electrophoresis in the second) was used to determine the pI values of beef heart subunits of cytochrome c oxidase. The results identified a heme-associated complex of Subunits I, II, and IV. Conditions mitigate against migration of free heme.