Divergence in nonspecific hydrophobic packing interactions in the apo state, and its possible role in functional specialization of mitochondrial and microsomal cytochrome b5.

The outer mitochondrial membrane isoform of mammalian cytochrome b(5) (OM b(5)) is distinguished from the microsomal isoform (Mc b(5)) by its considerably greater stability. In contrast, OM and Mc apocytochrome b(5) (apo-b(5)) exhibit similar thermodynamic stability. Contributing substantially to the greater stability of OM b(5) relative to that of Mc b(5… CONTINUE READING