Yeast mitochondrial inner membrane 30 kd hydrophobic protein: properties and interaction with phospholipids.

A 30 kd hydrophobic protein is extracted from yeast mitochondrial inner membrane. It is present in wild yeast strains but absent in mitochondrial DNA lacking mutants. The isoelectric point of the protein and its solubility in various organic solvents are determined. The fluorescence of a tryptophan residue near the surface of the 30 kd protein dissolved in butanol-1, can be quenched by phospholipids containing unsaturated fatty acids. Results are in accordance with the 30 kd protein being an integral protein of the yeast mitochondrial inner membrane.