Steroidogenic acute regulatory protein (StAR) plays a critical role in steroidogenesis by
enhancing the delivery of substrate cholesterol from the outer mitochondrial membrane to
the cholesterol side chain cleavage enzyme system on the inner membrane. A recombinant
StAR protein lacking the first N-terminal 62 amino acid residues that includes the
mitochondrial targeting sequence was shown to stimulate the transfer of cholesterol and β-
sitosterol from liposomes to heat-treated mitochondria in a dose-, time-, and temperature …