A cholesterol-binding and transporting protein from rat liver mitochondria.
In this communication, we present results indicating a protein isolated from rat liver mitochondrial intermembrane space that is capable of binding cholesterol and transporting it between the inner and outer mitochondrial membranes. This protein has a molecular weight of 57.5 kDa by SDS-PAGE; however, under native conditions, there is cholesterol-binding capability only as a 115 kDa dimer. Our data show that this dimeric protein may play a role in the regulation of mitochondrial membrane cholesterol levels, a prerequisite for the optimal activity of inner mitochondrial membrane-associated enzyme complexes. In addition, it appears that this protein is largely responsible for the differences in membrane cholesterol levels observed in normal and hepatoma mitochondria, a discrepancy which may help to explain the lack of energy production via oxidative phosphorylation in malignant tumor mitochondria.
Campbell
Andrew M
AM
Department of Biology, College of Arts and Sciences, Syracuse University, 130 College Place, Syracuse, NY 13244, USA.
Capuano
Aaron
A
Chan
Samuel H P
SH
D000818:Animals; D002784:Cholesterol / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley
D002784:Cholesterol