Campbell AM, Capuano A, Chan SHP. A cholesterol-binding and transporting protein from rat liver mitochondria.
BIOCHIMICA ET BIOPHYSICA ACTA 2002;
1567:123-32. [PMID:
12488045 DOI:
10.1016/s0005-2736(02)00607-7]
[Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
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.
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