Use of mutant 125I-perfringolysin O to probe transport and organization of cholesterol in membranes of animal cells.

ABSTRACT: Animal cells strictly control the distribution of cholesterol in their organelle membranes. This regulation requires an efficient machinery to transport insoluble cholesterol between organelles. In the present study, we generate an (125)I-labeled mutant version of Perfringolysin O (PFO), a cholesterol-binding protein, and use it to measure cholesterol in the plasma membrane of intact cells. We also purify plasma membranes from the same cells, which allows us to directly relate cholesterol concentration to (125)I-PFO binding. We show that cholesterol is organized in the plasma membrane in a manner that makes it inaccessible to PFO until its concentration exceeds a threshold of 35 mol% of total lipids. This 35% threshold is in striking contrast to the 5% threshold previously found for PFO bi

SUBMITTER: Das A 

PROVIDER: S-EPMC3696761 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature