The uptake of cholesterol at the small-intestinal brush border membrane is inhibited by apolipoproteins.

The uptake of free and esterified cholesterol at the brush border membrane is protein-mediated. Here we show that this sterol uptake is effectively inhibited by exchangeable serum apolipoproteins. Binding of the apolipoprotein to the brush border membrane mediates the inhibitory effect. Evidence is presented to show that the structural motif responsible for the inhibition is the amphipathic alpha-helix.