Lipoprotein

A lipoprotein is a biochemical assembly that contains both proteins and lipids and may be structural or catalytic in function. Lipoproteins may be enzymes, proton pumps, ion pumps, or some combination of these functions. Examples include the high density and low density lipoproteins of the blood and the transmembrane proteins of the mitochondrion and the chloroplast.

The lipids are often an essential part of the complex, even if they seem to have no catalytic activity themselves. To isolate transmembrane lipoproteins from their associated membranes, detergents are often needed.