====== Apolipoprotein ====== Apolipoproteins are [[protein]]s that bind [[lipid]]s (oil-soluble substances such as fat and cholesterol) to form [[lipoprotein]]s. They transport the lipids through the lymphatic and circulatory systems. The lipid components of lipoproteins are insoluble in water. However, because of their detergent-like (amphipathic) properties, apolipoproteins and other amphipathic molecules (such as phospholipids) can surround the lipids, creating the lipoprotein particle that is itself water-soluble, and can thus be carried through water-based circulation (i.e., blood, lymph). Apolipoproteins also serve as enzyme cofactors, receptor ligands, and lipid transfer carriers that regulate the metabolism of lipoproteins and their uptake in tissues. see [[Apolipoprotein C1]]. see [[Apolipoprotein E]]. see [[APOBEC]].