Which apolipoprotein activates capillary lipoprotein lipase?

Apolipoprotein C-II plays a crucial role in lipid metabolism by activating lipoprotein lipase, an essential enzyme found on the endothelium of capillaries. This enzyme is responsible for the hydrolysis of triglycerides within lipoproteins, leading to the release of free fatty acids that can be taken up by tissues, especially muscle and adipose tissue.

The activation of lipoprotein lipase by ApoC-II is critical for the metabolism of chylomicrons and very low-density lipoproteins (VLDL), both of which contain high levels of triglycerides. When ApoC-II is present on these lipoproteins, it promotes their interaction with lipoprotein lipase, thereby facilitating the breakdown of triglycerides into usable fatty acids.

The other apolipoproteins mentioned have different functions in lipid metabolism. ApoA-1 is primarily involved in the formation of high-density lipoproteins (HDL) and the process of reverse cholesterol transport. ApoB-100 is a structural component of low-density lipoproteins (LDL) and serves as a ligand for the LDL receptor, but does not activate lipoprotein lipase. ApoE is involved in the metabolism of lipoproteins as well,