Apolipoprotein(a)

Apolipoprotein(a) is a specific type of apolipoprotein that is most commonly associated with lipoprotein(a), a type of lipoprotein found in the blood. It is encoded by the LPA gene in humans.

Structure

Apolipoprotein(a) is a large glycoprotein with a molecular weight of approximately 500,000 daltons. It is composed of a single polypeptide chain that is highly homologous to plasminogen, a key enzyme in the fibrinolysis system. The protein contains multiple repeating kringle domains, which are thought to play a role in its binding to lipoprotein(a).

Function

The primary function of apolipoprotein(a) is to bind to low-density lipoprotein (LDL) particles in the blood, forming lipoprotein(a). This complex is thought to play a role in atherogenesis, the process of forming atheromatous plaques in the blood vessels. Elevated levels of lipoprotein(a) in the blood have been associated with an increased risk of cardiovascular disease.

Clinical significance

Apolipoprotein(a) is a major component of lipoprotein(a), and elevated levels of this lipoprotein have been associated with an increased risk of cardiovascular disease. This is thought to be due to the pro-atherogenic and pro-thrombotic properties of lipoprotein(a). Genetic variations in the LPA gene, which encodes apolipoprotein(a), have also been associated with variations in the levels of lipoprotein(a) in the blood.

See also

• Apolipoprotein
• Lipoprotein(a)
• Cardiovascular disease
• Atherogenesis