Apolipoprotein B is a major protein constituent of chylomicrons (apo B-48), LDL (apo B-100) and VLDL (apo B-100). Apo B-100 functions as a recognition signal for the cellular binding and internalization of LDL particles by the apoB/E receptor.
Involvement in disease: Defects in APOB are a cause of hypobetalipoproteinemia familial type 1 (FHBL1) . A disorder characterized by highly reduced plasma concentrations of low density lipoproteins, and dietary fat malabsorption. Clinical presentation