apoB

Apolipoprotein B (apoB) is the principal structural apolipoprotein of atherogenic lipoproteins, including chylomicrons, very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and lipoprotein(a), and is essential for lipoprotein assembly and lipid transport throughout the circulation^[1][2]. ApoB-containing lipoproteins drive lipid trafficking through pathways that coordinate intestinal dietary fat absorption and hepatic lipoprotein secretion, thereby linking systemic lipid metabolism with cholesterol delivery and clearance mechanisms^[1][3]. Mechanistically, apoB100 functions as the primary ligand for LDL receptor-mediated uptake of LDL particles, enabling receptor-dependent lipoprotein catabolism and regulating the persistence of circulating atherogenic particles^[1][4]. In cardiovascular disease, retention and accumulation of apoB-containing lipoproteins within the arterial wall represent key initiating events in atherosclerotic plaque formation, and elevated apoB particle burden is strongly associated with atherosclerotic cardiovascular risk^[1][2][5]. Compared with related isoforms, apoB100 is synthesized in the liver and is present in VLDL, IDL, LDL, and lipoprotein(a), whereas apoB48 is generated in the intestine through APOB mRNA editing and functions primarily in chylomicron formation and dietary lipid transport^[1][4][6]. Importantly, apoB48 lacks the LDL receptor-binding domain present in apoB100, resulting in distinct roles in lipoprotein metabolism despite their common genetic origin^[3][4]. For experimental applications, apoB and its isoforms are widely used to investigate lipoprotein assembly, remnant metabolism, atherosclerosis mechanisms, and cardiovascular risk assessment in both clinical and preclinical models^[1][2][5].