A 513-kDa protein synthesized in the LIVER. It serves as the major structural protein of low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). It is the ligand for the LDL receptor (RECEPTORS, LDL) that promotes cellular binding and internalization of LDL particles.

Synonyms: 0, Apo B 100, Apo-B-100, ApoB-100, ApoB 100, Apolipoprotein B 100, Apolipoprotein B-100, Apo B-100