Apolipoprotein B is the dominant protein constituent of LDL. The concentration of Apo B in normal plasma is 90 mg per 100 ml. Apo B is thought to stabilize lipid emulsions, serve as a cofactor and modulator of enzymatic reactions, manage export of lipids out of cells and direct lipids to target organs. Apo B levels are positively correlated with the risk of coronary disease. Apo B levels may be a more sensitive predictor of cardiovascular risk than LDL levels and do not involve fasting for accurate measurement. Two forms of Apo B exist: Apo B-100 and Apo B-48. The first is found in VLDL and LDL and is produced by the liver. The second is found in chylomicrons and originates in the intestine. . Description: Human plasma. Alternative Names: Apolipoprotein B protein, Apo-B protein, Apo B protein, Low Density lipoprotein protein, LDL protein