Apolipoprotein A-I from human plasma 

Major protein components in high density lipoprotein (HDL)

Solution in 10 mM ammonium bicarbonate

Apo-AI comprises ~70% of the protein moiety in HDL. It is a single polypeptide chain consisting of 245 amino acids with glutamic acid as the C-terminal residue and aspartic acid as the N-terminal residue. The molecular mass is reported to be 28.3 kDa. The protein is made up of one major isoform (pI 5.6) and two minor isoforms (pI 5.53 and 5.46). Apo-AI shows a high content of α-helix structure. The amphipathic regions in the α-helix structure seem to be responsible for lipid binding capacity. In aqueous solution, Apo-AI shows self-association with minor conformation change. Apo-AI activates lecithin-cholesterol (LCAT) acyltransferase, which is responsible for cholesterol esterification in plasma.

Apo-AI levels in normal plasma are 90-130 mg/dl. Apo-AI levels may be inversely related to the risk of coronary disease.

≥85% (SDS-PAGE)

buffered aqueous solution

mol wt 28.3 kDa

human ... APOA1(335)

dry ice

−20°C

Menzel, H.J. J. Biol. Chem. 259, 3070, (1984) abstract

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