High density lipoproteins (HDL) are isolated from fresh, pooled human plasma by ultracentrifugation. The HDL are delipidated and the APOA1 is purified by chromatography in 6M urea.
Ultracentrifugation and chromatography
>= 98% by SDS-PAGE
Lyophilized from 0.01 M ammonium bicarbonate
Store at -20°C or lower on dry atmosphere. After reconstitution with 1 mL of 5 M guanidine-HCl, store at 2-8°C no longer than 4 weeks.
Universal Precautions. Safe laboratory practices should be used when handling this material.
Apolipoprotein A1, which has a molecular weight of 28 kDa and a pI of 5.6, activates LCAT by catalyzing the esterification of cholesterol. Apolipoproteins are soluble in aqueous solutions. However, due to their amphipathic structure, apolipoproteins self-associate into oligomers at high protein concentrations. At concentrations above 1 mg/mL, there may be little or no free monomer in the solution. Apolipoproteins exist as monomers in buffers containing 5 M guanidine-HCl or 6M urea.
This gene encodes apolipoprotein A-I, which is the major protein component of high density lipoprotein (HDL) in plasma. The protein promotes cholesterol efflux from tissues to the liver for excretion, and it is a cofactor for lecithin cholesterolacyltransferase (LCAT) which is responsible for the formation of most plasma cholesteryl esters. This gene is closely linked with two other apolipoprotein genes on chromosome 11. Defects in this gene are associated with HDL deficiencies, including Tangier disease, and with systemic non-neuropathic amyloidosis. [provided by RefSeq