Concentration: | 1 mg / ml, determined by the Lowry method |
Source: | From fresh human plasma that has tested negative for Hepatitis C, HIV-I and HIV-II antibodies as well as Hepatitis surface antigens. |
Purification: | After series ultracentrifugations, High Density Lipoprotein (HDL) is isolated from human plasma. Apo AII is purified from delipidated HDL, followed by gel-filtration and DEAE-Sepharcyl chromatography. |
Purity: | ≥ 98% by SDS-PAGE |
Buffer: | 20 mM Tris-HCl, 140 mM NaCl, 0.02% NaN3, 0.5 mM EDTA, pH 7.4. |
Storage: | -20°C for long-term storage, 4°C for short- term storage. Aliquot to avoid repeated freezing and thawing. |
Importance
Apo AII comprises 25% of HDL. It exists in human plasma as a dimer of 2 identical chains of 77 amino acid residues, joined by disulfide. The molecular weight is reported to be 8.7 kDa for a single chain (Brewer et al., 1972).
Studies on mouse reported that apo AII may be proatherogenic (Warden et al., 1993); however, case-control study in the large European Prospective Investigation demonstrated that plasma Apo AII concentrations were strongly inversely correlated with CHD events (Birjmohun et al., 2007).
Birjmohun, R. S., G. M. Dallinga-Thie, J. A. Kuivenhoven, E. S.g. Stroes, J. D. Otvos, N. J. Wareham, R. Luben, J. J.p. Kastelein, K.-T. Khaw, and S. M. Boekholdt. "Apolipoprotein A-II Is Inversely Associated With Risk of Future Coronary Artery Disease." Circulation 116 (2007): 2029-035.
Brewer, H. B., S. E. Lux, R. Ronan, and K. M. John. "Amino Acid Sequence of Human ApoLp-Gln-II (apoA-II), an Apolipoprotein Isolated from the High-Density Lipoprotein Complex." Proceedings of the National Academy of Sciences 69.5 (1972): 1304-308.
Warden, C., C. Hedrick, J. Qiao, L. Castellani, and A. Lusis. "Atherosclerosis in Transgenic Mice Overexpressing Apolipoprotein A-II." Science 261 (1993): 469-72.