Stoffel W, Därr W
Hoppe Seylers Z Physiol Chem. 1976 Feb;357(2):127-37. doi: 10.1515/bchm2.1976.357.1.127.
High denisty apolipoprotein A-1 (apoLp A-I) has been prepared in a chromatographically and immunochemically homogeneous form. This apoprotein forms trimeric and tetrameric aggregates in aqueous solutions at higher concentrations. ApoLp A-I has been recombined in almost quantitative yield in the presence of lysolecithin with phosphatidylcholine and sphingomyelin to particles of reproducible stoichiometry. Lysolecithin is not required for the interactions of lecithin and sphingomyelin with the apoprotein A-I or for the stability of these complexes. Dialysis removes most of the lysolecithin without the loss of lecithin and sphingomyelin. ApoLp A-I-lecithin particles have a molecular weight of 200 000 and contain 50 molecules lecithin and 25 of lysolecithin. ApoLp A-I-sphingomyelin complexes contain 50 sphingomyelin and 13 lysolecithin molecules. The former particles show up as discs of 100 A diameter, and the latter particles are 250 A in diameter. Their thickness was estimated as 25 A in the apoLp A-I lecithin and 60 A in the apoLp A-I-sphingomyelin particles. ApoLp A-I and lysolecithin form complexes whose densities depend on the lysolecithin concentration. Lysolecithin enhances the binding of phosphatidylcholine to apoLP A-I, yielding lipoprotein complexes with decreasing density. The yield of apoLp A-I-sphingomyelin-lysolecithin complexes is proportional to the lysolecithin concentration. The ratio of apoLp A-I to sphingomyelin in all these complexes remains constant.
高密度载脂蛋白A-1（apoLp A-I）已通过色谱法和免疫化学方法制备成均一形式。这种载脂蛋白在较高浓度的水溶液中形成三聚体和四聚体聚集体。在溶血卵磷脂存在的情况下，apoLp A-I与磷脂酰胆碱和鞘磷脂以可重复的化学计量比重组为颗粒，产率几乎达到定量。溶血卵磷脂对于卵磷脂和鞘磷脂与载脂蛋白A-I的相互作用或这些复合物的稳定性并非必需。透析可去除大部分溶血卵磷脂，而不会损失卵磷脂和鞘磷脂。ApoLp A-I-卵磷脂颗粒的分子量为200000，含有50个卵磷脂分子和25个溶血卵磷脂分子。ApoLp A-I-鞘磷脂复合物含有50个鞘磷脂分子和13个溶血卵磷脂分子。前者颗粒呈现为直径100埃的圆盘状，后者颗粒直径为250埃。据估计，它们在ApoLp A-I-卵磷脂颗粒中的厚度为25埃，在ApoLp A-I-鞘磷脂颗粒中的厚度为60埃。ApoLp A-I与溶血卵磷脂形成密度取决于溶血卵磷脂浓度的复合物。溶血卵磷脂增强了磷脂酰胆碱与apoLP A-I的结合，产生密度降低的脂蛋白复合物。ApoLp A-I-鞘磷脂-溶血卵磷脂复合物的产率与溶血卵磷脂浓度成正比。所有这些复合物中ApoLp A-I与鞘磷脂的比例保持恒定。
