MEASUREMENT AND PREDICTION OF THE RATES OF SPONTANEOUS TRANSFER OF PHOSPHOLIPIDS BETWEEN PLASMA-LIPOPROTEINS
MEASUREMENT AND PREDICTION OF THE RATES OF SPONTANEOUS TRANSFER OF PHOSPHOLIPIDS BETWEEN PLASMA-LIPOPROTEINS
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DOI：
10.1016/0005-2760(84)90156-5
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发表时间：
1984-01-01
期刊：
影响因子：
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通讯作者：
POWNALL, HJ
中科院分区：
文献类型：
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作者：
MASSEY, JB;HICKSON, D;POWNALL, HJ
本报告的目的是建立用反相高效液相色谱法测定的磷脂的疏水性与其自发转移率之间的相关性，并利用这种相关性来预测任何脂蛋白中任何同源脂质的转移率。研究了一系列荧光或放射性标记磷脂在天然和重组血清脂蛋白之间的转移机制。荧光磷脂酰胆碱包括sn-2位含9-(1-Prenyl)壬酸和sn-1位含月桂酸、肉豆蔻酸、棕榈酸、硬脂酸、油酸或亚油酸的化合物。放射性磷脂酰胆碱在sn-2位含有[~3H]油酸，在sn-1位含有月桂酸、肉豆蔻酸或棕榈酸。用Sephacryl S-200色谱柱分离供体(脂-载脂蛋白重组)和受体(单层囊泡)的方法，研究了Py标记的脂类转移的动力学和激基缔合物荧光的变化。采用高效疏水色谱柱，以75%异丙醇和25%磷酸三乙基铵(0.15M)为洗脱剂，采用Waters径向压缩C18柱，测定各脂类的保留时间。转运速率常数与保留时间呈线性关系，说明磷脂酰胆碱从脂蛋白和囊泡中的解吸速率主要受疏水作用的控制。对于一系列同源的脂类，可以通过疏水层析获得的保留时间来预测转移速度。1-月桂酰基-2-[9-(1-戊烯基)壬酰基]磷脂酰胆碱在分离的人血清脂蛋白之间的转移动力学显示转移半衰期与供体脂蛋白的大小呈线性相关。因此，从极低密度脂蛋白转移的速度比从高密度脂蛋白转移的速度慢10倍。磷脂转移率与给体的斯托克斯半径和磷脂在疏水柱上的保留时间之间的关系允许计算同源分子在脂蛋白复合体之间的转移率。结果预测，磷脂在血浆脂蛋白之间的自发转移将太慢，不是一个重要的生理现象。
The purpose of this report is to develop a correlation between the hydrophobicity of a phospholipid as measured by reversed-phase high-performance liquid chromatography and its rate of spontaneous transfer and to use this correlation to predict the rate of transfer of any homologous lipid from any lipoprotein. The mechanism of transfer of a series of fluorescent or radiolabeled phospholipids among natural and reassembled serum lipoproteins was studied. Fluorescent phosphatidylcholine included those with 9-(1-pyrenyl)nonanoic acid in the sn-2 position and lauric, myristic, palmitic, stearic, oleic or linoleic acid at sn-1. The radioactive phosphatidylcholines contained [3H]oleic acid in the sn-2 position and lauric, myristic or palmitic acid at sn-1. The kinetics of transfer of the pyrene-labeled lipid were followed by changes in the excimer fluorescence, and that of the radioactive lipids by separation of the donor (lipid-apolipoprotein recombinant) from the acceptor (single bilayer vesicles) on a column of Sephacryl S-200. The retention time of each lipid was measured by high-performance hydrophobic chromatography through a Waters radially compressed C18 column eluted with 75% isopropanol and 25% triethylammonium phosphate (0.15 M). A linear relationship was observed between the rate-constant of transfer and the retention time which suggest that the rate of desorption of phosphatidylcholines from lipoproteins and vesicles is controlled predominately by the hydrophobic effect. For a homologous series of lipids, the rate of transfer can be predicted from retention times obtained from hydrophobic chromatography. The kinetics of transfer of 1-lauroyl-2-[9-(1-pyrenyl)nonanoyl] phosphatidylcholine between isolated human serum lipoproteins exhibits a linear correlation between the transfer half-time and the size of the donor lipoproteins. As a consequence, transfer from very-low-density lipoprotein is 10 times slower than that observed from high-density lipoproteins. The observed correlations between phospholipid transfer rates and both the Stokes radius of the donor and the retention time of the phospholipid on a hydrophobic column permit calculation of the rate of transfer of homologous molecules between lipid-protein complexes. The results predict that the spontaneous transfer of phospholipids between plasma lipoproteins would be too slow to be a physiologically important phenomena.