Son Y S, Zilversmit D B
Biochim Biophys Acta. 1984 Oct 4;795(3):473-80. doi: 10.1016/0005-2760(84)90175-9.
A protein which inhibits cholesteryl ester and triacylglycerol transfer activities was purified from human lipoprotein-deficient plasma by chromatography on phenyl-Sepharose CL-4B, chromatofocusing, Bio-Gel A-0.5m and hydroxylapatite. The inhibitor is a sialoglycoprotein with molecular weight 32 000 and a relatively broad isoelectric region of 3.9-4.3. The inhibitor suppressed triacylglycerol and cholesteryl ester transfer activities to a similar extent. Apolipoprotein A-I, which was separated from the inhibitor by chromatofocusing chromatography, suppressed triacyglycerol transfer more than cholesteryl ester transfer. The percentage reduction of lipid transfer between lipoproteins by the inhibitor was independent of the concentration of transfer protein but was decreased at higher lipoprotein concentrations. The inhibition was not observed during lipid transfer between liposomes. These results indicate that the inhibitor interacts with substrates rather than with the transfer protein.
通过在苯基琼脂糖凝胶CL - 4B上进行色谱分析、聚焦层析、Bio - Gel A - 0.5m和羟基磷灰石柱层析，从人脂蛋白缺乏血浆中纯化出一种抑制胆固醇酯和三酰甘油转移活性的蛋白质。该抑制剂是一种唾液糖蛋白，分子量为32000，等电区相对较宽，为3.9 - 4.3。该抑制剂对三酰甘油和胆固醇酯转移活性的抑制程度相似。通过聚焦层析从抑制剂中分离出的载脂蛋白A - I对三酰甘油转移的抑制作用比对胆固醇酯转移的抑制作用更强。该抑制剂导致脂蛋白间脂质转移减少的百分比与转移蛋白的浓度无关，但在较高脂蛋白浓度时会降低。在脂质体之间的脂质转移过程中未观察到抑制作用。这些结果表明，该抑制剂与底物相互作用，而非与转移蛋白相互作用。
