Patsch J R, Gotto A M, Olivercrona T, Eisenberg S
Proc Natl Acad Sci U S A. 1978 Sep;75(9):4519-23. doi: 10.1073/pnas.75.9.4519.
The effects of lipolysis of human plasma very low density lipoprotein (VLDL) on the structure and composition of high density lipoproteins (HDL) have been investigated. Lipolysis was performed in a controlled system in vitro containing VLDL (d less than 1.006 g/ml) and HDL3 (d = 1.125-1.210 g/ml) from human plasma and lipoprotein lipase (EC 3.1.1.34) purified from bovine milk. Lipolysis of VLDL caused profound changes in HDL3. Protein, phospholipid, and cholesterol liberated from VLDL during its lipolysis were transferred to the HDL3 particles. As a consequence of this in vitro transfer, the chemical composition and biophysical properties of HDL3 were substantially altered. The newly formed particles exhibited a flotation rate (F01.20) of 6.7 and a hydrated density of 1.110 g/ml. The chemical composition closely resembled that of native HDL2, and their size was slightly larger than that of the precursor HDL3. When HDL3 and postlipolysis HDL2 were subjected to ultracentrifugation under flotation velocity and equilibrium conditions, both proved to be stable particles. These results, when extrapolated to in vivo conditions, suggest an important metabolic relationship between the levels of circulating VLDL and HDL2 in plasma. This relationship now permits a reasonable explanation for numerous in vivo observations in which the levels of VLDL and HDL2 change reciprocally.
已对人血浆极低密度脂蛋白（VLDL）的脂解作用对高密度脂蛋白（HDL）的结构和组成的影响进行了研究。脂解反应在体外可控系统中进行，该系统含有来自人血浆的VLDL（密度小于1.006 g/ml）和HDL3（密度= 1.125 - 1.210 g/ml）以及从牛乳中纯化的脂蛋白脂肪酶（EC 3.1.1.34）。VLDL的脂解导致HDL3发生深刻变化。VLDL在脂解过程中释放出的蛋白质、磷脂和胆固醇被转移到HDL3颗粒中。由于这种体外转移，HDL3的化学组成和生物物理性质发生了显著改变。新形成的颗粒的漂浮率（F01.20）为6.7，水合密度为1.110 g/ml。其化学组成与天然HDL2非常相似，并且其大小略大于前体HDL3。当HDL3和脂解后的HDL2在漂浮速度和平衡条件下进行超速离心时，两者都被证明是稳定的颗粒。这些结果外推至体内情况时，表明血浆中循环的VLDL水平与HDL2水平之间存在重要的代谢关系。这种关系现在可以对许多体内观察结果做出合理的解释，即在这些观察中VLDL和HDL2的水平呈反向变化。
