Laplaud P M, Beaubatie L, Rall S C, Maurel D
Laboratorie de Biochimie Médicale, Faculté de Médecine et de Pharmacie, Limoges, France.
J Lipid Res. 1987 Aug;28(8):900-12.
Badger plasma lipoproteins with density 1.006-1.063 g/ml have been subfractionated by means of affinity chromatography on a heparin-Sepharose column, using a modification of the method reported by Weisgraber and Mahley (1980. J. Lipid Res. 21: 316-325). These experiments have provided evidence for the presence of three lipoprotein subfractions hereinafter termed fractions I, II, and III. Fraction I was cholesteryl ester- and phospholipid-rich (ca. 35% and 30% of lipoprotein mass, respectively), and contained apoA-I as its prominent apolipoprotein constituent. In contrast, triglyceride-rich fractions II and III both exhibited a complex apolipoprotein pattern, including apoB-100, apoA-I, and apoE whose amino acid composition and NH2-terminal sequence in the badger are reported. However, fraction III appeared markedly enriched in apoE when compared to fraction II. On polyacrylamide gel electrophoresis, fraction I presented as a spectrum of particles with diameters in the 140-190 A range. In contrast, fraction II migrated as a single band with a diameter of approximately 200 A, and fraction III presented as a single band or a doublet with a diameter of 195-200 A. The respective plasma concentrations and chemical compositions of the three chromatographic fractions were determined at four different dates of the year (i.e., April, August, November, and January), each of which corresponded to a different endocrine status in the badger. Thus hypothyroidism appeared to be associated with an increase in the concentration of fraction I, while the lowering in summer of the plasma level of testosterone correlated well with an increase in the concentration of fraction II. At the same time, the respective proportions of hydrophobic lipids in this latter material modified with an increase of triglycerides. Finally, both the apolipoprotein pattern of fraction III, and the chronologic profile of the successive variations of its concentration, suggest that it could represent a metabolic precursor of fraction II. These results suggest that the respective metabolism of the lipoproteins constituting the three chromatographic fractions could be under control by thyroid and testis secretions, operating via a complex combined regulation of the activities of the enzymes and receptors involved in these metabolic processes.
利用肝素 - 琼脂糖柱上的亲和色谱法，对密度为1.006 - 1.063 g/ml的獾血浆脂蛋白进行了亚分级分离，采用了Weisgraber和Mahley（1980年，《脂质研究杂志》21: 316 - 325）报道方法的一种改进。这些实验为三种脂蛋白亚分级（以下称为I、II和III级分）的存在提供了证据。I级分富含胆固醇酯和磷脂（分别约占脂蛋白质量的35%和30%），并含有载脂蛋白A-I作为其主要载脂蛋白成分。相比之下，富含甘油三酯的II级分和III级分都表现出复杂的载脂蛋白模式，包括载脂蛋白B - 100、载脂蛋白A-I和载脂蛋白E，其在獾中的氨基酸组成和NH2 - 末端序列已有报道。然而，与II级分相比，III级分中载脂蛋白E明显富集。在聚丙烯酰胺凝胶电泳中，I级分呈现为一系列直径在140 - 190 Å范围内的颗粒。相比之下，II级分迁移为一条直径约为200 Å的单带，III级分呈现为一条单带或双峰，直径为195 - 200 Å。在一年中的四个不同日期（即四月、八月、十一月和一月）测定了这三个色谱级分各自的血浆浓度和化学成分，每个日期对应獾的不同内分泌状态。因此，甲状腺功能减退似乎与I级分浓度增加有关，而夏季睾酮血浆水平的降低与II级分浓度增加密切相关。同时，随着甘油三酯增加，后一种物质中疏水脂质的各自比例发生了变化。最后，III级分的载脂蛋白模式及其浓度连续变化的时间序列特征表明，它可能代表II级分的代谢前体。这些结果表明，构成这三个色谱级分的脂蛋白各自的代谢可能受甲状腺和睾丸分泌的控制，通过对参与这些代谢过程的酶和受体活性的复杂联合调节来实现。
