Kelley J L, Alaupovic P
Atherosclerosis. 1976 Jul-Aug;24(1-2):155-75. doi: 10.1016/0021-9150(76)90073-3.
(1) Lipoproteins from the serum of male turkeys maintained on a normal diet were separated by sequential preparative ultracentrifugation into VLDL (d less than 1.006 g/ml), LDL (d = 1.006-1.063 g/ml), HDL (d = 1.063-1.21 g/ml) and VHDL (d greater than 1.21 g/ml). Lipoprotein density classes were characterized by analytical ultracentrifugation, agarose electrophoresis, immunodiffusion and immunoelectrophoresis, and by quantitative determination of protein, lipids and individual phosphatides. (2) HDL were the major density class representing 75% of the total lipoprotein content, LDL accounted for approximately 20% and VLDL for only 3-5% of the total lipoproteins. (3) VLDL were characterized by a relatively low content of glyceride (34%). Cholesterol esters were the major lipid (38%) of LDL, and the phospholipids (26%) of HDL. Glycerides of all major density classes consisted of equal amounts of triglycerides and diglycerides. (4) Phosphatidylcholine was the major phosphatide in all density classes. The composition of phosphatides was very similar in the VLDL and LDL, but it was different in the HDL. The ratio of phosphatidylcholine/sphingomyelin was higher in HDL than in VLDL and LD. (5) Immunological and electrophoretic studies showed that all three major density classes consisted of two lipoprotein families designated, in analogy to the human serum lipoprotein system [1], as LP-A and LP-B. The exception was HDL3 (d = 1.125-1.21 g/ml) which contained only LP-A. (6) ApoB was insoluble in aqueous buffers but could be solubilized after reduction and carboxymethylation. No C- or N-terminal amino acids were released by the usual chemical methods. The carbohydrate moiety of ApoB contained mannose, galactose and galactosamine. (7) ApoA consisted of a non-identical polypeptides designated in analogy to the human polypeptides as A-I and A-II. A-I was the major ApoA polypeptide and had a molecular weight of about 27,000. This polypeptide contained no half cystine, and the aspartic acid as the N-terminal and alanine as the C-terminal amino acids. A-II had a molecular weight of about 10,000, contained no half cystine and had alanine as the C-terminal amino acid. A-II showed no N-terminal amino acid by either dansylation, dinitrophenylation or Edman's procedure. Neither A-I nor A-II contained neutral sugars or hexosamines. (8) Concentrations of polypetides analogous to human ApoC, ApoD and "arginine-rich" polypeptide, if present, were too low for their unequivocal chemical characterization.
(1) 通过连续制备超速离心法将正常饮食饲养的雄性火鸡血清中的脂蛋白分离为极低密度脂蛋白（VLDL，密度小于1.006 g/ml）、低密度脂蛋白（LDL，密度 = 1.006 - 1.063 g/ml）、高密度脂蛋白（HDL，密度 = 1.063 - 1.21 g/ml）和极高密度脂蛋白（VHDL，密度大于1.21 g/ml）。通过分析超速离心、琼脂糖电泳、免疫扩散和免疫电泳，以及通过对蛋白质、脂质和个别磷脂的定量测定来表征脂蛋白密度类别。(2) HDL是主要的密度类别，占脂蛋白总含量的75%，LDL约占20%，VLDL仅占总脂蛋白的3 - 5%。(3) VLDL的甘油酯含量相对较低（34%）。胆固醇酯是LDL的主要脂质（38%），HDL的主要脂质是磷脂（26%）。所有主要密度类别的甘油酯由等量的甘油三酯和甘油二酯组成。(4) 磷脂酰胆碱是所有密度类别的主要磷脂。VLDL和LDL中磷脂的组成非常相似，但HDL中的不同。HDL中磷脂酰胆碱/鞘磷脂的比例高于VLDL和LDL。(5) 免疫学和电泳研究表明，所有三个主要密度类别均由两个脂蛋白家族组成，类似于人类血清脂蛋白系统[1]，命名为LP - A和LP - B。例外的是HDL3（密度 = 1.125 - 1.21 g/ml），其仅包含LP - A。(6) 载脂蛋白B不溶于水性缓冲液，但在还原和羧甲基化后可溶解。常规化学方法未释放出C端或N端氨基酸。载脂蛋白B的碳水化合物部分含有甘露糖、半乳糖和氨基半乳糖。(7) 载脂蛋白A由与人类多肽类似的不同多肽组成，分别命名为A - I和A - II。A - I是主要的载脂蛋白A多肽，分子量约为27,000。该多肽不含半胱氨酸，N端氨基酸为天冬氨酸，C端氨基酸为丙氨酸。A - II分子量约为10,000，不含半胱氨酸，C端氨基酸为丙氨酸。通过丹磺酰化、二硝基苯基化或埃德曼降解法，A - II均未显示出N端氨基酸。A - I和A - II均不含中性糖或己糖胺。(8) 类似于人类载脂蛋白C、载脂蛋白D和“富含精氨酸”多肽的多肽浓度（如果存在）过低，无法进行明确的化学表征。
