Studies of the Composition and Structure of Serum Lipoproteins. Isolation and Characterization of Very High Density Lipoproteins of Human Serum^*

Radioimmunoassay of beta lipoprotein—protein of rat serum

“…These methods do not establish the absence of another protein moiety but only the absence of a protein species which will produce a precipitin line when reacted with the antisera utilized. It is possible that one or more proteins are present in our beta Lp-protein preparation in addition to the "B" apoprotein described by other investigators (1,3,15,22,24) which remain associated with "B" apoprotein in all the physicochemical maneuvers utilized, but which might be demonstrated with the proper immunologic system. In fact, Aladjem has shown that appropriate alterations in antigen-antibody proportions will result in the appearance of multiple immunoprecipitant lines with human LDL, and he has summarized the evidence for multiple antigens being present in the LDL protein complement (29).…”

“…The liver has been shown to be the site of synthesis of lipoproteinprotein (1,2,5,7,19,20 (24). Purification of the iodinated lipoprotein by gel filtration provides a rapid method of removing denatured labeled protein from the preparation based on the estimated molecular weight of beta lipoprotein of 2,300,000 (25) and on the experience of previous investigators with gel filtration of serum lipoproteins (26,27).…”

Isolation and partial characterization of apolipoprotein D: A new protein moiety of the human plasma lipoprotein system

“…Under such experimental conditions, the 'thinline' polypeptide appears as a characteristic thin precipitin line nearer the antigen well, while the major precipitin band due to LP-A is closer to the antibody well [9,11]. The occurrence of 'thin-line' polypeptide has also been demonstrated in LDL [11] and VHDL [ 12]. On 7% polyaerylamide gel electrophoresis, the 'thin-line' polypeptide migrates into the region between the A-II and C-II polypeptides [ 10].…”

A lipoprotein characterizing obstructive jaundice. I. Method for quantitative separation and identification of lipoproteins in jaundiced subjects

“…The immunochemical properties of lipoproteins were studied by double diffusion (39) and immunoelectrophoresis (40) in 1% agar or 1% agarose gels employing barbital buffer, pH 8.6, ionic strength 0.05. Plates were developed and stained as previously described (41,42).…”