Immunochemical Studies on Human Plasma Lipoproteins

Abstract

Some years ago, a series of h u m a n serum lipoproteins, distinguishable b y their h y d r a t e d densities and lipid-protein ratios were recognized and isolated b y ultracentrifugal techniques (1). Certain of these lipoproteins are invariably present in h u m a n serum and the concentrations of these and of others can be q u a n t i t a t i v e l y correlated with disease (2). N o difference in the lipoprotein distribution can be d e m o n s t r a t e d between serum and plasma. T h e purpose of this investigation was to obtain information a b o u t the i m m u n o c h e m i c a l specificity of some of the lipoproteins. MethodsPreparation of Lipoproteinsl.--All lipoproteins, unless it is otherwise indicated, were isolated from pooled plasma. The plasma was obtained from citrated blood which was rejected by the San Francisco Blood Bank because of blood clots, positive serologic tests for syphilis, or because 3 weeks or more had elapsed since it was drawn. Between 8 and 16 pints of blood were used per pool.Low density lipoproteins SI6 and SI13 were isolated by the method of Lindgren et al. (3).The ultracentrifugal homogeneity of similar preparations has been discussed (5). The hydrated density of Ss6 lipoproteins is between 1.03 and 1.04 gm./ml, and that of Sjl3 lipoproteins between 1.015 and 1.03 gm./ml. In Fig. 1 ultracentrifuge records of lot" density lipoprotein preparations are presented3 These lipoproteins were used as immunizing antigens

The Inheritance of High Density Lipoprotein Deficiency (Tangier Disease)*

“…In the T propositi and the There are other data attesting to some heterogeneity of HDL, however. Several subfractions isolated in the ultracentrifuge or by column chromatography have shown differences in metabolic behavior (15,21) and antigenic heterogeneity (22). The HDL protein may also show evidence of dissociation into two components under certain conditions (23).…”

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

“…Immunochemical studies of the major density classes established clearly the antigenic heterogeneity of the human plasma lipoprotein system [1][2][3]. Recent chemical investigations have confirmed these earlier findings and demonstrated the presence of six antigenicalty distinct polypeptides designated as A-I,.…”

Heterogeneity of Plasma High Density Lipoproteins*

“…Finally, although only one major immunochemical study of high density lipoproteins (12) has concluded that they may be antigenically heterogeneous, there are other instances in which more than one form of this lipoprotein would appear to be present (13)(14)(15)(16). Thus, there is both direct and indirect evidence of inhomogeneity among high density lipoproteins.…”