A Comparison between HDL Lipoproteins and Apoprotein-Phosphatidylcholine Cenapses

Ayrault-Jarrier, M; Pastier, D.; Burdin, J.; Polonovski, J.

doi:10.1016/b978-0-08-016876-0.50009-8

Cited by 4 publications

(5 citation statements)

References 10 publications

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“…The uniqueness of ApoD among serum apolipoproteins lies, however, in its high content of sugar constituents which account for approximately 18% of its dry weight. In contrast, other apolipoproteins or polypeptides contain less than 10% carbohydrate (Ayrault-Jarrier et al, 1961;Marshall and Kummerow, 1962;Shulmah et al, 1974), The molecular weight of ApoD estimated from the amino acid and carbohydrate analyses was 22 100 in agreement with results reported by Kostner (1974a). This molecular weight was supported by the results of the dodecyl sulfate PAGE experiments.…”

Section: Discussionsupporting

confidence: 79%

Studies on the isolation and partial characterization of apolipoprotein D and lipoprotein D of human plasma

McConathy¹,

Alaupovic²

1976

Biochemistry

160

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This report describes further studies on the characterization of apolipoprotein D (ApoD), a recently recognized human plasma apolipoprotein, and presents results on the isolation and distribution of its lipoprotein form, lipoprotein D (LP-D). ApoD, isolated by a procedure combining hydroxylapatite and Sephadex G-100 column chromatography, migrated on 7% polyacrylamide gel as a single band with a mobility intermediate between those of A-II and C-II polypeptides. On double diffusion and immunoelectrophoresis, ApoD reacted only with antiserum to ApoD. It was characterized by the presence of all common amino acids including half-cystine. The amino terminal acid was blocked. Carbohydrate analysis demonstrated that ApoD is a glycoprotein with glucose, mannose, galactose, glucosamine, and sialic acid accounting for 18% of the dry weight of ApoD. The estimated molecular weight of ApoD IS 22 100. ApoD occurs in the serum as a lipoprotein which was isolated from high density lipoproteins3 by two different chromatographic procedures. In the first procedure, high density lipoproteins3 were treated with neuraminidase and chromatographed on concanavlin A. The retained fraction containing LP-D was purified by hydroxylapatite column chromatography. Alternatively, LP-D was isolated by a procedure combining chromatography of high density lipoproteins3 or whole serum on an immunosorber containing antibodies to ApoD, and hydroxylapatite column chromatography. LP-D displayed a single, symmetrical boundary in the analytical ultracentrifuge and a single band on 7% polyacrylamide gel electrophoresis. When injected into rabbits it produced antisera that reacted only with ApoD. On immunoelectrophoresis LP-D had a mobility different from that of lipoprotein A (LP-A). A direct immunological comparison of LP-D and LP-A showed a reaction of nonidentity. LP-D consists of 65-75% protein and 25-35% lipid. The lipid moiety contains cholesterol, cholesterol ester, triglyceride, and phospholipid. The phospholipid. composition is characterized by a relative high content of lysolecithin and sphingomyelin and a relatively low content of lecithin. We have concluded from these studies that ApoD is a unique apolipoprotein that exists in the form of a distinct lipoprotein family with a macromolecular distribution extending from very low density lipoproteins into very high density lipoproteins, but with a maximum concentration in high density lipoproteins3 and a minimum concentration in high density lipoproteins.

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Section: Discussionsupporting

confidence: 79%

Studies on the isolation and partial characterization of apolipoprotein D and lipoprotein D of human plasma

McConathy¹,

Alaupovic²

1976

Biochemistry

160

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“…Results obtained with lymphocytes isolated from the peripheral blood of 23 normal donors, 29 leukemic patients in relapse, and 30 leukemic patients in remission indicated a marked reduction in the degree of fluorescence polarization (P) of lymphocytes isolated from leukemic patients in relapse as compared to lymphocytes isolated from normal donors or leukemic patients in remission (Table 1). These differences in the P values represent a 30% decrease in the degree of microviscosity of cellular membrane lipids in the leukemic lymphocytes (Table 1).…”

Section: Resultsmentioning

confidence: 99%

“…1-ml samples of plasma. Low density lipoproteins (LDL) and high density lipoproteins (HDL) were isolated from normal serum as described (29). Mixed liposomes were prepared from egg lecithin and cholesterol.…”

Section: Methodsmentioning

confidence: 99%

Decreased microviscosity of membrane lipids in leukemic cells: Two possible mechanisms

Petitou

Tuy

Rosenfeld

et al. 1978

Proc. Natl. Acad. Sci. U.S.A.

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Steady-state fluorescence polarization studies with the fluorescent lipid probe 1,6-diphenyl 1,3,5-hexatriene were done to determine the degree of microviscosity of cellular membrane lipids and serum lipoproteins in human normal donors and leukemic patients. The results show a marked decrease in microviscosity of cellular membrane lipids in both intact lymphocytes and isolated cellular plasma membranes obtained from leukemic patients in clinical relapse as compared to intact lymphocytes and isolated cellular plasma membranes obtained from normal donors and leukemic patients in complete clinical remission. Concomitant to these dynamic changes in cellular membrane lipids, the degree of microviscosity of lipids in the blood serum of leukemic patients in clinical relapse is markedly reduced as compared to serum obtained from normal donors and leukemic patients in complete clinical remission. Moreover, an in vitro incubation of leukemic lymphocytes with normal low density lipoproteins results in an increased microviscosity of cellular membrane lipids. In addition to the interrelation between cellular membrane lipids and serum lipoproteins, plasma membrane vesicles with a high degree of lipid microviscosity were isolated from the blood serum and pleural effusion of leukemic patients in clinical relapse. Such membrane vesicles could not be detected in normal serum. Therefore, we suggest that the two major mechanisms associated with the decreased microviscosity of membrane lipids in human leukemic cells are an abnormal exchange in lipids between the leukemic cell surface membrane and leukemic serum lipoproteins and an exfoliation of plasma membrane vesicles with a high degree of microviscosity from the cell surface of leukemic cells.The dynamic nature of a biological lipid complex can be quantitatively monitored by fluorescence polarization analysis with the aid of the fluorescent hydrocarbon probe 1,6-diphenyl 1,3,5-hexatriene (DPH) (1-7). From the recorded degree of fluorescence polarization, the degree of microviscosity of the analyzed sample can be estimated (8,9). Results obtained with this method have shown that the major parameter that determined the degree of microviscosity of lymphocyte membranes is the molar ratio of cholesterol to phospholipids, the two main lipid components of membranes in mammalian cells (10,11 the main characteristic that determines this dynamic difference originates from a significant decrease in the molar ratio of cholesterol to phospholipids in the plasma membrane lipid core of leukemic lymphocytes (10). Recently, two hypotheses have been advanced to explain these differences between normal and leukemic lymphocytes: exchange of lipids between cellular membranes and serum lipoproteins (1, 17), and exfoliation of plasma membrane vesicles from the leukemic cells with a high ratio of cholesterol to phospholipids (10, 18). Our main interest in the present study was to determine the degree of microviscosity of lymphocyte membrane lipids and of serum lipids in normal donors and leukem...

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“…A-II, C-I, C-II, C-Ill and LP-B* [4][5][6]. An additional antigenic component detected predominantly in HDL [7][8][9][10] has been designated 'thin-line' polypeptide due to its characteristic appearance on double diffusion analyses of HDL with anti-HDL or anti-whole serum. 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].…”

Section: Introductionmentioning

confidence: 99%

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

1973

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A Comparison between HDL Lipoproteins and Apoprotein-Phosphatidylcholine Cenapses

Cited by 4 publications

References 10 publications

Studies on the isolation and partial characterization of apolipoprotein D and lipoprotein D of human plasma

Studies on the isolation and partial characterization of apolipoprotein D and lipoprotein D of human plasma

Decreased microviscosity of membrane lipids in leukemic cells: Two possible mechanisms

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

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