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Sloop GD, Pop G, Weidman JJ, St Cyr JA. Apolipoprotein(a) is the Product of a Pseudogene: Implications for the Pathophysiology of Lipoprotein(a). Cureus 2018; 10:e2715. [PMID: 30079281 PMCID: PMC6067813 DOI: 10.7759/cureus.2715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 05/31/2018] [Indexed: 12/03/2022] Open
Abstract
Apolipoprotein(a) [apo(a)] is an apolipoprotein unique to lipoprotein(a) [Lp(a)]. Although it has no known function, Lp(a) is a risk factor for accelerated atherothrombosis. We hypothesize that LPA, the gene which encodes apo(a), is a heretofore unrecognized unprocessed pseudogene created by duplication of PLG, the gene which encodes plasminogen. Unprocessed pseudogenes are genes which were created by duplication of functional genes and subsequently lost function after acquiring various mutations. This hypothesis explains many of the unusual features of Lp(a) and apo(a). Also, this hypothesis has implications for the therapy of elevated Lp(a) and atherothrombosis theory. Because apo(a) is functionless, the diseases associated with elevated levels of Lp(a) are due to its impact on blood viscosity.
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Affiliation(s)
- Gregory D Sloop
- Pathology, Idaho College of Osteopathic Medicine, Meridian, USA
| | - Gheorghe Pop
- Cardiology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands, Nijmegen, NLD
| | | | - John A St Cyr
- Research and Development, Jacqmar, Inc., Minneapolis, USA
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2
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De Spirito M, Brunelli R, Mei G, Bertani FR, Ciasca G, Greco G, Papi M, Arcovito G, Ursini F, Parasassi T. Low density lipoprotein aged in plasma forms clusters resembling subendothelial droplets: aggregation via surface sites. Biophys J 2006; 90:4239-47. [PMID: 16533854 PMCID: PMC1459520 DOI: 10.1529/biophysj.105.075788] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In early phases of atherogenesis, droplets and vesicles accumulate in the subendothelial extracellular space of arterial intima. There is much evidence to suggest that these droplets, ranging between 100 and 400 nm, derive from modified low-density lipoprotein (LDL). In investigations of the formation mechanism of these droplets, LDL fusion was previously induced in vitro by proteolysis, lipolysis, oxidation, and vigorous shaking, but all treatments failed to reproduce the size distribution range of in vivo droplets, mostly resulting, instead, in particles with a diameter intermediate between that of one and two LDL. Our approach was meant to mimic LDL aging in plasma. LDL isolated from plasma that was incubated overnight at 37 degrees C is slightly modified in the secondary structure of its protein component and is primed to form very large aggregates according to a reaction-limited mechanism. This mechanism requires interactions between selected surface sites, whereas massive fusion is ruled out. In the frame of the general theory for colloids, the aggregation of LDL aged in plasma fulfills all the requirements of the reaction-limited mechanism, encompassing 1), exponential growth; 2), fractal structure, with the dimension of elementary constituent still consistent with a single LDL; and 3), extreme polydispersity of aggregates, with shape and dimension very close to that of droplets observed in vivo.
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Affiliation(s)
- Marco De Spirito
- Istituto di Fisica, Facoltà di Medicina e Chirurgia, Università Cattolica del Sacro Cuore, Rome, Italy
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3
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Wang X, Pease R, Bertinato J, Milne RW. Well-defined regions of apolipoprotein B-100 undergo conformational change during its intravascular metabolism. Arterioscler Thromb Vasc Biol 2000; 20:1301-8. [PMID: 10807746 DOI: 10.1161/01.atv.20.5.1301] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Apolipoprotein B (apoB)-100-containing lipoproteins are secreted from the liver as large triglyceride-rich very low density lipoproteins (VLDLs) into the circulation, where they are transformed, through the action of lipases and plasma lipid transfer proteins, into smaller, less buoyant, cholesteryl ester-rich low density lipoproteins (LDLs). As a consequence of this intravascular metabolism, apoB-containing lipoproteins are heterogeneous in size, in hydrated density, in surface charge, and in lipid and apolipoprotein composition. To identify specific regions of apoB that may undergo conformational changes during the intravascular transformation of VLDLs into LDLs, we have used a panel of 29 well-characterized anti-apoB monoclonal antibodies to determine whether individual apoB epitopes are differentially expressed in VLDL, intermediate density lipoprotein (IDL), and LDL subfractions isolated from 6 normolipidemic subjects. When analyzed in a solid-phase radioimmunoassay, the expression of most epitopes was remarkably similar in VLDLs, IDLs, and LDLs. Two epitopes that are close to the apoB LDL receptor-binding site show an increased expression in large (1.019 to 1.028 g/mL), medium (1.028 to 1.041 g/mL), and small (1.041 to 1.063 g/mL) LDLs compared with VLDLs and IDLs, and 2 epitopes situated between apoB residues 4342 and 4536 are significantly more immunoreactive in small and medium-sized LDLs compared with VLDLs, IDLs, and large LDLs. Therefore, as VLDL is converted to LDL, conformational changes identified by monoclonal antibodies occur at precise points in the metabolic cascade and are limited to well-defined regions of apoB structure. These conformational changes may correspond to alterations in apoB functional activities.
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Affiliation(s)
- X Wang
- Lipoprotein and Atherosclerosis Research Group, Departments of Pathology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
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4
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Breyer ED, Le NA, Li X, Martinson D, Brown WV. Apolipoprotein C-III displacement of apolipoprotein E from VLDL: effect of particle size. J Lipid Res 1999. [DOI: 10.1016/s0022-2275(20)34904-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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5
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Ilmonen M, Knudsen P, Taskinen MR, Tikkanen MJ. Genetic variation in the amino-terminal part of apolipoprotein B: studies in hyperlipidemic patients. Atherosclerosis 1998; 138:367-74. [PMID: 9690921 DOI: 10.1016/s0021-9150(98)00038-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hypertriglyceridemia is a heterogeneous lipid disorder often running in families. Variation in the apolipoprotein B (apo B) gene has been associated with serum triglyceride levels. Recently, a role of the amino-terminal end of apo B in binding with lipoprotein lipase (LPL) has been suggested. We screened the 5' end of the apo B gene in 76 Finnish severely hypertriglyceridemic (> 6 mmol/l) patients, using a single-strand conformation polymorphism (SSCP) screening method. We detected a previously unreported polymorphic C2316-->A change, causing a Val703-->Ile substitution. The minor 703 Ile allele frequency was 0.04 in hypercholesterolemic and normolipidemic population samples. This allele was associated with lower serum triglyceride levels in a normolipidemic population sample. Analysis of two previously reported polymorphisms also located in the amino-terminal domain of apo B (Thr71-->Ile and Val591-->Ala) revealed elevating effects on serum apo B concentrations in hypertriglyceridemic individuals. The 591 Ala allele was associated with elevated apo B (P=0.011), and individuals with both minor alleles (apo B 591 Ala + and apo B 71 Ile +) had higher apo B levels compared to subjects homozygous for both common alleles (P=0.004). Although no DNA sequence change seemed to be the cause of hypertriglyceridemia in our patients, genetic variation in the 5' end of the apo B gene may contribute to changes in serum apo B levels in hypertriglyceridemic patients.
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Affiliation(s)
- M Ilmonen
- Department of Medicine, Helsinki University Central Hospital, Finland
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6
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Viens L, Lagrost L. Effect of lipid transfer activity and triglyceride hydrolysis on apolipoprotein B immunoreactivity in modified low density lipoproteins. J Lipid Res 1997. [DOI: 10.1016/s0022-2275(20)37195-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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7
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Shige H, Ishikawa T, Ikewaki K, Nishiwaki M, Higashi K, Nakajima K, Nakamura H. Remnant-like very-low-density lipoprotein isolated from hypertriglyceridemic patients by immunoaffinity chromatography suppressed 3-hydroxy-3-methylglutaryl coenzyme A activity of cultured human skin fibroblasts. Clin Chim Acta 1997; 258:145-58. [PMID: 9074812 DOI: 10.1016/s0009-8981(96)06469-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
It has been previously reported that VLDL unbound to monoclonal antibody against apoB-100 was rich in apoE, thus resembling remnant particles (J Lipid Res, 1993:33;369-380). In the current study, we have further analyzed the unbound VLDL fraction in plasma from hypertriglyceridemic patients using a mixture of monoclonal antibodies against apoB-100 and apoA-1. The unbound VLDL isolated from the plasma of hypertriglyceridemic patients was found to be rich in apoE, apoB-48, and triglyceride compared with the bound VLDL. Furthermore, these unbound VLDL, but not bound VLDL, significantly suppressed HMG CoA reductase activity of cultured human skin fibroblasts (-20 to -25%, P = 0.0022). The degree of suppression is significantly correlated with the apoE content of unbound VLDL (r = -0.769, P < 0.05). Unbound VLDL failed to suppress the activity of HMG CoA reductase of LDL receptor negative fibroblasts. These observations indicate a potential atherogenicity of remnant-like unbound VLDL by delivering more cholesterol through the LDL receptor dependent pathway with apoE as a ligand. In conclusion, this new immunoaffinity chromatography system is a useful method for directly quantifying atherogenic remnants in plasma.
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Affiliation(s)
- H Shige
- First Department of Internal Medicine, National Defense Medical College, Saitama, Japan
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8
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Chen GC, Liu W, Duchateau P, Allaart J, Hamilton RL, Mendel CM, Lau K, Hardman DA, Frost PH, Malloy MJ. Conformational differences in human apolipoprotein B-100 among subspecies of low density lipoproteins (LDL). Association of altered proteolytic accessibility with decreased receptor binding of LDL subspecies from hypertriglyceridemic subjects. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)62020-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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9
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Nakajima K, Saito T, Tamura A, Suzuki M, Nakano T, Adachi M, Tanaka A, Tada N, Nakamura H, Campos E. Cholesterol in remnant-like lipoproteins in human serum using monoclonal anti apo B-100 and anti apo A-I immunoaffinity mixed gels. Clin Chim Acta 1993; 223:53-71. [PMID: 8143370 DOI: 10.1016/0009-8981(93)90062-9] [Citation(s) in RCA: 337] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have developed a simple, rapid assay method for apo E-rich lipoproteins (d < 1.006 g/ml), using an immunoaffinity gel mixture of anti apo B-100 and apo A-I antibodies coupled to Sepharose 4B. The immunoaffinity mixed gels adsorb normal lipoproteins containing apo A-I quantitatively as well as most lipoproteins containing apo B-100. Unbound lipoproteins are quantified by assay of cholesterol. Characterization of the unbound lipoproteins of d < 1.006 g/ml (J Lipid Res 1992; 33: 369-380) has shown that they represent chylomicron and VLDL remnant-like particles (RLP). RLP-Cholesterol(C) levels in plasma have been determined in 363 male and female normolipidemic subjects (mean +/- S.D.: 72 +/- 16 mg/l) and have been found to be higher in patients with coronary heart disease and familial dysbetalipoproteinemia. Triglyceride-rich lipoproteins may well contain both atherogenic and non-atherogenic particles that can be separated by this simple immunoadsorption assay.
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Affiliation(s)
- K Nakajima
- Japan Immunoresearch Laboratories, Gunma
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10
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Immunological properties of apoB-containing lipoprotein particles in human atherosclerotic arteries. J Lipid Res 1993. [DOI: 10.1016/s0022-2275(20)39693-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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11
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Harduin P, Tailleux A, Fruchart JC, Fievet C. Modulation of the expression of human LDL-Apo B-100 epitopes by lipids and apolipoproteins. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1993; 13:529-35. [PMID: 7682107 DOI: 10.1161/01.atv.13.4.529] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The purpose of the present study was to determine the immunochemical properties of apolipoprotein (apo) B-100 associated with low density lipoprotein (LDL) in relation to lipid and apolipoprotein composition. LDLs were isolated by sequential ultracentrifugation (1.019 < d < 1.050 g/mL) from two healthy volunteers and 21 dyslipidemic patients to obtain heterogeneous samples of LDL. Lipid (free cholesterol, cholesteryl esters, triglycerides, and phospholipids) and apolipoprotein contents (apo B, apo C-III, apo E) were determined in each LDL sample. Immunoreactivities of apo B were tested in solid-phase competitive-binding radioimmunoassays using seven monoclonal anti-LDL antibodies that reacted with defined epitopes of apo B-100. The relation between lipid and/or protein variables and the immunoreactivity of apo B was evaluated by successive use of Spearman's rank simple correlation, partial correlation, and canonical correlation analyses. The canonical correlation analysis showed that apo B-100 immunoreactivity on LDL is highly dependent on lipid and apolipoprotein composition simultaneously. The results confirmed the influence of surface and core lipids on the expression of the apo B-100 epitopes, independent of their location on the molecule. However, the lipid requirement of LDL strongly influences the expression of epitopes mapped in the LDL receptor-recognition domain. In contrast to apo E, apo C-III does not seem to influence the expression of the apo B-100 epitopes in the LDL range studied.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P Harduin
- Serlia et Institut National de la Santé et de la Recherche Médicale (INSERM) U325, Institut Pasteur, Lille, France
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12
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Brasaemle DL, Cornely-Moss K, Bensadoun A. Hepatic lipase treatment of chylomicron remnants increases exposure of apolipoprotein E. J Lipid Res 1993. [DOI: 10.1016/s0022-2275(20)40737-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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13
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Chan L. Apolipoprotein B, the major protein component of triglyceride-rich and low density lipoproteins. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)35646-1] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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14
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Liu M, Krul E, Subbaiah P. Effect of apoprotein B conformation on the activation of lysolecithin acyltransferase and lecithin: cholesterol acyltransferase. Studies with subfractions of low density lipoproteins. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42742-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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15
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Chen G, Lau K, Hamilton R, Kane J. Differences in local conformation in human apolipoprotein B-100 of plasma low density and very low density lipoproteins as identified by cathepsin D. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98938-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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16
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Wagner RD, Krul ES, Tang J, Parhofer KG, Garlock K, Talmud P, Schonfeld G. ApoB-54.8, a truncated apolipoprotein found primarily in VLDL, is associated with a nonsense mutation in the apoB gene and hypobetalipoproteinemia. J Lipid Res 1991. [DOI: 10.1016/s0022-2275(20)41997-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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17
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Kunitake ST, Young SG, Chen GC, Pullinger CR, Zhu S, Pease RJ, Scott J, Hass P, Schilling J, Kane JP. Conformation of apolipoprotein B-100 in the low density lipoproteins of tangier disease. Identification of localized conformational response to triglyceride content. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)45278-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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18
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Fielding CJ, Castro GR, Donner C, Fielding PE, Reaven GM. Distribution of apolipoprotein E in the plasma of insulin-dependent and noninsulin-dependent diabetics and its relation to cholesterol net transport. J Lipid Res 1990. [DOI: 10.1016/s0022-2275(20)38764-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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19
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Jaakkola O, Solakivi T, Ylä-Herttuala S, Nikkari T. Receptor-mediated binding and degradation of subfractions of human plasma low-density lipoprotein by cultured fibroblasts. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 1005:118-22. [PMID: 2775766 DOI: 10.1016/0005-2760(89)90176-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The receptor-mediated metabolism of human plasma low-density lipoprotein (LDL) subfractions was studied. LDL was isolated from healthy donors and further fractionated by density gradient ultracentrifugation into three subfractions: (I) d = 1.031-1.037, (II) d = 1.037-1.041 and (III) d = 1.041-1.047 g/ml, comprising 24 +/- 7%, 46 +/- 8% and 30 +/- 9% of the total LDL protein, respectively. As assessed by electron microscopy and gradient gel electrophoresis, the LDL particle size decreased and the relative protein content increased from fraction I towards fraction III. Fraction II had the highest (Kd 2.6 micrograms/ml) and fraction I the lowest (Kd 5.8 micrograms/ml) binding affinity to LDL receptors of human fibroblasts at 4 degrees C. The rate of receptor-mediated degradation of fraction II was also higher than that of the other two fractions at 37 degrees C. These results suggest that LDL subfractions have different rates of receptor-mediated catabolism depending on particle size or composition, and therefore their metabolic fate and atherogenic properties may also differ.
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Affiliation(s)
- O Jaakkola
- Department of Biomedical Sciences, University of Tampere, Finland
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20
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Evaluation of a monoclonal antibody-based enzyme-linked immunosorbent assay as a candidate reference method for the measurement of apolipoprotein B-100. J Lipid Res 1989. [DOI: 10.1016/s0022-2275(20)38265-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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21
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22
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Apolipoprotein E Mediates Binding of Normal Very Low Density Lipoprotein to Heparin but Is Not Required for High Affinity Receptor Binding. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)63881-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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23
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Marcel YL, Hogue M, Weech PK, Davignon J, Milne RW. Expression of apolipoprotein B epitopes in lipoproteins. Relationship to conformation and function. ARTERIOSCLEROSIS (DALLAS, TEX.) 1988; 8:832-44. [PMID: 2461695 DOI: 10.1161/01.atv.8.6.832] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The immunochemical properties of apolipoprotein (apo) B have been studied in very low density lipoprotein (VLDL)1 (Sf 100 to 400), VLDL2 (Sf 60 to 100), VLDL3 (Sf 20 to 60), different intermediate density lipoprotein (IDL), and low density lipoprotein (LDL) subfractions isolated from patients with type IV hypertriglyceridemia. In these lipoproteins, we characterized the association of apo B with other apolipoproteins and the expression and immunoreactivity of several apo B epitopes close to the apo B receptor binding sites (3F5, 4G3, 3A8, and 5E11) and of other epitopes located on the apo B100-B48 common region (1D1 and 2D8). Immunoprecipitation showed that the proportion of lipoprotein particles expressing each apo B epitope increased from VLDL1 to LDL2; this was more apparent with 3A8 and 5E11 than with 3F5. The VLDL that were negative for apo E epitopes (60% or more of the total) were enriched in apo C. The lipoprotein particles containing apo E and/or apo C-III decreased progressively from VLDL1 (30% and 85%, respectively) to LDL2 (10% and 25%, respectively). Similar observations were made for apo C-I and apo D, demonstrating that apolipoprotein heterogeneity is greatest in the lightest lipoproteins. By competitive radioimmunoassay, the epitope for 4G3 was equally immunoreactive in each lipoprotein subclass, and the affinity constant (Ka) of 4G3 for different lipoproteins showed little variation. In contrast, both immunoreactivity and Ka of 3A8 and 5E11 increased progressively and significantly with the increasing density of the lipoprotein subclasses. This phenomenon is correlated with the increasing binding affinity of apo B in these lipoprotein subclasses to the LDL receptor of fibroblasts. We conclude that, as the apo B-containing lipoproteins become smaller, the conformation of specific regions of apo B is modified: in the receptor binding domain, the conformation of epitope 4G3, which is mapped between residues 2980 and 3080, remains constant, while that of 3A8 and 5E11 (residues 3441 to 3568) changes progressively. We propose the theory that the change in conformation in the domain spanning residues 3441 and 3568 allows the maximum expression of epitopes 3A8 and 5E11 and of the receptor binding site.
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Affiliation(s)
- Y L Marcel
- Laboratory of Lipoprotein Metabolism, Clinical Research Institute, Montreal, Quebec, Canada
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24
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Krul ES, Tikkanen MJ, Schonfeld G. Heterogeneity of apolipoprotein E epitope expression on human lipoproteins: importance for apolipoprotein E function. J Lipid Res 1988. [DOI: 10.1016/s0022-2275(20)38434-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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25
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26
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Luyeye I, Fievet C, Dupont JC, Durieux C, Slimane N, Lecocq JF, Demarquilly C, Fruchart JC. Human apolipoprotein B. Evidence for its immunochemical heterogeneity using monoclonal antibodies and an immunoenzymometric assay. Clin Biochem 1988; 21:255-61. [PMID: 2457462 DOI: 10.1016/s0009-9120(88)80010-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Predefined monoclonal antibodies (Mabs) were used in an immunoenzymometric assay to study the immunochemical heterogeneity of lipoproteins and to search for potential epitopes with pathological importance. By measuring apolipoprotein B (apo B) epitopes in patients with and without angiographically documented coronary artery disease and in patients with type IIa hyperlipoproteinemia, we have found that both types of patients have a significant increase in Apo B-containing particles specifically recognized by one Mab (BL3). We have also observed that the effects of fenofibrate on type IIa patients vary greatly depending on the plasma concentrations of various Apo B-containing lipoproteins. The greatest effects occurred in patients with epitopes recognized by BL3. Lastly, by sequential precipitation of specific epitopes by BL3, we have obtained evidence that the residual epitope(s) may be related to one or more lipoprotein particles.
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Affiliation(s)
- I Luyeye
- Service de Recherche sur les Lipoproteines et l'Athérosclérose, Institut Pasteur, Lille, France
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27
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Leowsky J, James RW, Taton J, Pometta D. The influence of metabolic control on very low density lipoprotein composition in hypertriglyceridemic type II diabetics. A study using heparin-sepharose chromatography. Metabolism 1988; 37:721-6. [PMID: 3405088 DOI: 10.1016/0026-0495(88)90004-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The composition and heparin-binding capacity of very low density lipoproteins (VLDL) from type II diabetics prone to develop secondary hypertriglyceridemia have been examined. Twelve diabetic patients whose triglyceride levels normalized during short-term treatment for hyperglycemia were studied. Normalization of triglyceride values reduced plasma levels of VLDL without modifying its relative lipid composition. There was, however, an increase in its relative apoprotein (apo) content, to which apo B made a greater percentage contribution. The calculated average particle diameter of posttreatment VLDL was reduced. The fraction of VLDL binding to heparin increased after treatment. Binding was strongly correlated to the apo B content and, to a lesser extent, to the apo E content. The data suggest that treatment of hyperglycemia favorably modified VLDL such that they more closely resemble VLDL from normolipidemic subjects, with potentially beneficial physiological consequences.
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Affiliation(s)
- J Leowsky
- Department of Internal Diseases and Diabetology, Warsaw Medical School, Poland
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28
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Krul ES, Kleinman Y, Kinoshita M, Pfleger B, Oida K, Law A, Scott J, Pease R, Schonfeld G. Regional specificities of monoclonal anti-human apolipoprotein B antibodies. J Lipid Res 1988. [DOI: 10.1016/s0022-2275(20)38475-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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29
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Kleinman Y, Krul ES, Burnes M, Aronson W, Pfleger B, Schonfeld G. Lipolysis of LDL with phospholipase A2 alters the expression of selected apoB-100 epitopes and the interaction of LDL with cells. J Lipid Res 1988. [DOI: 10.1016/s0022-2275(20)38488-1] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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30
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Gherardi E, Hutchings A, Galfre G, Bowyer DE. Rat monoclonal antibodies to rabbit and human serum low-density lipoprotein. Biochem J 1988; 252:237-45. [PMID: 2458711 PMCID: PMC1149129 DOI: 10.1042/bj2520237] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A total of 16 hybrid myeloma clones secreting monoclonal antibodies (McAb) to rabbit or human serum low-density lipoprotein (LDL) were derived from the fusion of spleen cells from LOU or DA rats immunized with rabbit or human LDL and the rat myeloma lines Y3 Ag1.2.3 or YB2/0. Anti-(rabbit LDL) McAb showed limited reactivity with LDL from human, rhesus-monkey, rat and mouse serum. Six out of seven anti-(human LDL) McAb reacted with rhesus-monkey LDL, and only one showed partial cross-reaction with rabbit LDL. Binding-competition experiments indicated that the epitopes recognized by the anti-(rabbit LDL) IgG could be grouped into two major clusters: McAb in the first cluster reacted either with apo-(lipoprotein B-100) (apoB-100) and apo-(lipoprotein B-74) (apoB-74) or with apoB-100 but not with apo-(lipoprotein B-48) (apoB-48), the lower-Mr form of apoB of intestinal origin; the McAb in the second cluster all reacted with apoB-48 in addition to apoB-100 or apoB-100 and apoB-74. The six anti-(human LDL) IgG bound to separate epitopes on LDL. Further data on the epitope specificity of these McAb were obtained by antibody blotting after partial proteolysis of apoB-100 with trypsin or staphylococcal V8 proteinase, and the data confirmed the results obtained with the binding-competition experiments. One McAb to rabbit LDL inhibited the binding of LDL to the fibroblast LDL receptor (50% inhibition at a McAb/LDL molar ratio of 10). A similar result was produced by two other McAb at higher concentrations of antibody.
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Affiliation(s)
- E Gherardi
- Department of Pathology, University of Cambridge, U.K
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31
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Characterization of two lipoproteins containing apolipoproteins B and E from lesion-free human aortic intima. J Lipid Res 1988. [DOI: 10.1016/s0022-2275(20)38503-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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32
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Ishikawa Y, Fielding CJ, Fielding PE. A change in apolipoprotein B expression is required for the binding of apolipoprotein E to very low density lipoprotein. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)69131-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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33
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Shepherd J, Packard CJ. Lipid transport through the plasma: the metabolic basis of hyperlipidaemia. BAILLIERE'S CLINICAL ENDOCRINOLOGY AND METABOLISM 1987; 1:495-514. [PMID: 3330420 DOI: 10.1016/s0950-351x(87)80021-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Plasma lipid abnormalities derive their importance from their association with coronary artery disease. Elevated cholesterol levels accentuate risk, and clinical trials have shown that reductions lead to a decline in coronary events. The major plasma lipids, cholesterol and triglyceride, circulate in association with specific proteins as lipid-protein or lipoprotein complexes. The proteins direct and regulate the metabolism of these complexes by interacting with tissue enzymes and receptors. The metabolic fate of circulating triglyceride is governed by the activity of the enzyme lipoprotein lipase, situated in adipose tissue and skeletal muscle. Cellular demand for cholesterol, on the other hand, is met by activation of a specific receptor which mediates the delivery of sterol-rich lipoproteins to lysosomal degradation in liver and peripheral tissues. In order to prevent excess cholesterol accumulation at the periphery, there is a system of reverse cholesterol transport which involves assimilation and trapping of the sterol in the plasma lipoproteins through the action of the enzyme lecithin:cholesterol acyltransferase. Thereafter, the cholesterol is delivered to the liver, the only organ capable of excreting it in significant amounts. Disturbances in these processes may produce gross changes in the plasma lipid profile, clearly recognizable as hyperlipidaemia. However, it is becoming increasingly clear that a number of inherited traits can subtly perturb the lipoprotein spectrum and increase coronary risk even in subjects whose plasma lipoprotein profile would be considered normal.
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34
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Kissebah AH. Low density lipoprotein metabolism in non-insulin-dependent diabetes mellitus. DIABETES/METABOLISM REVIEWS 1987; 3:619-51. [PMID: 3301236 DOI: 10.1002/dmr.5610030302] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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35
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Poapst M, Uffelman K, Steiner G. The chromogenicity and quantitation of apoB-100 and apoB-48 of human plasma lipoproteins on analytical SDS gel electrophoresis. Atherosclerosis 1987; 65:75-88. [PMID: 3606734 DOI: 10.1016/0021-9150(87)90009-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
ApoB-100 and apoB-48 may be readily resolved in 3.3% sodium dodecyl sulphate-polyacrylamide gels. This study has characterized the relative chromogenicities (staining intensity/micrograms protein) of human apoB-100 and apoB-48 in various lipoprotein classes with Coomassie Brilliant Blue (R250) upon SDS-PAGE. The relation between dye uptake and the mass of each apoB species in any lipoprotein preparation, was linear at least within the concentration range of total apoprotein B which is optimally resolved in these gels (20-50 micrograms total apoprotein B), and was a function of the density of the particular lipoprotein fraction under investigation. There was a constant and characteristic difference between the chromogenicity for apoB-100 and that for apoB-48 as determined from the slopes of their respective chromogenicity curves. The slope of the lines describing staining intensity vs. protein mass for both apoB-100 and apoB-48 decreased as the density of the lipoprotein fraction increased. The slope of the line for apoB-100 was steeper than that for apoB-48 (i.e. chromogenicity apoB-100 greater than apoB-48) in all lipoprotein fractions where both were present. The relationship between the slopes of the lines for apoB-100 and apoB-48 was constant regardless of the density of the lipoprotein fraction. The chromogenicity curves for apoB-100 and for apoB-48 obtained when lipoprotein samples were applied to gels in concentrations conventionally used for this technique (i.e. 20-100 micrograms total apoB/gel) did not extrapolate to the same point on the ordinate, which precludes the use of a simple ratio or "chromogenicity factor" to describe their relative chromogenicities over this concentration range, Hence, a novel approach was developed to determine the relative mass of apoB-100/apoB-48 in lipoprotein samples, based on their staining characteristics in SDS-PAGE.
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36
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Kleinman Y, Schonfeld G, Gavish D, Oschry Y, Eisenberg S. Hypolipidemic therapy modulates expression of apolipoprotein B epitopes on low density lipoproteins. Studies in mild to moderate hypertriglyceridemic patients. J Lipid Res 1987. [DOI: 10.1016/s0022-2275(20)38671-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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37
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Milne RW, Blanchette L, Théolis R, Weech PK, Marcel YL. Monoclonal antibodies distinguish between lipid-dependent and reversible conformational states of human apolipoprotein B. Mol Immunol 1987; 24:435-47. [PMID: 2443835 DOI: 10.1016/0161-5890(87)90017-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Monoclonal antibodies (MAbs) have been prepared against apolipoprotein (apo) B which had been delipidated and resolubilized (apo Bsol). The MAbs were classified into nine groups according to their behavior in competitive binding assays and, following SDS electrophoresis and immunoblots, their corresponding epitopes were assigned to apo B48, apo B74, apo B26 and to fragments of LDL apo B (apo BLDL) generated by limited tryptic proteolysis. In addition to their reactivity with soluble apo B all antibodies also reacted with LDL which had been adsorbed to polystyrene. Competitive binding of MAbs to insolubilized antigen also indicated conformational similarities between apo Bsol and apoBLDL. These similarities were, however, less apparent when the respective antigens were in solution. In competitive radioimmunoassays the majority of anti-apo Bsol MAbs reacted better with apo Bsol than with LDL although the opposite was true for one group of MAbs. In immunoprecipitation studies the MAbs which preferentially recognize apo BLDL could precipitate 95% of 125I-LDL whereas the immunoprecipitation with those MAbs which preferentially recognize soluble apo B varied between 0 and 95%. Between 65 and 82% of 125I-apo Bsol was immunoprecipitated under the same conditions. Thus, epitopes defined by MAbs prepared against apo Bsol may be expressed on apo BLDL when it is adsorbed to plastic but not necessarily when it is in solution. For those epitopes preferentially expressed on apo BLDL, reincorporation of soluble apo B into phospholipid-cholesteryl ester microemulsions or phospholipid-cholesterol liposomes increased their immunoreactivity, whereas, the reincorporation of apo B into lipid vesicles resulted in a decreased reactivity with those MAbs which recognized better apo Bsol than apo BLDL. Thus, while the respective conformations of apo Bsol and apo BLDL are only partially similar, they can be reversibly interchanged by delipidation and relipidation.
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Affiliation(s)
- R W Milne
- Clinical Research Institute of Montreal, Quebec, Canada
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38
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Wong L, Gadams NM. Immunological heterogeneity of rat apolipoprotein B epitope expression. A study using monoclonal antibodies to rat apolipoprotein B. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 918:16-26. [PMID: 2435323 DOI: 10.1016/0005-2760(87)90004-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Epitope expression of rat apolipoprotein B on lipoproteins was investigated with the help of six monoclonal antibodies produced from mice. Through a variety of techniques, which include cotitrations, ELISAs and quantitative immunoadsorption precipitation, we concluded that the six monoclonal antibodies recognize five different epitopes. LRB 110 and LRB 260 recognize epitopes that may be overlapping. LRB 240 and LRB 250 recognize epitopes that are preferentially expressed in triacylglycerol-rich particles. LRB 220 recognizes an epitope that is expressed by all apolipoprotein-B-containing lipoproteins. We have also determined that apolipoprotein B epitope expression in rat lipoproteins is very similar to its human counterpart. Both rat and human apolipoprotein B epitope expression on lipoproteins showed heterogeneities even in homologous lipoprotein preparations. We concluded that a variety of techniques are necessary to fully characterize monoclonal antibodies to apolipoproteins. The possible implications of epitope expression in pathophysiology are also discussed.
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39
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Milne RW, Weech PK, Marcel YL. Heterogeneity of apolipoprotein B containing lipoproteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1987; 210:1-5. [PMID: 2438908 DOI: 10.1007/978-1-4684-1268-0_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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41
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Delpierre C, Martin C, Gesquiere JC, Tartar A, Cachera C, Puchois P, Fievet C, Fruchart JC. Chemical approach to synthetic immunogens in clinical chemistry. INTERNATIONAL JOURNAL OF RADIATION APPLICATIONS AND INSTRUMENTATION. PART B, NUCLEAR MEDICINE AND BIOLOGY 1987; 14:281-8. [PMID: 3654252 DOI: 10.1016/0883-2897(87)90004-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- C Delpierre
- Service de Chimie des Biomolécules, Institut Pasteur de Lille
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42
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Parallel expression of the MB19 genetic polymorphism in apoprotein B-100 and apoprotein B-48. Evidence that both apoproteins are products of the same gene. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)35734-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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43
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Riesen WF, Sturzenegger E, Imhof C, Mordasini R. Quantitation of apolipoprotein B by polyclonal and monoclonal antibodies. Clin Chim Acta 1986; 154:29-40. [PMID: 2417757 DOI: 10.1016/0009-8981(86)90085-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A non-competitive sandwich enzyme linked immunosorbent assay for the quantitation of apolipoprotein B with polyclonal and monoclonal antibodies was developed. Polyclonal antibodies were used as 'coater'. In the assay with polyclonal antibodies, the same antibody was used as conjugate with alkaline phosphatase. For studies with monoclonal antibodies, enzyme conjugated anti-mouse immunoglobulin had to be used, since monoclonal antibodies lost their reactivity upon enzyme conjugation. Two murine monoclonal antibodies were employed: MAB B-1 with specificity for apolipoproteins (Apo) B-48 and B-100 and MAB B-5 with specificity for B-100 (Radioimmunoassay Inc.). In a reference group Apo B values of 0.82 +/- 0.20 g/l were measured with polyclonal antibodies, 0.68 +/- 0.19 g/l and 0.95 +/- 0.33 g/l with MAB B-1 and MAB B-5. In pure hypercholesterolemia, a similar increase was found with all three antibodies, while in combined hyperlipoproteinemia MAB B-5 gave greater than 40% lower values. Differences were also found with respect to the correlation between Apo B and cholesterol or triglycerides.
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44
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45
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Krul ES, Tikkanen MJ, Cole TG, Davie JM, Schonfeld G. Roles of apolipoproteins B and E in the cellular binding of very low density lipoproteins. J Clin Invest 1985; 75:361-9. [PMID: 3973009 PMCID: PMC423494 DOI: 10.1172/jci111708] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Apoproteins B and E both interact with cellular low density lipoprotein (LDL) apolipoprotein B and E (apo B,E)-receptors, and very low density lipoproteins (VLDL) contain both apo B and apo E. Our aim was to study the relative importance of apo B and apo E in the binding of VLDL subfractions to cells. Two monoclonal anti-LDL-apo B antibodies (464B1B3 and 464B1B6, 2a and 2b, respectively) and two anti-apo E antibodies (1506 A1.4 and 1907 F6.4) were used to inhibit lipoprotein-cell interactions. In confirmation of previous findings, the binding and degradation of 125I-LDL by human fibroblasts were inhibited approximately 90% by antibodies 2a or 2b or the antigen-binding fragments of 2a, whereas the cellular processing of 125I-VLDL3 (Sf20-60), 125I-VLDL2 (Sf60-120), and 125I-VLDL1 (Sf greater than 120) were inhibited by only approximately 50%, approximately 25%, and less than 10%, respectively. The VLDL1-3 and LDL-dependent intracellular esterification of cholesterol with [3H]oleate were inhibited to a similar extent. Other monoclonal anti-human apo B antibodies inhibited lipoprotein-cell interactions much less effectively and nonimmune IgG isolated from mouse serum did not inhibit at all. 20-fold excesses of LDL produced about the same patterns of inhibition of degradation of 125I-VLDL1-3 and LDL by cells as did antibodies 2a and 2b, whereas homologous unlabeled VLDL1-3 in like amounts inhibited the matched 125I-VLDL subfraction more effectively. Two anti-apo E monoclonal antibodies and a polyclonal anti-apo E antibody inhibited cell-mediated degradation of and lipoprotein-dependent cholesterol esterification by VLDL1 but not VLDL3 or LDL. The results suggest that receptor recognition sites on apo E in preference to sites on apo B mediate the cellular binding of hypertriglyceridemic VLDL1. However, the proportion of particles bound via apo B seems to increase as VLDL decreases in size toward LDL, and virtually all of LDL binding is mediated by apo B.
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46
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Tikkanen M, Schonfeld G. The recognition domain for the low density lipoprotein cellular receptor is expressed once on each lipoprotein particle. Biochem Biophys Res Commun 1985; 126:773-7. [PMID: 3977888 DOI: 10.1016/0006-291x(85)90251-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The stoichiometry of binding of monoclonal antibodies and Fab fragments to LDL was assessed. Increasing amounts of two [125I]-labelled antibodies which define epitopes at or near the LDL-receptor recognition domains of apoB were incubated with fixed amounts of LDL and antibody-LDL complexes were separated from free antibodies by heparin-MnCl2 precipitation. Saturation kinetics were obtained and data were analyzed according to Scatchard. One antibody or Fab fragment was bound per LDL particle. Homogeneity of binding was indicated by straight Scatchard lines and by the binding of virtually all LDL particles by an antibody affinity chromatographic column.
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47
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48
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Watt RM, Carhart RL, Gentile TC, Watt TS. Monoclonal antibodies to serum lipoproteins: their present and future use in biology and medicine. Pharmacol Ther 1985; 28:29-50. [PMID: 2414787 DOI: 10.1016/0163-7258(85)90081-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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49
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Nelson CA, Tasch MA, Tikkanen M, Dargar R, Schonfeld G. Evolution of low density lipoprotein structure probed with monoclonal antibodies. J Lipid Res 1984. [DOI: 10.1016/s0022-2275(20)37746-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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50
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Marcel YL, Weech PK, Milthorp P, Terce F, Vezina C, Milne RW. Monoclonal antibodies and the characterization of apolipoprotein structure and function. Prog Lipid Res 1984; 23:169-95. [PMID: 6086022 DOI: 10.1016/0163-7827(84)90010-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Y L Marcel
- Laboratory of Lipoprotein Metabolism, Clinical Research Institute of Montreal, Quebec, Canada
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