scholarly journals Indirect Sandwich Enzyme-Linked Immunosorbent Assay (ELISA) for Plasma Apolipoprotein E

1996 ◽  
Vol 33 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Patrick Kee ◽  
Renze Bais ◽  
Stan K Sobecki ◽  
Susan Branford ◽  
Kerry-Anne Rye ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Low Density Lipoprotein ◽  
Sandwich Elisa ◽  
Density Lipoprotein ◽  
Gel Permeation Chromatography ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lipoprotein Subfractions ◽  
Apo E ◽  
Plasma Apolipoprotein

We have developed an indirect sandwich ELISA for measuring plasma apolipoprotein E (apo-E), using commercially available antibodies. A monoclonal anti-apo-E was used as the capture antibody and the captured apo-E detected with polyclonal anti-apo-E antiserum (goat). The detecting antibody was quantitated using horseradish peroxidase-conjugated rabbit immunoglobulin to goat immunoglobulins. There was no detectable cross-reactivity between the three antisera. Interference with the assay by apolipoprotein A-1, bilirubin and haemoglobin was not significant up to 1·7 g/L, 1250 μmol/L and 13·0 g/dL, respectively. The ELISA method showed high correlation with an established immunonephelometric method (ELISA apo-E=104 Immunonephelometric apo-E+16; r2 = 0·954, P < 0·0001, n = 39). The assay has a measuring range between 5 and 560 mg/L. The coefficient of duplicates was 20%, within-run coefficients of variation (CV) ranged from 3·7 to 6·0% and between-run CV from 6·1 to 15·1%. The reference range determined for 168 normotriglyceridaemic subjects was 20 to 130 mg/L. In an analysis of the lipoprotein subfractions isolated by ultracentrifugation as the fraction of density less than 1·25 g/mL and separated by gel permeation chromatography, apo-E was found to be associated with very low-density lipoprotein and large high-density lipoprotein.

scholarly journals VLDL (Very-Low-Density Lipoprotein)-Apo E (Apolipoprotein E) May Influence Lp(a) (Lipoprotein [a]) Synthesis or Assembly

2020 ◽  
Vol 40 (3) ◽  
pp. 819-829 ◽  
Author(s):  
Mikaël Croyal ◽  
Valentin Blanchard ◽  
Khadija Ouguerram ◽  
Maud Chétiveaux ◽  
Léa Cabioch ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein A ◽  
Apo E

scholarly journals Influence of the polymorphism of apolipoprotein E in cerebral vascular disease

2003 ◽  
Vol 61 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Dorotéia R.S. Souza ◽  
Bernadete F. Campos ◽  
Érika F. de Arruda ◽  
Lucy J. Yamamoto ◽  
Daniel M. Trindade ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Lipid Profile ◽  
Clinical Symptoms ◽  
Statistical Significance ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Control Group ◽  
Reduced Frequency ◽  
Apo E ◽  
The Relationship

The genetic heterogeneity of apolipoprotein E (apo E) has been associated with lipid profile and atherothrombotic stroke, however this association remains inconclusive. OBJECTIVE: To evaluate the relationship between the isoforms of apo E and atherothrombotic stroke, by ascertaining the frequency of its alleles and genotypes associated with the lipid profile in patients with stroke. METHOD: A total of 207 individuals were divided into two groups, consisting of 107 patients with stroke and 100 individuals without clinical symptoms of the disease. Blood samples were taken from patients and controls for molecular investigation of the apo E (epsilon2, epsilon3 and epsilon4 alleles) for the analysis of the lipid profile. RESULTS: The epsilon3 allele was the most common and its prevalence was significantly higher in patients (0.93) compared to the controls (0.86; p=0.024). The epsilon2 allele was rarely seen specifically in patients (0.02 versus 0.05 in controls, p=0.191). The epsilon4 allele was not associated with stroke showing a reduced frequency in patients (0.05) when compared to controls (0.09; p=0.011). Although higher average levels of lipid profile were found in patients when compared to controls, with statistical significance for the values of total cholesterol (TC) (203.6mg/dL±57.98 and 181.9mg/dL±68.47 respectively; p=0.003) and low-density lipoprotein cholesterol (LDLc) (131.4mg/dL±52.60 and 116mg/dL±56.38, respectively; p=0.014), these were independent of the presence of the epsilon4 allele. In control group the higher TC and LDLc values occurred in the absence of the epsilon4 allele, confirming the conflicting effect of the alleles of apo E on the plasmatic lipids and atherothrombotic stroke. CONCLUSION: The isoforms of apo E cannot be regarded as an isolated risk factor for stroke and do not show association with lipid profile in this study.

scholarly journals The isolation and characterization of high-density-lipoprotein subfractions containing apolipoprotein E from human plasma

1992 ◽  
Vol 284 (2) ◽  
pp. 477-481 ◽  
Author(s):  
H M Wilson ◽  
B A Griffin ◽  
C Watt ◽  
E R Skinner
Keyword(s):  
High Density Lipoprotein ◽  
Apolipoprotein E ◽  
Density Lipoprotein ◽  
Major Fatty Acid ◽  
High Density ◽  
Lipoprotein Subfractions ◽  
Binding Effect ◽  
Isolation And Characterization ◽  
Apo E ◽  
Significant Difference

1. Plasma high-density lipoprotein (HDL) was separated by heparin-Sepharose affinity chromatography into a non-bound, apolipoprotein E-poor, and a bound, apolipoprotein E-rich, fraction through the binding effect of Mn2+ in the column buffer. 2. The application of a series of elution buffers in which the concentration of Mn2+ was progressively replaced by Mg2+ resulted in the separation of the bound HDL into five subfractions. 3. Each subfraction migrated a different distance on gradient-gel electrophoresis. Three of the subfractions had RF (relative migration compared with BSA) values within the range of HDL2b. One subfraction contained largely HDL2a, with some material in the regions of HDL2b and HDL3a, and one subfraction spanned the RF regions of HDL2a, HDL3a and HDL3b. 4. The number of molecules, per HDL particle, of cholesteryl ester, non-esterified cholesterol and phospholipid increased with particle size, whereas triacylglycerol passed through a maximum and the number of amino acid residues remained approximately the same. 5. Apolipoprotein (apo) A-I was the major apoprotein in all five subfractions, but the latter differed appreciably in their contents of apo A-II and apo E. 6. The major fatty acid component of each subfraction was linoleic acid, with moderate amounts of C16:0 and C18:1 fatty acids and a smaller content of C18:0, C20:4,n-6 and C22:6,n-3, with no significant difference in composition between the subfractions. 7. This paper provides the first description of a method for the isolation of three subfractions of HDL2b together with other subfractions in quantities that are sufficient for further analytical or metabolic studies.

Enzyme-linked immunoabsorbant assay of apolipoprotein AII in plasma, with use of a monoclonal antibody.

1986 ◽  
Vol 32 (6) ◽  
pp. 967-971 ◽  
Author(s):  
E A Stein ◽  
L DiPersio ◽  
A J Pesce ◽  
M Kashyap ◽  
J T Kao ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Solid Phase ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cross Reactivity ◽  
Lipoprotein Subfractions ◽  
Parallel Displacement ◽  
Standard Curve ◽  
Human Apolipoprotein ◽  
Plasma High Density

Abstract We produced a monoclonal antibody (C2-22) to human apolipoprotein (Apo) AII and describe its use in an enzyme-linked immunoabsorbant assay (ELISA) for Apo AII in human plasma and lipoprotein subfractions. No cross reactivity of the antibody with Apo CI, CII, CIII, E, or ablumin was detected. Apo AI and low- and very-low-density lipoprotein cross reacted by 0.25%, less than 0.2%, and less than 0.3%, respectively. Whole plasma high-density lipoprotein (HDL) and HDL subfractions (HDL2 and HDL3) produced parallel displacement curves. This quantitative ELISA is based on competition between solid-phase-bound Apo AII and free Apo AII. Bound C2-22 is detected by alkaline-phosphatase-labeled second antibody. The standard curve for the assay is linear for plasma diluted 500-fold originally containing 140 to 1140 mg of Apo AII per liter. Delipidation of plasma samples exposed no additional antigenic sites. Within- and between-run CVs were respectively 8.4% and 8.7% at 327 mg/L of Apo AII, and 6.8% and 7.4% at 587 mg/L. Results correlated well with those by a polyvalent-antisera-based RIA procedure: r = 0.916, p less than 0.01, RIA = 0.896 ELISA -19.1 mg/L.

Very-low-density lipoprotein binding to the apolipoprotein E receptor 2 is enhanced by lipoprotein lipase, and does not require apolipoprotein E

2000 ◽  
Vol 347 (2) ◽  
pp. 357-361 ◽  
Author(s):  
Paul J. TACKEN ◽  
Femke DE BEER ◽  
Leonie C. VAN VARK ◽  
Louis M. HAVEKES ◽  
Marten H. HOFKER ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Lipoprotein Lipase ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Vldl Receptor ◽  
Apo E ◽  
Lipoprotein Binding

The apolipoprotein (apo)E receptor 2 (apoER2) is a recently cloned member of the low-density lipoprotein (LDL) receptor (LDLR) family, showing a high homology with both the LDLR and the very-low-density lipoprotein (VLDL) receptor (VLDLR). In the present study, the binding characteristics of the apoER2 with respect to apoE and lipoprotein lipase (LPL) were investigated. VLDL was isolated from both apoE-deficient mice and mice expressing the human APOE2 (Arg158 → Cys) and APOE3-Leiden isoforms on an Apoe-/-,Ldlr-/- double knock-out background. apoE-rich rabbit β-VLDL was used as a positive control for binding. Binding experiments performed with Chinese hamster ovary cells expressing the human apoER2 showed that the receptor was able to bind VLDL containing either of the apoE isoforms, as well as the apoE-deficient VLDL. Hence, in contrast with the VLDLR, the apoER2 is not strictly dependent on apoE for VLDL binding. Since LPL has been shown to enhance the binding of lipoproteins to several members of the LDLR family, including the LDLR-related protein, VLDL receptor, gp330 and the LDLR itself, VLDL binding experiments were performed in the presence of LPL. Addition of LPL resulted in a significant increase in apoER2 binding for all VLDL fractions used in this study. In conclusion, lipoprotein binding of VLDL to the apoER2 is enhanced in the presence of LPL, and is not restricted to apoE-containing lipoproteins.

scholarly journals Effect of apolipoprotein E phenotype on diet-induced lowering of plasma low density lipoprotein cholesterol.

1994 ◽  
Vol 35 (11) ◽  
pp. 1965-1975
Author(s):  
J Lopez-Miranda ◽  
J.M. Ordovas ◽  
P Mata ◽  
A.H Lichtenstein ◽  
B Clevidence ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol
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