Direct phenotyping of human apolipoprotein E in plasma: application to population frequency distribution in Paris (France).
Apolipoprotein E (Apo E) is a component of VLDL and HDL and plays a significant role in the regulation of cholesterol concentration. An improvement in isoelectric focusing for Apo E phenotyping is presented: the plasma Apo E was dissociated from lipoproteins by the use of Tween 20; the optimal concentration of type V neuraminidase was determined (1 U/ml); up to 48 samples were analyzed per plate and revealed by immunoblotting. Using this method, we have determined Apo E phenotypes and estimated their association with total cholesterol and Apo B levels in 498 healthy blood donors in Paris (France). The relative frequencies of Apo E alleles epsilon 2, epsilon 3 and epsilon 4 in this population were 0.079, 0.801 and 0.120, respectively. The association between Apo E phenotypes and concentration of Apo B-containing lipoproteins was confirmed (Apo B (g/l): E4/E3 subjects, 1.10 +/- 0.29; E3/E2 subjects, 0.93 +/- 0.22; both significantly different from E3/E3 subjects, 0.99 +/- 0.28). Total cholesterol (mmol/l): E4/E3 subjects, 5.43 +/- 1.15; E3/E2 subjects, 4.79 +/- 0.83; both significantly different from E3/E3 subjects, 5.03 +/- 1.11.
Bailleul
S
S
Service de Biochimie, Hôpital Tenon, Paris, France.
Couderc
R
R
Landais
V
V
Lefèvre
G
G
Raichvarg
D
D
Etienne
J
J
D000328:Adult; D000483:Alleles; D001055:Apolipoproteins B / Q000097:blood; D001057:Apolipoproteins E / Q000097:blood / Q000235:genetics*; D001782:Blood Donors; D002784:Cholesterol / Q000097:blood; D005260:Female; D005787:Gene Frequency; D006801:Humans; D015151:Immunoblotting; D016130:Immunophenotyping; D007525:Isoelectric Focusing; D008297:Male; D008875:Middle Aged; D009439:Neuraminidase; D010297:Paris; D010641:Phenotype; D011110:Polymorphism, Genetic
D001055:Apolipoproteins B; D001057:Apolipoproteins E; D002784:Cholesterol; D009439:Neuraminidase