sodium-dodecyl-sulfate and Hyperlipidemias

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.

Topics: Apolipoprotein B-100; Apolipoprotein B-48; Apolipoproteins B; Chromogenic Compounds; Electrophoresis, Polyacrylamide Gel; Humans; Hyperlipidemias; Kinetics; Lipoproteins; Rosaniline Dyes; Sodium Dodecyl Sulfate

The atherogenic low density lipoproteins were evaluated using two turbidimetric methods: one based on the precipitation of LDL and VLDL by heparin-CaCl2 and the other on the precipitation of the VLDL by sodium dodecyl sulfate. In search of hyperlipoproteinemia, both tests were applied to a population of blood donors aged from 18 to 60 years. when both tests were negative, hyperlipoproteinemia can be excluded without quantitative evaluation of cholesterol and triglycerides levels. If the heparin-CaCl2 test is high and the SDS normal it can be concluded that it is a case of type IIa hyperlipidemia. When both test are high, further investigations are required. In the present study, corresponding to the screening of the sera from 2656 blood donors (including 1280 males and 1376 females), the high level of atherogenic lipoproteins is most frequently observed in the males (10 per cent for men and 2,5 per cent for women). This frequency increases with age.

Topics: Adolescent; Adult; Age Factors; Blood Donors; Calcium Chloride; Chemical Precipitation; Female; Heparin; Humans; Hyperlipidemias; Lipoproteins, LDL; Lipoproteins, VLDL; Male; Middle Aged; Nephelometry and Turbidimetry; Sex Factors; Sodium Dodecyl Sulfate

Lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) are lipolytic activities found in postheparin plasma. A simple and precise method for the direct determination of LPL in postheparin plasma is described. Pre-incubations of this plasma (45--60 min at 26 degrees C) with sodium dodecyl sulfate (35--50 mM) in 0.2 M Tris-HCl buffer, pH 8.2, results in the inactivation of H-TGL, while leaving LPL fully active. Direct determination of H-TGL is done in a separate aliquot of the same postheparin plasma sample using previously reported assay conditons that do not measure LPL. The sodium dodecyl sulfate-resistant lipolytic activity has the characteristics of LPL as judged by a) its activation by serum and by apolipoprotein C-II; b) its inactivation (over 90%) by 0.75 M NaCl; and c) its inactivation by a specific antiserum. No sodium dodecyl sulfate-resistant activity was found in postheparin plasma from a patient with LPL deficiency (primary type I hyperlipoproteinemia). An excellent correlation of values was obtained (r = 0.99) for 30 samples assayed after sodium dodecyl sulfate treatment and after immuno-inactivation of H-TGL. The intra-assay coefficient of variation was +/- 11% and 4% before and after normalization of values, respectively.

Topics: Female; Heparin; Humans; Hyperlipidemias; Kinetics; Lipase; Lipoprotein Lipase; Liver; Male; Sodium Dodecyl Sulfate; Triglycerides

Topics: Humans; Hyperlipidemias; Lipoproteins, LDL; Lipoproteins, VLDL; Nephelometry and Turbidimetry; Sodium Dodecyl Sulfate

Topics: Calcium Chloride; Chemical Precipitation; Cholesterol; Dextrans; Humans; Hyperlipidemias; Lipoproteins; Lipoproteins, HDL; Lipoproteins, LDL; Lipoproteins, VLDL; Methods; Sodium Dodecyl Sulfate; Sulfates; Triglycerides; Ultracentrifugation