High density lipoproteins from bovine plasma and follicular fluid do not possess a high affinity for glycosaminoglycans.

Abstract

Possible interactions between glycosaminoglycans and high density lipoproteins (HDL) in plasma and follicular fluid were examined. Total lipoproteins (d less than 1.21 g/ml) were obtained from plasma of five Holstein cows by ultracentrifugation and fractionated by gel filtration. Every other fraction from the HDL peak or fractions corresponding to the base and ascending portion of the HDL peak were composited and applied to a heparin-Sepharose affinity chromatography column. Elution profiles from both composites showed a peak that did not bind to the column that contained HDL devoid of apolipoprotein-E as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining and immunoblot analysis. Elution of lipoproteins from the ascending portion of the HDL peak resulted in a second minor peak eluting at 0.35 M NaCl, which was low density lipoprotein (LDL) contamination. Lipoproteins (d less than 1.21 g/ml) isolated from follicular fluid obtained from small, medium or large follicles also were subjected to heparin-Sepharose affinity chromatography. Two peaks were observed, one corresponding to the lipoprotein that did not bind to the column, the other eluted at 0.5 M NaCl and accounted for less than 2% of the protein applied. The second peak did not contain apolipoprotein-E or LDL. Bovine follicular fluid glycosaminoglycans (GAG) were isolated and subjected to HDL-Sepharose affinity chromatography. Less than 2% of the total GAG bound to the HDL column. Therefore, HDL in bovine specimens did not interact appreciably with heparin or GAG isolated from follicular fluid.