A sedimentation procedure for the detection of binding of concanavalin A and heparin to lipoproteins

Studies of the interactions between dissimilar macromolecules are of considerable importance but pose special technical problems in comparison with small-ligand binding studies, since dialysis procedures are frequently inapplicable. This communication describes a sedimentation velocity procedure for detecting the binding of proteins and polysaccharides to lipoproteins and for examining perturbations resulting from the introduction of selected ligands. It makes use of the significant difference in density between the lipoprotein and the interacting macromolecule. The procedure is illustrated by studies of the binding of serum low density lipoprotein (LDL) to concanavalin A (con A) and heparin.