Adsorption of serum lipoproteins from rainbow trout to dextran sulfate cellulose

The characteristics of serum lipoproteins from rainbow trout were investigated using dextran sulfate cellulose (DSC) gel. The binding profiles of very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL), and vitellogenin (VTG) to DSC gel were consistent with a simple Langmuir's adsorption isotherm. The dissociation constants of VTG and VLDL were lower than those of LDL and HDL, suggesting high affinities of VTG and VLDL for DSC gel. VTG and VLDL were found to have specific capacities for binding to DSC gel from the values of maximum binding level. When applied to a DSC column, both unbound and bound fractions were present in VLDL and LDL. Apolipoprotein components differed in unbound and bound fractions, and apolipoprotein B-like protein of molecular weight 260,000 (Mr 260 K) in both VLDL and LDL seemed to have a high affinity for DSC gel. Taking into account that VTG which possessed apolipoprotein with Mr 170 K as a main component had the highest binding capacity to DSC gel, a structural similarity was strongly suggested between apolipoprotein B-like protein in VLDL and LDL and apolipoprotein in VTG.