Physicochemical properties of apolipoprotein(a) and lipoprotein(a-) derived from the dissociation of human plasma lipoprotein (a).

摘要: Chemical reduction of human plasma lipoprotein(a) (Lp(a)) yielded two water-soluble products which were separated by rate zonal ultracentrifugation. Apolipoprotein(a) (apo(a)) was completely recovered from the bottom gradient, whereas lipoprotein(a-) (Lp(a-)), contained all lipids and apo-B100 Lp(a), floated. By techniques circular dichroism viscometry Lp(a-) identical to low density lipoprotein (LDL). slightly larger in mass than autologous LDL proportionally more triglyceride. The difference between Lp(a) accounted for loss 2 molecules apo(a) particle. molecular weight reduced carboxymethylated 281,000 as determined sedimentation equilibrium 6 M guanidine HCl. structure mostly random (71%) with remainder representing 8% alpha-helix 21% beta-sheet; its intrinsic viscosity, 28.3 cm3/g, consistent an extended flexible coil. amino acid composition characterized unusually high content proline (11.4 mol %) well tryptophan, tyrosine, arginine, threonine, a amount lysine, phenylalanine, isoleucine. Apo(a) 28.1% carbohydrate represented mannose, galactose, galactosamine, glucosamine, sialic approximate molar ratio 3:7:5:4:7, respectively. Overall, appears be rigid spherical LDL-like core particle which, consequence association glycoprotein such apo(a), favors entrapment significant amounts hydrodynamically associated solvent. Furthermore, remnant generated removal similar but not LDL.