Abstrakt: |
Human high density lipoprotein (HDL) and its subfractions (HDL2 and HDL3) were separated by ultracentrifugation and the molar ratio of the two major polypeptide chains apo-Gln-I and apo-Gln-II was determined by fluorescence tagging of sodium dodecyl sulfate-denatured proteins combined with polyacrylamide disc gel electrophoresis. Using purified apo-Gln-I and apo-Gln-II standards, it was found that holo HDL, holo HDL2, and holo HDL3 from all plasma samples contained a molar ratio of apo-Gln-I to the disulfide-bound dimer of apo-Gln-II of 2:1, that is a 1:1 ratio in terms of each species of polypeptide chain. The method described is useful for making repeated and rapid measurements on microgram quantities of intact lipoproteins. |