Isolation and Fractionation of the Protein Moiety of Egg Yolk Low Density Lipoprotein

The protein moiety of egg yolk LDL was a mixture of glycoproteins which separated into several bands by SDS polyacrylamide gel electrophoresis. The main component was a large protein of 130,000 molecular weight, and represented over 70% of the total proteins. Among other components, the smallest protein made up about 20% of total proteins and had a molecular weight of 15,000. Remaining components included at least four proteins with molecular weights in the range of 60,000–95,000. The main protein and the smallest protein could be separated from other components by gel filtration on Sepharose 4B. Although their amino acid composition was almost the same, their carbohydrate content was different. Other components besides these two proteins were assumed to be derived from the main protein during the preparation of delipidation.