title: Protein components in the very low density lipoproteins of hen's egg yolks. Identification of highly aggregating (gelling) and less aggregating (non-gelling) proteins.
abstract: Apoproteins of hen's egg yolk very low density lipoprotein has been separated by Sephadex G-200 gel filtration in 0.5% sodium dodecyl sulfate into three categories of proteins termed apoprotein A, apoprotein B and apoprotein C. Apoprotein A fraction consists of several aggregated proteins (linked possibly by -S-S- bridges) as shown by acrylamide gel electrophoresis in the presence of 2-mercaptoethanol. Apoprotein B contains two major protein components, B1 and B2, with molecular weights of 78 000 and 64 000, respectively, and two minor proteins components. Apoprotein C was obtained in a pure form as a low molecular weight, -S-S- linked dimer protein and accounted for about 30% of the total protein. In the monomeric form, apoprotein C has a molecular weight of 9400. Apoprotein A and apoprotein B have similar amino acid composition, except in isoleucine content which is over two times in apoprotein B as compared to apoprotein A. Apoprotein C lacks histidine and is richer in arginine than apoproteins A or B. Apoprotein C has lysine as N-terminal, while apoproteins A and B have predominantly arginine as the N-terminal amino acid. All the three fractions contain carbohydrate residues, apoprotein B being the richest in carbohydrate content. Cold-stored apoproteins A forms a clear gel when dispersed in 0.5% sodium dodecyl sulfate at concentration of above 2 mg/ml, while apoprotein B forms a gel only above 10 mg/ml. Apoprotein C, even at 35 mg/ml, forms a clear solution with no tendency to gel.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001053:Apolipoproteins / Q000302:isolation & purification; D002645:Chickens; D004530:Egg Yolk; D005260:Female; D006595:Hexosamines / Q000032:analysis; D006601:Hexoses / Q000032:analysis; D008079:Lipoproteins, VLDL / Q000302:isolation & purification; D046911:Macromolecular Substances; D008970:Molecular Weight
chemical_list: D000596:Amino Acids; D001053:Apolipoproteins; D006595:Hexosamines; D006601:Hexoses; D008079:Lipoproteins, VLDL; D046911:Macromolecular Substances