Isolation and Alignment of the Tryptic Peptides of Alanine Apolipoprotein, an Apolipoprotein from Human Plasma Very Low Density Lipoproteins

Alanine apolipoprotein (apoLP-Ala) was prepared from the very low density lipoproteins of patients with familial type V hyperlipoproteinemia. Tryptic peptides of the succinylated and unmodified protein were isolated and characterized. Determination of the amino acid composition and terminal residues of each of the peptides permitted the alignment of all but two small basic peptides. Carbohydrate was demonstrated to be bound to the COOH-terminal tryptic peptide of apoLP-Ala, probably by an O-glycosidic bond to a threonine residue.