NH2-terminal amino acids of the serum lipoproteins of normal and hypercholesterolemic rabbits*

Abstract

Aspartic acid is the major and glutamic acid and serine are minor NH2-terminal amino acids of the lipoproteins of rabbit serum. No NH2-terminal amino acids other than these are found after prolonged cholesterol feeding. The hyperlipoproteinemia accompanying the feeding is not characterized by any significant changes in the NH2-terminal amino acid composition of the density (d) < 1.007, 1.007 to 1.019, or 1.065 to 1.20 lipoproteins. However, in the d = 1.019 to 1.065 lipoproteins, the percentages of NH2-terminal glutamic acid and aspartic acid seem to increase and decrease, respectively, during feeding.