Amino acid transport and incorporation in red blood cells of normal and Plasmodium knowlesi-infected rhesus monkeys

Abstract

Amino acid transport and incorporation in red blood cells of normal and Plasmodium knowlesi-infected rhesus monkeys. Experimental Parasitology 27, 143–149. Distribution ratios and incorporation into protein in vitro of 14C-labeled leucine, Isoleucine, cystine, methionine, and histidine were measured in red blood cells from normal and Plasmodium knowlesi-infected rhesus monkeys. Distribution ratios of Isoleucine and methionine were greater in infected blood cells than in uninfected cells, the ratios of cystine appeared somewhat increased, and those of leucine and histidine were unchanged. Incorporation of 14C-amino acids into protein was generally much greater in parasitized blood. 14C-Isoleucine incorporation was 150 times that in uninfected blood. The other amino acids had smaller ratios: methionine, 30; leucine, 16; histidine, 16; cystine, 4. The P. knowlesi parasite is capable of accumulation of specific amino acids from outside the red blood cell. The incorporation of 14C-amino acids into protein by uninfected blood was negligible, in general, compared to the incorporation by infected cells.