Plasmodium knowlesi: in vitro Biosynthesis of Methionine.

摘要

Methionine biosynthesis was studied in Rhesus monkey erythrocytes infected with plasmodium knowlesi malaria which were cultured in vitro with L-serine-3-14-carbon, methyl-14-carbon-tetrahydrofolic acid and L-Homocysteine-35-sulfur. Radioactivity from serine was detected in methionine and thymidylic acid by thin layer chromatography. Results with methyltetrahydrofolic acid were inconclusive. Radioactivity from homocysteine also appeared in methionine but the level of homocysteine required for maximal activity was ten-fold that of serine. The results indicate that the serine: 5,10-methylenetetrahydrofolic acid: 5-methyltetrahydrofolic acid: methionine pathway is present in the plasmodium knowlesi malarial parasite. (Author)