Methione Metabolism in Filarial Worms

 ABSTRACT

Adult filariae apparently lack the vitamin BI2-dependent and -independent methyltransferases for the de novo synthesis of metonline and seem to meet their requirement of this amino acid from an exogenous source and the activity of S - a d e nos y lm et hi o ni ne ( Ad o Me t) : homocysteine S-methyltransferase. The properties of filarial AdoMet: homocysteine methyltransferase was similar to the analogous microbial enzyme. However, adult filariae possess the enzymatic capability to metabolize methionine to cyst(e)ine. When incubated in the presence of L - f C H ^ - ^ C j m e t h i o n i n e to induce them to synthesise AdoMet, adult Dirofilaria immitis incorporated the radiolabel into phospholipid and protein fractions. The significance of filarial methionine metabolism especially with regard to its suitability as a potential target for antifilarial chemotherapy is discussed.