title: Purine phosphoribosyltransferases of Leishmania mexicana mexicana and other flagellate protozoa.
abstract: Amastigotes and cultured promastigotes of Leishmania mexicana mexicana and L. m. amazonensis, cultured promastigotes of L. donovani and L. tarentolae, and the culture forms of Crithidia fasciculata, Herpetomonas muscarum muscarum and H. m. ingenoplastis all possessed four phosphoribosyltransferase (PRTase) activities: adenine PRTase, hypoxanthine PRTase, guanine PRTase and xanthine PRTase. The enzymes of L. m. mexicana required divalent cations for activity; Mn2+ or Co2+ produced maximal activity in most cases. Hypoxanthine PRTase, guanine PRTase and xanthine PRTase from all organisms were sedimentable in part, suggesting that they may occur within glycosomes. The enzymes of L. m. mexicana cultured promastigotes were inhibited by a range of purine analogues.
mesh_terms: D000228:Adenine Phosphoribosyltransferase / Q000378:metabolism; D000818:Animals; D002413:Cations, Divalent; D056890:Eukaryota / Q000201:enzymology*; D007041:Hypoxanthine Phosphoribosyltransferase / Q000378:metabolism; D007700:Kinetics; D007894:Leishmania mexicana / Q000201:enzymology*; D010430:Pentosyltransferases / Q000378:metabolism*; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D002413:Cations, Divalent; D010430:Pentosyltransferases; D011683:Purine-Nucleoside Phosphorylase; C024827:xanthine phosphoribosyltransferase; D000228:Adenine Phosphoribosyltransferase; D007041:Hypoxanthine Phosphoribosyltransferase