Biochemical characterization of a low-affinity arginine permease from the parasite Trypanosoma cruzi.
Trypanosoma cruzi, the etiological agent of Chagas disease, uses arginine for several metabolic processes, including energy reserves management. In the present work, a novel low-affinity arginine transport system has been studied. Maximum velocity (97 pmol min(-1) per 10(7) cells), and an estimate for the apparent Km value (350 microM) of this arginine transporter, were 6-fold and 80-fold higher respectively, when compared with the previously described high-affinity arginine transport system. This transport activity seems to be H+ -mediated, presents a broad specificity by other amino acids such as methionine, and is regulated along the parasite growth curve and life cycle.
Canepa
Gaspar E
GE
Laboratorio de Biología Molecular de Trypanosoma cruzi, Instituto de Investigaciones Médicas Alfredo Lanari, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Argentina.
Silber
Ariel M
AM
Bouvier
León A
LA
Pereira
Claudio A
CA
D026905:Amino Acid Transport Systems / Q000378:metabolism*; D026923:Amino Acid Transport Systems, Basic; D000818:Animals; D001120:Arginine / Q000378:metabolism*; D004789:Enzyme Activation; D007700:Kinetics; D013379:Substrate Specificity; D013696:Temperature; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000254:growth & development
D026905:Amino Acid Transport Systems; D026923:Amino Acid Transport Systems, Basic; C043909:arginine permease; D001120:Arginine