Résumé
Cell free extracts from M. tuberculosis H37 Rv, M. smegmatis armadillo derived M. leprae and normal armadillo liver homogenates were assayed for the presence of isocitrate lyase and malate synthase activity. It was observed that significant amount of isocitrate lyase and malate synthase activity was present in M. tuberculosis H37 Rv, M. smegmatis and armadillo derived M. leprae. No such activity was demonstrable in cell free extracts of normal armadillo liver. It is concluded that M. leprae like other mycobacteria has the capability to metabolise via glyoxylate bypass of TCA cycle. These findings may be relevant for understanding the energy metabolism of M. leprae under stress conditions and possibly the 'persister' stage.
Sujets)
Animaux , Tatous , Isocitrate lyase/métabolisme , Foie/enzymologie , Malate synthase/métabolisme , Mycobacterium/enzymologie , Mycobacterium leprae/enzymologie , Mycobacterium tuberculosis/enzymologie , Oxo-acid-lyases/métabolismeRésumé
O ficomiceto dimórfico Mucor rouxii foi cultivado em meio que continha glucose a 2% (YPG), tendo-se verificado um crescimento bifásico característico. A isocitrato liase, enzima do ciclo do glioxilato, apareceu sob estas condiçöes somente após a glucose do meio ter sido totalmente esgotada. Altos níveis de atividade da isocitrato liase foram encontrados durante o metabolismo gluconeogenético. Isso mostra a participaçäo do ciclo do glioxilato como fonte de succinato e de oxalacetato para as vias biossintéticas do fungo. Em meio complexo sem glucose (YP), estritamente gluconeogenético, foram encontradas altas atividades de isocitrato liase