Phosphofructokinase activities within the order Spirochaetales and the characterisation of the pyrophosphate-dependent phosphofructokinase from Spirochaeta thermophila

The subtype of phosphofructokinase activity, either ATP-, ADP- or pyrophosp hate-dependent, present in members of three genera from the Spirochaetales was investigated. The individual species/strains examined included Spirocha eta alkalica, S. asiatica, S. halophila, S. isovalerica, S. litoralis, S. z uelzerae, S. thermophila, two thermophilic spirochetes, Treponema bryantii T. denticola, T. pectinovorum, Leptospira biflexa and L. interrogans. All o f the Spirochaeta strains, regardless of their phenotype, possessed primari ly a pyrophosphate-dependent phosphofructokinase. In contrast, T. bryantii, T. denticola and L. biflexa had predominantly an ATP-dependent activity, w hereas no activity was detected in T. pectinovorum or L. interrogans. The r esults suggest that pyrophosphate-dependent phosphofructokinase activity ma y be a reliable phenotypic marker for the genus Spirochaeta and that there are potentially interesting differences in how the catabolism of saccharide s is controlled among members of genera within the Spirochaetales. The pyro phosphate-dependent phosphofructokinase from S. thermophila strain RI 19.B1 was purified (303-fold) to homogeneity and biochemically characterised. Th e S. thermophila enzyme displayed hyperbolic kinetics with respect to both the forward and reverse cosubstrates and was not significantly affected by traditional activators or inhibitors of phosphofructokinase. The biochemica l characterisation represents the first spirochete phosphofructokinase to b e described.