The kinetics and regulation of phosphofructokinase from Teladorsagia circumcincta

Molecular and biochemical characterisation of abomasal nematode parasites Teladorsagia circumcincta and Haemonchus contortus phosphofructokinases and their recognition by the immune host

“…There were also typical hyperbolic and sigmoidal curves relating enzyme velocity to substrate concentration at low and high ATP concentrations respectively. The recombinant TcPFK had very similar kinetic properties to the PFK activity in T. circumcincta homogenates (Walker et al, 2012), as has been the case for several other metabolic enzymes (Umair et al, 2011a(Umair et al, , 2011b(Umair et al, , 2013b, suggesting whole worm homogenates can be used to study the kinetic properties of many worm enzymes. Most parasite PFK have pH optima between 6.8 and 7 as is the case in A. suum PFK (Hofer et al, 1982a(Hofer et al, , 1982bRao et al, 1987Rao et al, , 1991aRao et al, , 1991b, homogenates of T. circumcincta (Walker et al, 2012), Dirofilaira immitis (Srinivasan et al, 1988), similar to the pH optima of pH 7 in the present study (Fig.…”

“…Mammalian PFK has three isoforms located in the liver, brain and muscle (Martinez-Costa et al, 2004), but only one was isolated in Ascaris suum (Starling et al, 1982). The enzyme properties and allosteric regulation of PFK-1 of A. suum (Hofer et al, 1982a(Hofer et al, , 1982bRao et al, 1987Rao et al, , 1991aRao et al, , 1991b and in homogenates of Teladorsagia circumcincta (Walker et al, 2012) are generally similar to those of mammalian PFK-1. Gene sequences are known for PFK-1 of A. suum (Kulkarni et al, 2005), Haemonchus contortus (Klein et al, 1991) Caenorhabditis elegans (Miersch and Doring, 2012) and Schistosoma mansoni (Ding et al, 1994), however, there appear to be no studies of the properties of recombinant nematode PFK-1.…”

Metabolic enzymes of helminth parasites: potential as drug targets

“…In the filarial parasite Setaria cervi, the enzyme may act as a secondary target for the anthelminthic suramin (Scheme 3) [101]. The enzyme has been characterised from a number of other species, including the nematodes Teladorsagia circumcincta [102] and A. suum [103,104], the trematode F. hepatica [105][106][107] and the cestode Hymenolepis diminuta [108]. To date, no compounds have been identified which mimic the worm clearing effectiveness of the trivalent antimonials but lack the side-effects.…”