The kinetics and regulation of phosphofructokinase from Teladorsagia circumcincta

Walker, L.R., Simcock, D.C., Pedley, K.C., Simpson, H.V., and Brown, S. (2012) The kinetics and regulation of phosphofructokinase from Teladorsagia circumcincta. Experimental Parasitology, 130 (4). pp. 348-353.

[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: http://dx.doi.org/10.1016/j.exppara.2012...
3


Abstract

Phosphofructokinase (PFK-1) activity was examined in L3 and adult Teladorsagia circumcincta, both of which exhibit oxygen consumption. Although activities were higher in the adult stage, the kinetic properties of the enzyme were similar in both life cycle stages. T. circumcincta PFK-1 was subject to allosteric inhibition by high ATP concentration, which increased both the Hill coefficient (from 1.4 ± 0.2 to 1.7 ± 0.2 in L3s and 2.0 ± 0.3 to 2.4 ± 0.4 in adults) and the K½ for fructose 6 phosphate (from 0.35 ± 0.02 to 0.75 ± 0.05 mM in L3s and 0.40 ± 0.03 to 0.65 ± 0.05 mM in adults). The inhibitory effects of high ATP concentration could be reversed by fructose 2,6 bisphosphate and AMP, but glucose 1,6 bisphosphate had no effect on activity. Similarly, phosphoenolpyruvate had no effect on activity, while citrate, isocitrate and malate exerted mild inhibitory effects, but only at concentrations exceeding 2 mM. The observed kinetic properties for T. circumcincta PFK-1 were very similar to those reported for purified Ascaris suum PFK-1, though slight differences in sensitivity to ATP concentration suggests there may be subtle variations at the active site. These results are consistent with the conservation of properties of PFK-1 amongst nematode species, despite between species variation in the ability to utilise oxygen.

Item ID: 35753
Item Type: Article (Research - C1)
ISSN: 1090-2449
Keywords: Teladorsagia circumcincta, nematode, phosphofructokinase
Funders: Beef and Lamb New Zealand, Agricultural and Marketing Research and Development Trust (AGMARDT)
Date Deposited: 15 Oct 2014 16:48
FoR Codes: 06 BIOLOGICAL SCIENCES > 0601 Biochemistry and Cell Biology > 060107 Enzymes @ 50%
07 AGRICULTURAL AND VETERINARY SCIENCES > 0707 Veterinary Sciences > 070708 Veterinary Parasitology @ 50%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 50%
97 EXPANDING KNOWLEDGE > 970107 Expanding Knowledge in the Agricultural and Veterinary Sciences @ 50%
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page