Please use this identifier to cite or link to this item:
|Title:||Functional analysis, overexpression, and kinetic characterization of pyruvate kinase from Plasmodium falciparum|
|Citation:||Chan, M., Sim, T.-S. (2004). Functional analysis, overexpression, and kinetic characterization of pyruvate kinase from Plasmodium falciparum. Biochemical and Biophysical Research Communications 326 (1) : 188-196. ScholarBank@NUS Repository. https://doi.org/10.1016/j.bbrc.2004.11.018|
|Abstract:||The important role of pyruvate kinase during malarial infection has prompted the cloning of a cDNA encoding Plasmodium falciparum pyruvate kinase (pfPyrK), using mRNA from intraerythrocytic-stage malaria parasites. The full-length cDNA encodes a protein with a computed molecular weight of 55.6 kDa and an isoelectric point of 7.5. The purified recombinant pfPyrK is enzymatically active and exists as a homotetramer in its active form. The enzyme exhibits hyperbolic kinetics with respect to phosphoenolpyruvate and ADP, with Km of 0.19 and 0.12 mM, respectively. pfPyrK is not affected by fructose-1,6-bisphosphate, a general activating factor of pyruvate kinase for most species. Glucose-6-phosphate, an activator of the Toxoplasma gondii enzyme, does not affect pfPyrK activity. Similar to rabbit pyruvate kinase, pfPyrK is susceptible to inactivation by 1 mM pyridoxal-5′-phosphate, but to a lesser extent. A screen for inhibitors to pfPyrK revealed that it is markedly inhibited by ATP and citrate. Detailed kinetic analysis revealed a transition from hyperbolic to sigmoidal kinetics for PEP in the presence of citrate, as well as competitive inhibitory behavior for ATP with respect to PEP. Citrate exhibits non-competitive inhibition with respect to ADP with a Ki of 0.8 mM. In conclusion, P. falciparum expresses an active pyruvate kinase during the intraerythrocytic-stage of its developmental cycle that may play important metabolic roles during infection. © 2004 Elsevier Inc. All rights reserved.|
|Source Title:||Biochemical and Biophysical Research Communications|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Nov 13, 2018
WEB OF SCIENCETM
checked on Nov 5, 2018
checked on Oct 20, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.