Zininga, T.Hoppe, H.C.Prinsloo.E.Dirr, H.W.Shonhai, A.Achilonu, I.2016-09-162016-09-162015-06-17Zininga, T. et al. 2015. Overexpression, purification and characterisation of the Plasmodium falciparum Hsp70-z (PfHsp70-z) protein. PLOS ONE 10(6):e01294451932-6203http://hdl.handle.net/10539/21038Six Hsp70-like genes are represented on the genome of Plasmodium falciparum. Of these two occur i0n the cytosol: P. falciparum Hsp70-z (PfHsp70-z) and PfHsp70-1. PfHsp70-1 is a well characterised canonical Hsp70 that facilitates protein quality control and is crucial for the development of malaria parasites. There is very little known about PfHsp70-z. However, PfHsp70-z is known to be essential and is implicated in suppressing aggregation of asparagine-rich proteins of P. falciparum. In addition, its expression at the clinical stage of malaria correlates with disease prognosis. Based on structural evidence PfHsp70-z belongs to the Hsp110 family of proteins. Since Hsp110 proteins have been described as nucleotide exchange factors (NEFs) of their canonical Hsp70 counterparts, it has been speculated that PfHsp70-z may serve as a NEF of PfHsp70-1. In the current study, P. falciparum cells cultured in vitro were subjected to heat stress, triggering the enhanced expression of PfHsp70-z. Biochemical assays conducted using recombinant PfHsp70-z protein demonstrated that the protein is heat stable and possesses ATPase activity. Furthermore, we observed that PfHsp70-z is capable of self-association. The structural-functional features of PfHsp70-z provide further evidence for its role as a chaperone and possible nucleotide exchange factor of PfHsp70-1.en© 2015 Zininga et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.adenosine triphosphatase;chaperone;heat shock protein 70;controlled study;cross reaction;enzyme activity;gene;gene overexpression;heat stress;heat stress;Hsp70 gene;malaria; nonhuman;Plasmodium falciparum;protein aggregation;protein expression;protein purification;protein secondary structure;structure analysis;temperature;upregulationPlasmodium falciparum;Article