Drug Target Validation Methods in Malaria - Protein Interference Assay (PIA) as a Tool for Highly Specific Drug Target Validation

Abstract

This mini review will describe the current state of the antimalarial toolset as well as the potentially druggable malarial pathways. A specific focus is drawn to the initial efforts to exploit oligomerisation surfaces in drug target validation. As alternative to the conventional methods, Protein Interference Assay (PIA) can be used for specific distortion of the target protein function and pathway assessment in vivo.

Identification and Validation of Novel Drug Targets for the Treatment of Plasmodium falciparum Malaria: New Insights

“…In many pathogenic systems, including human malaria, conventional genetic manipulation techniques or small molecule inhibitor approaches do not always provide the desired efficacy [22]. In a number of human pathogens, multiple life cycle stages in different hosts and vectors make both in vitro and in vivo target characterization challenging to approach.…”

“…We have recently proposed a novel promising drug-target validation approach that relies on common feature of all biological systems-oligomerization [22]. Oligomerization is a self-assembly of two or more copies of one protein molecule (or different molecules) into one object.…”

“…Oligomerization may be required for a number of reasons, including the correct active site or cofactor binding site assembly on the oligomeric interface or allosteric regulation. Examples where dimerization is crucial for the formation of active sites on the oligomeric interface include previously mentioned aspartate aminotransferase (AspAT) [22], aspartate transcarbamoylase (ATC), and orotate phosphoribosyl transferase (PfOPRT) [183] from P. falciparum. In addition, the physiological assembly of PfOPRT/PfOPDC heterotetramer was shown to be more effective compared to the monofunctional enzymes [189].…”

“…The recently proposed protein interference assay (PIA) [22] involves the utilization of structural knowledge (data) and mutagenic modification of one (or more) partner proteins in the assembly. These modifications may affect the binding site for a cofactor, catalytic activity, or disrupt the oligomeric interface of the target protein.…”

“…Antimalarial research is not an exception to Harlow-Knapp effect: a limited opportunity for genetic manipulation [22] and complex life cycle of the parasite makes novel drug target validation highly challenging. Similarly to the human kinase research scientists tend to "keep looking under the spot light" among the few already validated targets, such as mitochondrial bc1 complex in malaria (target of the widely used Atovaquone), trying to optimize the existing compounds.…”