Structure and dynamic behavior of T oll‐like receptor 2 subfamily triggered by malarial glycosylphosphatidylinositols of P lasmodium falciparum

Proinflammatory responses by T oll‐like receptors ( TLR s) to malaria infection are considered to be a significant factor in suppressing pathogen growth and in disease control. The key protozoan parasite P lasmodium falciparum causes malaria through glycosylphosphatidylinositols ( GPI s), which induce the host immune response mainly via TLR 2 signalling. Experimental studies have suggested that malarial GPI s from P . falciparum are recognized by the TLR 2 subfamily. However, the interaction site and their involvement in the activation mechanism are still unknown. A better understanding of the detailed structure of the TLR – GPI interaction is important for the design of more effective anti‐malarial therapeutics. We used a molecular docking method to predict the binding regions of malarial GPI s with the TLR 2 subfamily members. We also employed molecular dynamics simulations and principal component analysis to understand ligand‐induced conformational changes of the TLR 2 subfamily. We observed the expected structural changes upon ligand binding, and significant movements were found in loop regions located in the ligand‐binding site of the TLR 2 subfamily. We further propose that the binding modes of malarial GPI s are similar to lipopeptides, and that the lipid portions of the ligands could play an essential role in selective dimerization of the TLR 2 subfamily.