Structure and dynamic behavior of Toll‐like receptor 2 subfamily triggered by malarial glycosylphosphatidylinositols of Plasmodium falciparum

• Published in: The FEBS journal Vol. 280; no. 23; pp. 6196 - 6212
• Main Authors: Durai, Prasannavenkatesh, Govindaraj, Rajiv Gandhi, Choi, Sangdun
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.12.2013; Published by Blackwell Pub. on behalf of the Federation of European Biochemical Societies
• Subjects: Amino Acid Sequence; Animals; Binding Sites; Catalytic Domain; glycosylphosphatidylinositol; Glycosylphosphatidylinositols - chemistry; Glycosylphosphatidylinositols - metabolism; Humans; Malaria; Malaria, Falciparum - immunology; Mice; Models, Molecular; molecular docking; Molecular Dynamics Simulation; Molecular Sequence Data; Original; Parasites; Pathogens; Plasmodium falciparum; Plasmodium falciparum - immunology; Plasmodium falciparum - metabolism; Principal Component Analysis; Protein Conformation; Sequence Homology, Amino Acid; Signal Transduction; Toll-Like Receptor 2 - chemistry; Toll-Like Receptor 2 - metabolism; Toll‐like receptor; molecular docking; glycosylphosphatidylinositol; Toll-like receptor; principal component analysis; molecular dynamics simulation
• ISSN: 1742-464X; 1742-4658
• DOI: 10.1111/febs.12541

Proinflammatory responses by Toll‐like receptors (TLRs) to malaria infection are considered to be a significant factor in suppressing pathogen growth and in disease control. The key protozoan parasite Plasmodium falciparum causes malaria through glycosylphosphatidylinositols (GPIs), which induce the host immune response mainly via TLR2 signalling. Experimental studies have suggested that malarial GPIs from P. falciparum are recognized by the TLR2 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 GPIs with the TLR2 subfamily members. We also employed molecular dynamics simulations and principal component analysis to understand ligand‐induced conformational changes of the TLR2 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 TLR2 subfamily. We further propose that the binding modes of malarial GPIs are similar to lipopeptides, and that the lipid portions of the ligands could play an essential role in selective dimerization of the TLR2 subfamily. Structural understanding of the TLR‐GPI interaction is significant for the design of effective anti‐malarial therapeutics. We adopted molecular docking method, molecular dynamics simulations and principal component analysis to predict the sites where malarial GPIs bind and to understand the GPIs‐induced conformational changes of the TLR2 subfamily. We witnessed the anticipated structural changes of the TLR2 subfamily upon ligand binding.