Characterization of the Artemisinin Binding Site for Translationally Controlled Tumor Protein (TCTP) by Bioorthogonal Click Chemistry

Bioconjug Chem. 2016 Dec 21;27(12):2828-2833. doi: 10.1021/acs.bioconjchem.6b00556. Epub 2016 Nov 18.

Abstract

Despite the fact that multiple artemisinin-alkylated proteins in Plasmodium falciparum have been identified in recent studies, the alkylation mechanism and accurate binding site of artemisinin-protein interaction have remained elusive. Here, we report the chemical-probe-based enrichment of the artemisinin-binding peptide and characterization of the artemisinin-binding site of P. falciparum translationally controlled tumor protein (TCTP). A peptide fragment within the N-terminal region of TCTP was enriched and found to be alkylated by an artemisinin-derived probe. MS2 fragments showed that artemisinin could alkylate multiple amino acids from Phe12 to Tyr22 of TCTP, which was supported by labeling experiments upon site-directed mutagenesis and computational modeling studies. Taken together, the "capture-and-release" strategy affords consolidated advantages previously unavailable in artemisinin-protein binding site studies, and our results deepened the understanding of the mechanism of protein alkylation via heme-activated artemisinin.

MeSH terms

  • Alkylation
  • Artemisinins / metabolism*
  • Binding Sites
  • Click Chemistry / methods*
  • Heme / chemistry
  • Mass Spectrometry
  • Molecular Docking Simulation
  • Mutagenesis, Site-Directed
  • Plasmodium falciparum / chemistry*
  • Protozoan Proteins / chemistry*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism*
  • Reproducibility of Results

Substances

  • Artemisinins
  • Protozoan Proteins
  • Heme
  • artemisinin