Natively inhibited Trypanosoma brucei cathepsin B structure determined by using an X-ray laser

Science. 2013 Jan 11;339(6116):227-230. doi: 10.1126/science.1229663. Epub 2012 Nov 29.


The Trypanosoma brucei cysteine protease cathepsin B (TbCatB), which is involved in host protein degradation, is a promising target to develop new treatments against sleeping sickness, a fatal disease caused by this protozoan parasite. The structure of the mature, active form of TbCatB has so far not provided sufficient information for the design of a safe and specific drug against T. brucei. By combining two recent innovations, in vivo crystallization and serial femtosecond crystallography, we obtained the room-temperature 2.1 angstrom resolution structure of the fully glycosylated precursor complex of TbCatB. The structure reveals the mechanism of native TbCatB inhibition and demonstrates that new biomolecular information can be obtained by the "diffraction-before-destruction" approach of x-ray free-electron lasers from hundreds of thousands of individual microcrystals.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Catalytic Domain
  • Cathepsin B / antagonists & inhibitors
  • Cathepsin B / chemistry*
  • Crystallization
  • Crystallography, X-Ray
  • Enzyme Precursors / chemistry
  • Glycosylation
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Conformation
  • Protozoan Proteins / antagonists & inhibitors
  • Protozoan Proteins / chemistry*
  • Sf9 Cells
  • Spodoptera
  • Trypanosoma brucei brucei / enzymology*
  • X-Rays


  • Enzyme Precursors
  • Protozoan Proteins
  • Cathepsin B

Associated data

  • PDB/4HWY