Molecular action of tricholin, a ribosome-inactivating protein isolated from Trichoderma viride

Mol Microbiol. 1991 Dec;5(12):3007-13. doi: 10.1111/j.1365-2958.1991.tb01860.x.


An extracellular protein was isolated from a species of soil-borne fungi (Trichoderma viride) and its amino acid composition has been determined. The protein is acidic with a molecular mass of 14,200 daltons and is given the trivial name tricholin. Tricholin is a potent inhibitor of cell-free protein synthesis. When rabbit reticulocyte lysate was incubated with tricholin at a concentration of 6.3 x 10(-7) M, it completely abolished the capacity of the lysate to support protein synthesis. The inhibition appears to be due to its reaction to ribosomes, since it generates a specific cleavage product, an alpha-sarcin RNA fragment, from reticulocyte ribosomal RNA. This reaction to ribosomes mimics that of alpha-sarcin. The antibody of alpha-sarcin strongly cross-reacts with tricholin, while the antibody of tricholin shows a weak reaction with alpha-sarcin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell-Free System / drug effects
  • Fungal Proteins / isolation & purification
  • Fungal Proteins / pharmacology*
  • Protein Synthesis Inhibitors / pharmacology
  • RNA, Ribosomal, 23S / drug effects
  • RNA, Ribosomal, 23S / metabolism
  • Ribosomes / drug effects
  • Ribosomes / metabolism*
  • Trichoderma / chemistry*


  • Fungal Proteins
  • Protein Synthesis Inhibitors
  • RNA, Ribosomal, 23S