Reduced pH causes structural changes in the potent mitogenic toxin of Pasteurella multocida

FEMS Microbiol Lett. 1999 Nov 1;180(1):15-20. doi: 10.1111/j.1574-6968.1999.tb08772.x.


Pasteurella multocida toxin is a potent mitogen that is believed to act intracellularly. On transverse urea gradient gels at pH 8.0 the toxin displayed one major unfolding transition at 4 M urea. However, at pH 6.1 the unfolding transition took place at 3.5 M urea. Circular dichroism spectra also indicated that a structural change took place at acidic pH. In addition it was found that the toxin that had been denatured in 8 M urea refolded in solution with a high recovery of biological activity. These findings are discussed in terms of the likely domain structure of the P. multocida toxin.

MeSH terms

  • 3T3 Cells
  • Animals
  • Bacterial Proteins*
  • Bacterial Toxins / chemistry*
  • Circular Dichroism
  • Electrophoresis, Gel, Pulsed-Field
  • Mice
  • Protein Denaturation
  • Protein Folding
  • Urea


  • Bacterial Proteins
  • Bacterial Toxins
  • Pasteurella multocida toxin
  • Urea