Two novel IgG endopeptidases of Streptococcus equi

Research output: Contribution to journalArticle


Streptococcus equi ssp. equi causes strangles, a highly contagious and serious disease in the upper respiratory tract of horses. Streptococcus equi ssp. zooepidemicus, another subspecies of this genus, is regarded as an opportunistic commensal in horses. The present study describes the characterization of two novel immunoglobulin G (IgG) endopeptidases of these subspecies, IdeE2 and IdeZ2. Both enzymes display sequence similarities with two previously characterized IgG endopeptidases, IdeE of S. equi ssp. equi and IdeZ of S. equi ssp. zooepidemicus. IdeE2 and IdeZ2 display high substrate-specificity in comparison with IdeE and IdeZ, as they both completely cleave horse IgG, while the activity against IgG from mouse, rabbit, cat, cow, sheep and goat is low or absent. The potential use of IdeE and IdeE2 as vaccine components was studied in a mouse infection model. In this vaccination and challenge study, both enzymes induced protection against S. equi ssp. equi infection.


  • Greta Hulting
  • Margareta Flock
  • Lars Frykberg
  • Jonas Lannergård
  • Jan-Ingmar Flock
  • Bengt Guss
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Microbiology in the medical area


  • vaccine, IgG endopeptidases, IdeS, IdeZ, Streptococcus equi, IdeE
Original languageEnglish
Pages (from-to)44-50
JournalFEMS Microbiology Letters
Issue number1
Publication statusPublished - 2009
Publication categoryResearch