Purification and characterization of a metacestode cysteine proteinase from Taenia solium involved in the breakdown of human IgG

S. Baig, R. T. Damian, J. L. Molinari, P. Tato, J. Morales-Montor, M. Welch, J. Talhouk, R. Hashmey, A. C. White

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Infection of the central nervous system by Taenia solium cysticerci is the cause of human neurocysticercosis, a major neurological infection in the Third World and an emerging infectious disease in the United States. We previously isolated a cysteine proteinase from cysticerci of Taenia crassiceps and demonstrated that it degrades human IgG in vitro. We have now isolated a 48 kDa thiol-dependent proteinase from T. solium. The T. solium enzyme also degrades human IgG, but does not significantly degrade albumin. IgG degradation was inhibited by cysteine proteinase inhibitors, but not significantly by inhibitors of aspartic, serine, or metalloproteinases. The peptide substrate specificity and pH optimum resemble cathepsin L. The Km for the peptide substrate Z-Phe-Arg-AFC was calculated to be 7.0 × 10-6 M, the Kcat was 1.98 × 105 s-1, and the Kcat/Km 2.84 × 10 9 M-1 s-1, a value which is within the diffusion control limit for highly catalytic enzymes. We propose that immunoglobulin degradation by the T. solium cysteine proteinase may play a key role in the host-parasite interface and could be employed as a target for chemotherapy.

Original languageEnglish (US)
Pages (from-to)411-416
Number of pages6
JournalParasitology
Volume131
Issue number3
DOIs
StatePublished - Sep 2005

Keywords

  • Cysteine proteinase
  • Cysticercosis
  • Immunoglobulin
  • Taenia crassiceps
  • Taenia solium

ASJC Scopus subject areas

  • Parasitology
  • Animal Science and Zoology
  • Infectious Diseases

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    Baig, S., Damian, R. T., Molinari, J. L., Tato, P., Morales-Montor, J., Welch, M., Talhouk, J., Hashmey, R., & White, A. C. (2005). Purification and characterization of a metacestode cysteine proteinase from Taenia solium involved in the breakdown of human IgG. Parasitology, 131(3), 411-416. https://doi.org/10.1017/S0031182005007821