Abstract
Cysteine proteases have been identified in parasitic protozoa including the causative agent of Chagas' disease Trypanosoma cruzi. T. cruzi lysates subjected to substrate containing SDS-polyacrylamide gel electrophoresis exhibit major bands of proteolytic activity in the 45-55 kDa molecular mass range (cruzipain activity). Paradoxically, addition of kininogen (a cystatin-like protease inhibitor) to the lysates before electrophoresis results in the appearance of additional bands of proteolytic activity in the 160-190 kDa molecular mass range. This inhibitor-activated protease activity depends upon the reaction conditions and exhibits novel properties. For example, a 24-48 hour preincubation at low temperature (-20°C optimum) greatly enhances the proteolytic activity. The results suggest that a metastable complex forms between kininogen and a cryptic 30 kDa cysteine protease from T. cruzi and that this complex participates in the activation of proteolytic activity.
Original language | English (US) |
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Pages (from-to) | 540-544 |
Number of pages | 5 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 240 |
Issue number | 3 |
DOIs | |
State | Published - Nov 26 1997 |
Externally published | Yes |
Keywords
- Cysteine protease
- Kinetoplastid
- Kininogen
- Trypanosoma cruzi
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology