Protease expression analysis in recently field-isolated strains of Trypanosoma cruzi: a heterogeneous profile of cysteine protease activities between TC I and TC II major phylogenetic groups

• Published in: Parasitology 2008-08, Vol.135 (9), p.1093-1100
• Main Authors: FAMPA, P., LISBOA, C. V., JANSEN, A. M., SANTOS, A. L. S., RAMIREZ, M. I.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blotting, Western; cruzipain; Cysteine Endopeptidases - genetics; Cysteine Endopeptidases - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Enzymologic - drug effects; General aspects; General aspects and techniques. Study of several systematic groups. Models; Genotype; Genotypes; Heterogeneity; host-parasite interaction; Host-Parasite Interactions - genetics; Invertebrates; Peptide Hydrolases - genetics; Phylogeny; Protease Inhibitors - pharmacology; proteases; Proteinase inhibitors; TCI and TCII genotypes; Trypanosoma cruzi; Trypanosoma cruzi - enzymology; Trypanosoma cruzi - genetics; virulence factors
• ISSN: 0031-1820; 1469-8161
• DOI: 10.1017/S0031182008004587

Protease expression among TCI and TCII field isolates was analysed. Gelatin-containing gels revealed hydrolysis bands with molecular masses ranging from 45 to 66 kDa. The general protease expression profile showed that TCII isolates presented higher heterogeneity compared to TCI. By utilizing protease inhibitors, we showed that all active proteases at acid pH are cysteine-proteases and all proteases active at alkaline pH are metalloproteases. However, the expression of cruzipain, the T. cruzi major cysteine-protease, did not reproduce a heterogeneous TCII cysteine zymogram profile. Dendogram analyses based on presence/absence matrices of proteases and cruzipain bands showed a TCI separation from the TCII group with 50–60% similarity. We suggest that the observed cysteine protease diversification contributes to differential host infection between TCI and II genotypes.