Heterogeneity of metalloprotease expression inTrypanosoma cruzi

Abstract

SUMMARYExpression of metalloprotease activities during metacyclogenesis of a series of strains and clones ofTrypanosoma cruziwas investigated using SDS-polyacrylamide gel electrophoresis with a range of different co-polymerized proteolytic substrates. A complex pattern of metalloprotease expression, with considerable quantitative and qualitative variability between strains and life-cycle stages, was apparent. This is in contrast to previously published data, and data presented in this study, which demonstrate a high degree of conservation of expression of cysteine proteases in different strains and clones ofT. cruzi. All the metalloprotease activities identified partitioned into the detergent phase of a Triton X-114 extract, suggesting that they are membrane-bound. Developmental regulation of expression during metacyclogenesis, either in terms of quantity, or in terms of difference in relative amounts of different isoforms, was apparent for all isolates studied except CL14. However, a clearly metacyclic-specific/metacyclic-enriched metalloprotease was detected only inT. cruziDm28c and 383, and our results demonstrate that a metacyclic-specific metalloprotease common to all isolates of the parasite could not be detected, at least at this level of analysis.