Studies on metal induced conformation changes in a peripheral blood lymphocyte lectin

Kayestha, Rajeev; Sumati,; Hajela, Krishnan

doi:10.1016/0304-4165(95)00135-2

Cited by 5 publications

(1 citation statement)

References 16 publications

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“…The poor activity recovery by apo-TcMCP-1 might be due to its lower stability, since TcMCP-1 control (dialysed against 50 mM Tris/HCl, pH 7.6) lost almost 50 % of its activity compared with the TcMCP-2 control. It has been suggested for several metalloproteins that removal of the bivalent cation induces conformational changes that result in enzyme inactivation [30,31].…”

Section: Effects Of Metal Ionsmentioning

confidence: 99%

Two metallocarboxypeptidases from the protozoan Trypanosoma cruzi belong to the M32 family, found so far only in prokaryotes

Niemirowicz

Parussini

Agüero

et al. 2006

Biochemical Journal

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MCPs (metallocarboxypeptidases) of the M32 family of peptidases have been identified in a number of prokaryotic organisms, and only a few of them have been characterized biochemically. Members of this family are absent from eukaryotic genomes, with the remarkable exception of those of trypanosomatids. The genome of the CL Brener clone of Trypanosoma cruzi, the causative agent of Chagas' disease, encodes two such MCPs, with 64% identity between them: TcMCP-1 and TcMCP-2. Both genes, which are present in a single copy per haploid genome, were expressed in Escherichia coli as catalytically active polyHis-tagged recombinant enzymes. Despite their identity, the purified TcMCPs displayed marked biochemical differences. TcMCP-1 acted optimally at pH 6.2 on FA {N-(3-[2-furyl]acryloyl)}-Ala-Lys with a K(m) of 166 muM. Activity against benzyloxycarbonyl-Ala-Xaa substrates revealed a P1' preference for basic C-terminal residues. In contrast, TcMCP-2 preferred aromatic and aliphatic residues at this position. The K(m) value for FA-Phe-Phe at pH 7.6 was 24 muM. Therefore the specificities of both MCPs are complementary. Western blot analysis revealed a different pattern of expression for both enzymes: whereas TcMCP-1 is present in all life cycle stages of T. cruzi, TcMCP-2 is mainly expressed in the stages that occur in the invertebrate host. Indirect immunofluorescence experiments suggest that both proteins are localized in the parasite cytosol. Members of this family have been identified in other trypanosomatids, which so far are the only group of eukaryotes encoding M32 MCPs. This fact makes these enzymes an attractive potential target for drug development against these organisms.

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Section: Effects Of Metal Ionsmentioning

confidence: 99%