1. Trypanosoma cruzi calmodulin: cloning, expression and characterization.
- Author
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Garcia-Marchan Y, Sojo F, Rodriguez E, Zerpa N, Malave C, Galindo-Castro I, Salerno M, and Benaim G
- Subjects
- Animals, Antibodies, Protozoan biosynthesis, Calcium-Transporting ATPases blood, Calmodulin chemistry, Calmodulin genetics, Calmodulin immunology, Chickens, Circular Dichroism, Cloning, Molecular, Electrophoresis, Polyacrylamide Gel, Enzyme Activation, Enzyme-Linked Immunosorbent Assay, Erythrocyte Membrane enzymology, Female, Gene Expression Regulation, Humans, Immunoglobulins biosynthesis, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins immunology, Sequence Alignment, Sequence Analysis, DNA, Trypanosoma cruzi chemistry, Trypanosoma cruzi genetics, Calmodulin biosynthesis, Trypanosoma cruzi metabolism
- Abstract
We have cloned and expressed calmodulin (CaM) from Trypanosoma cruzi, for the first time, to obtain large amounts of protein. CaM is a very well conserved protein throughout evolution, sharing 100% amino acid sequence identity between different vertebrates and 99% between trypanosomatids. However, there is 89% amino acid sequence identity between T. cruzi and vertebrate CaMs. The results demonstrate significant differences between calmodulin from T. cruzi and mammals. First, a polyclonal antibody developed in an egg-yolk system to the T. cruzi CaM recognizes the autologous CaM but not the CaM from rat. Second, it undergoes a larger increase in the alpha-helix content upon binding with Ca(2+), when compared to CaM from vertebrates. Finally, two classic CaM antagonists, calmidazolium and trifluoperazine, capable of inhibiting the action of CaM in mammals when assayed on the plasma membrane Ca(2+) pump, showed a significant loss of activity when assayed upon stimulation with the T. cruzi CaM.
- Published
- 2009
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