title: Trypanosoma cruzi calmodulin: cloning, expression and characterization.
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.
authors.affiliation: Centro de Biociencias y Medicina Molecular, Instituto de Estudios Avanzados (IDEA), Universidad Central de Venezuela, Caracas 1080, Bolivarian Republic of Venezuela.
authors.forename: Yael
authors.initials: Y
authors.lastname: Garcia-Marchan
authors.forename: Felipe
authors.initials: F
authors.lastname: Sojo
authors.forename: Evelyn
authors.initials: E
authors.lastname: Rodriguez
authors.forename: Noraida
authors.initials: N
authors.lastname: Zerpa
authors.forename: Caridad
authors.initials: C
authors.lastname: Malave
authors.forename: Ivan
authors.initials: I
authors.lastname: Galindo-Castro
authors.forename: Milena
authors.initials: M
authors.lastname: Salerno
authors.forename: Gustavo
authors.initials: G
authors.lastname: Benaim
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis; D000252:Calcium-Transporting ATPases / Q000097:blood; D002147:Calmodulin / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D002645:Chickens; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004797:Enzyme-Linked Immunosorbent Assay; D004910:Erythrocyte Membrane / Q000201:enzymology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014349:Trypanosoma cruzi / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000913:Antibodies, Protozoan; D002147:Calmodulin; C016512:IgY; D007136:Immunoglobulins; D011994:Recombinant Proteins; D000252:Calcium-Transporting ATPases