Article
Trypanosoma cruzi calmodulin: Cloning, expression and characterization
Registro en:
Vol.123, Nº 4,pp. 326–333
doi:10.1016/j.exppara.2009.08.010
0014-4894
Autor
Garcia-Marchan, Y
Sojo, F
Rodriguez, E
Zerpa, N
Malave, C
Galindo-Castro, I
Salerno, M
Benaím, Gustavo
Institución
Resumen
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 a-helix content upon binding with Ca2+, 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 Ca2+ pump,
showed a significant loss of activity when assayed upon stimulation with the T. cruzi CaM.