Identification of an enolase protein in Sarcocystis neurona by the use of two-dimensional electrophoresis and MALDI-ToF analysis.

摘要

Equine protozoal myeloencephalitis is a neurological disease caused by Sarcocystis neurona, an apicomplexan parasite. Sarcocystis neurona is also associated with EPM-like diseases in marine and small mammals as well. The mechanisms of transmission and ability to infect a wide host range remain obscure; therefore, characterization of essential proteins may provide helpful evolutionary information and allow development of novel chemotherapeutics that target non-mammalian biochemical pathways. In the current study two-dimensional electrophoresis and matrix-assisted laser desorption ionization-time of flight (MALDI-ToF) mass spectrometry were combined to characterize and identify an enolase protein from S. neurona based on peptide homology to the Toxoplasma gondii protein. Enolase is thought to be a vestigial, nonphotosynthetic protein resulting from an evolutionary endosymbiosis event of an apicomplexan ancestor with green algae. Enolase has also been suggested to play a role in parasite stage conversion for T. gondii. Characterization of this protein in S. neurona and comparison to other protozoans indicate biochemical similarity of S. neurona enolase to other tissue-cyst forming coccidians that cause encephalitis.