title: The identification of a sequence related to apicomplexan enolase from Sarcocystis neurona.
abstract: Equine protozoal myeloencephalitis (EPM) is a neurological disease caused by Sarcocystis neurona, an apicomplexan parasite. S. neurona is also associated with EPM-like diseases in marine and small mammals. The mechanisms of transmission and ability to infect a wide host range remain obscure; therefore, characterization of essential proteins may provide evolutionary information allowing the 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, non-photosynthetic 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 a biochemical similarity of S. neurona enolase to other tissue-cyst forming coccidians that cause encephalitis.
authors.affiliation: Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Wilson
authors.forename: J J
authors.initials: JJ
authors.lastname: Thelen
authors.forename: J
authors.initials: J
authors.lastname: Lakritz
authors.forename: C R
authors.initials: CR
authors.lastname: Brown
authors.forename: A E
authors.initials: AE
authors.lastname: Marsh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004679:Encephalomyelitis / Q000469:parasitology*; D006801:Humans; D008969:Molecular Sequence Data; D018688:Neospora / Q000201:enzymology / Q000235:genetics; D010751:Phosphopyruvate Hydratase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012522:Sarcocystis / Q000201:enzymology*; D012523:Sarcocystosis / Q000469:parasitology*; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D015800:Protozoan Proteins; D010751:Phosphopyruvate Hydratase