title: Continued proteomic analysis of Mycobacterium leprae subcellular fractions.
abstract: Recently the sequence of the Mycobacterium leprae chromosome, the only known obligate intracellular mycobacterium, was completed. It has a dramatic reduction in functional genes, with a coding capacity of only 49.5%, the lowest one so far observed among bacterial genomes. The leprosy bacillus seems to preserve a minimal set of genes that allows its survival in the host. The identification of genes that are actually expressed by the bacterium is of high significance in the context of mycobacterial pathogenesis. In this current study, a proteomic approach was undertaken to identify the proteins present in the soluble/cytosol and membrane subcellular fractions obtained from armadillo derived M. leprae. Proteins from each fraction were separated by two-dimensional gel electrophoresis (2-DE) and identified by mass spectrometry. A total of 147 protein spots were identified from 2-DE patterns and shown to comprise products of 44 different genes, twenty eight of them corresponding to new proteins. Additionally, two highly basic proteins (with pI >10.0) were isolated by heparin affinity chromatography and identified by N-terminal sequencing. This study constitutes the first application of proteomics to a host-derived Mycobacterium.
authors.affiliation: Department of Microbiology, Colorado State University, Fort Collins, CO 80523-1682, USA.
authors.forename: Maria Angela M
authors.initials: MA
authors.lastname: Marques
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Espinosa
authors.forename: Erika K
authors.initials: EK
authors.lastname: Xavier da Silveira
authors.forename: Maria Cristina V
authors.initials: MC
authors.lastname: Pessolani
authors.forename: Alex
authors.initials: A
authors.lastname: Chapeaurouge
authors.forename: Jonas
authors.initials: J
authors.lastname: Perales
authors.forename: Karen M
authors.initials: KM
authors.lastname: Dobos
authors.forename: John T
authors.initials: JT
authors.lastname: Belisle
authors.forename: John S
authors.initials: JS
authors.lastname: Spencer
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Brennan
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D002846:Chromatography, Affinity; D003600:Cytosol / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D016680:Genome, Bacterial; D013058:Mass Spectrometry; D009166:Mycobacterium leprae / Q000378:metabolism*; D020543:Proteome; D040901:Proteomics / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D020543:Proteome