title: Heat-shock response in Legionella pneumophila.
abstract: The heat-shock response of Legionella pneumophila was examined by radiolabelling bacterial cell proteins with [35S]methionine following a temperature shift from 30 to 42 degrees C. Five heat-shock proteins were identified as having molecular masses of 17, 60, 70, 78, and 85 kilodaltons (kDa). The 85- and 60-kDa proteins were equally distributed between supernatant and pellet fractions following ultracentrifugation at 100,000 x g, the 70- and 78-kDa proteins were found primarily in the supernatant, and the 17-kDa protein was found primarily in the pellet. Synthesis of subsets of the heat-shock proteins could be stimulated by novobiocin, patulin, or puromycin. Ethanol, an effector of the heat-shock response in other microorganisms, had little effect on L. pneumophila, even at the highest concentration tolerated by the bacterial cells (1.9%). Finally, the 60-kDa heat-shock protein of L. pneumophila was immunologically cross-reactive with a polyclonal antibody prepared to the Escherichia coli groEL protein. However, a mouse monoclonal antibody reactive with the 60-kDa protein of all legionellae tested did not cross-react with the E. coli groEL protein, suggesting that the Legionella 60-kDa protein contains common and unique epitopes.
authors.affiliation: Research Service, W.J.B. Dorn Veterans Hospital, Columbia, SC 29201.
authors.forename: M W
authors.initials: MW
authors.lastname: Lema
authors.forename: A
authors.initials: A
authors.lastname: Brown
authors.forename: C A
authors.initials: CA
authors.lastname: Butler
authors.forename: P S
authors.initials: PS
authors.lastname: Hoffman
mesh_terms: D000937:Antigen-Antibody Reactions; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000276:immunology / Q000302:isolation & purification; D018834:Chaperonin 60; D004250:DNA Topoisomerases, Type II / Q000276:immunology; D000431:Ethanol / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000276:immunology / Q000302:isolation & purification; D015151:Immunoblotting; D007875:Legionella / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D008970:Molecular Weight; D009675:Novobiocin / Q000494:pharmacology; D011233:Precipitin Tests
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D009675:Novobiocin; D000431:Ethanol; D004250:DNA Topoisomerases, Type II