title: Progesterone binding in a clinical isolate of Pseudomonas aeruginosa.
abstract: We have undertaken the characterization of progestin binding component(s) in the cytosol prepared from Pseudomonas aeruginosa isolated from an immunocompromised patient. Incubation of P. aeruginosa cytosol aliquots at 0 degrees C with 20 nM [3H]R5020 (a synthetic progestin) revealed the presence of saturable binding. The [3H]R5020 binding reached an equilibrium after 1 h at 0 degrees C and showed saturation at 30-50 nM with a Kd value of 7.7 nM. At 0 degrees C, beta-mercaptoethanol increased the [3H]R5020 binding by 20% but sodium molybdate had no effect. The [3H]R5020-macromolecular complex was stable for up to 4 h at 37 degrees C. Steroid binding specificity analysis revealed that [3H]R5020 binding could be eliminated in the presence of 2 microM progesterone, estradiol, or dihydrotestosterone but that the synthetic glucocorticoid, triamcinolone acetonide, did not compete. Postlabeling of the cytosol fractions obtained after 10-30% glycerol gradient analysis demonstrated association of the radioactivity with a molecule that sedimented as a 6-8 S protease-sensitive moiety which was unaltered in the presence of RNase or DNase. When cells were grown in the presence of 100 nM progesterone, a 50% inhibition in the number of resulting colonies was observed. In addition to its evolutionary significance, the presence of this steroid binding molecule suggests a potential in the endocrine manipulation in the treatment of infections caused by P. aeruginosa.
authors.affiliation: Department of Biological Sciences, Oakland University, Rochester, Michigan 48309-4401.
authors.forename: S
authors.initials: S
authors.lastname: Mosier
authors.forename: M
authors.initials: M
authors.lastname: Nakao
authors.forename: M
authors.initials: M
authors.lastname: Herman
authors.forename: S K
authors.initials: SK
authors.lastname: Walia
authors.forename: N
authors.initials: N
authors.lastname: Rosenthal
authors.forename: C
authors.initials: C
authors.lastname: Hurd
authors.forename: V K
authors.initials: VK
authors.lastname: Moudgil
mesh_terms: D001665:Binding Sites; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D011374:Progesterone / Q000378:metabolism*; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000378:metabolism*; D014552:Urinary Tract Infections / Q000382:microbiology
chemical_list: D011374:Progesterone