Progesterone binding in a clinical isolate of Pseudomonas aeruginosa

Autor: Michelle Herman, Mokoto Nakao, Cliff Hurd, Virinder K. Moudgil, Susan Mosier, Walia Sk, Nancy Rosenthal
Rok vydání: 1991
Předmět:
Zdroj: Archives of Biochemistry and Biophysics. 287:160-166
ISSN: 0003-9861
DOI: 10.1016/0003-9861(91)90401-4
Popis: 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.
Databáze: OpenAIRE