Interaction of cycloalkanoprogesterones with mammalian progesterone receptor: binding of pregna-D'-pentaranes in the calf uterine cytosol

Amrita Bhakta, Michelle Herman, Inna S. Levina, V. K. Moudgil

Research output: Contribution to journalArticlepeer-review

Abstract

Pregna-D'-pentaranes (pentaranes) are modified progesterones with demonstrable progestational activity and contraceptive effect. We have examined the steroid binding characteristics of the two newly synthesized progesterone analogs, Pentarane A (16α, 17α-cyclohexanoprogesterone) and Pentarane B (6α-methyl, 16α, 17α-cyclohexanoprogesterone), and studied the nature of their interaction with progesterone receptor (PR) from the chicken oviduct and the calf uterine cytosols. Pregna-D'-pentaranes exhibited no affinity for the chick PR but interacted with the calf uterine PR as did R5020. The pentaranes, however, bound PR less tightly. R5020- or pentarane-bound PR sedimented as an 8S moiety in 8-30% linear glycerol gradients. Thermal transformation of receptor resulted in the reduction of the 8S form, and caused an increase in the binding of R5020-and progesterone-bound PR complexes to DNA-cellulose. The pentarane-bound PR bound poorly, if at all, to DNA-cellulose. Our data suggest that pentaranes exhibit both similarities and differences with natural and synthetic progestins with respect to their interaction with calf uterine PR. The lack of pentarane binding to chicken PR is reminiscent of the general phenomenon that antiprogestins (RU486, ZK98299, and Org 31710 and Org 31806) do not interact with chicken PR. Pentaranes, therefore, represent unique steroid analogs to investigate the molecular mechanism of steroid hormone action.

Original languageEnglish (US)
Pages (from-to)153-161
Number of pages9
JournalMolecular and Cellular Biochemistry
Volume125
Issue number2
DOIs
StatePublished - Aug 1993
Externally publishedYes

Keywords

  • DNA binding
  • progesterone
  • receptors
  • steroid analogues

ASJC Scopus subject areas

  • Molecular Biology
  • Clinical Biochemistry
  • Cell Biology

Fingerprint

Dive into the research topics of 'Interaction of cycloalkanoprogesterones with mammalian progesterone receptor: binding of pregna-D'-pentaranes in the calf uterine cytosol'. Together they form a unique fingerprint.

Cite this