The subunit structure of human breast cancer progesterone receptors: characterization by chromatography and photoaffinity labeling.

摘要: We have partially purified the progesterone receptors (PR) from T47D human breast cancer cells and show that they consist of at least two hormone-binding proteins dissimilar size unequal DNA-binding forms with electrophoretic properties analogous to A B subunits chick oviduct PR. Cytosols were labeled progestin [3H]R5020 in presence or absence unlabeled R5020, samples parallel incubations chromatographed on DEAE-cellulose. large heterogeneous peak specific R5020 binding eluted between 0.1 0.2 M KCl. Pooled fractions this resolved phosphocellulose into peaks: an acidic moiety eluting 0.15 KCl, a more basic one Both sediment approximately 4.1S sucrose density gradients. To test DNA capacity, studies performed. First, ammonium sulfate-precipitated applied DNA-cellulose; half radioactivity was retained. Second, separate DNA-cellulo...