Conformational transitions of the estrogen receptor monomer. Effects of estrogens, antiestrogen, and temperature.

摘要: The technique of aqueous two-phase partitioning has been used to study changes in estrogen receptor (ER) structure that occur upon ligand binding and/or heating vitro. Studies with steroidal and nonsteroidal ligands indicate the difference properties between unoccupied nontransformed ER is due a ligand-induced change this conformation protein. Furthermore, conformational only partially induced by 4-OH-tamoxifen. Although 4-OH-tamoxifen complexes can be transformed heat, there are significant differences transformation process for receptors bound versus estrogenic ligands. A kinetic analysis indicates follows apparent first order kinetics, but 2.5-fold slower 4-OH-tamoxifen-receptor complex. Direct causes structure. Ligand heat-altered results further alteration Experiments using polyethylene glycol palmitate ligand-binding transition associated reduction hydrophobic characteristics receptor. These demonstrate number independent within monomeric steroid-binding subunit exposure elevated temperature