Abstract
The kinetics of the interaction between recombinant human estrogen receptor and chicken vitellogenin gene II estrogen response element (ERE) were determined by ERE-Sepharose chromatography. The association constant of the interaction between the ERE and the human estrogen receptor was dependent on receptor concentration, estradiol binding and temperature. The highest association constant (80-100 x 106 M-1) was measured for the estradiol-bound receptor prepared at 250°C and at concentrations higher than 7 nM. At high receptor concentrations (>7nM) the binding mechanism of estradiol to the receptor was positive cooperative, indicating receptor homodimerization. At lower concentrations the binding mechanism was partially cooperative and the association constant of the liganded receptor was significantly lower. The binding mechanism at 4°0C was cooperative as well, and the association constants were similarly dependent upon receptor concentration, but were 50% lower than the receptor prepared at 25°C. The association constant of the unliganded receptor was 4- to 5-fold lower than that of the liganded receptor at 25°C. These data suggest that in addition to estradiol-induced conformational changes in the receptor, the receptor dimers are subjected to temperature-dependent changes, which further increase their affinity for an ERE.
| Original language | English |
|---|---|
| Pages (from-to) | 153-159 |
| Number of pages | 7 |
| Journal | Journal of Steroid Biochemistry and Molecular Biology |
| Volume | 57 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Feb 1996 |
Bibliographical note
Funding Information:Survey of Israel) for his help in performing phosphorous analysis of the ERE-Sepharose. This work was supported in part by grants from the Israel Ministry of Health, The Israel Cancer Association (S.S.) and grants HD06707 and ES01247 from The National Institutes of Health (A.C.N.).