Accession Number : ADA301452

Title :   Structure/Function of Recombinant Human Estrogen Receptor.

Descriptive Note : Annual rept. 1 Sep 94-31 Aug 95,

Corporate Author : CALIFORNIA UNIV IRVINE

Personal Author(s) : Vickery, Larry

PDF Url : ADA301452

Report Date : SEP 1995

Pagination or Media Count : 37

Abstract : The requisite initial step in estrogen receptor action, ligand binding, is mediated by the 250 amino acid Hormone Binding Domain (HBD). We have expressed and purified in high yield (approx 10 mg/liter of culture) two peptides (amino acids 301-551 or 305-551 of the estrogen receptor) in E. coil. Both peptides exhibit high affinity estradiol binding (kd 0.3 nM) and the ability to discriminate among various ligands comparable to the full-length protein. The isolated HBD (301-551) peptide displayed cooperative estradiol binding suggesting that it dimerizes and undergoes conformational changes required for cooperativity in a manner comparable to the full-length protein. In contrast, the HBD (305-551) peptide exhibited cooperativity only at protein concentrations at least 3-fold higher than those required for the longer peptide, suggesting that the N-terminus of the HBD contributes to dimer interactions. Both of the HBD peptides exhibited binding stoichiometries of 0.5 mol estradiol/mol protein, suggesting that the HBD dimer binds a single molecule of estradiol. These results indicate that the use of fragments of the estrogen receptor expressed in E. coll lend insight into the structural features of the protein responsible for its functional properties.

Descriptors :   *PEPTIDES, *CULTURES(BIOLOGY), *AMINO ACIDS, *ESTROGENS, FUNCTIONS, HIGH RATE, HUMANS, INTERACTIONS, STRUCTURAL PROPERTIES, PROTEINS, ESCHERICHIA COLI, LIGANDS, FUNCTIONAL ANALYSIS, SENSE ORGANS, DISCRIMINATE ANALYSIS, DIMERS.

Subject Categories : Biochemistry
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE