CHROMATOGRAPHIC RESOLUTION OF THE TYPE-II ESTROGEN-BINDING SITE AND ATYROSINASE-LIKE ENZYMATIC-ACTIVITY FROM RAT UTERINE NUCLEI

Citation
Cl. Densmore et al., CHROMATOGRAPHIC RESOLUTION OF THE TYPE-II ESTROGEN-BINDING SITE AND ATYROSINASE-LIKE ENZYMATIC-ACTIVITY FROM RAT UTERINE NUCLEI, Steroids, 59(4), 1994, pp. 282-287
Citations number
22
Categorie Soggetti
Biology,"Endocrynology & Metabolism
Journal title
ISSN journal
0039128X
Volume
59
Issue
4
Year of publication
1994
Pages
282 - 287
Database
ISI
SICI code
0039-128X(1994)59:4<282:CROTTE>2.0.ZU;2-0
Abstract
Nuclear extracts from estradiol-treated rat uteri which contain type I I estrogen binding sites have recently been found to also contain a ty rosinase-like estradiol metabolizing activity. A recent study suggeste d that both the binding and enzymatic activities are significantly inc reased in the presence of micromolar concentrations of copper and asco rbate, display a number of common biochemical sensitivities, and share similar ligand/substrate binding affinities. Levels of both activitie s are significantly increased in uterus in response to hormone (estrog en) stimulation. These and other similarities indicate a possible rela tionship between the enzymatic and binding activities, A detailed chro matographic examination of these two activities in the present study r evealed that while the type II sites and estradiol metabolizing activi ty exhibited virtually identical chromatographic properties on DEAE-hi gh-performance liquid chromatography they are readily resolved on othe r chromatographic matrices, including phosphocellulose, DNA-cellulose, and S-Sepharose. These results demonstrate that type II binding sites are distinct from the tyrosinase-like enzyme activity previously desc ribed in rat uterine nuclear extracts.