alpha-Fetoprotein is not a component of the estradiol receptor of the rat uterus.
- 1 June 1977
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 74 (6), 2269-2272
- https://doi.org/10.1073/pnas.74.6.2269
Abstract
In high-salt medium, cytosol from immature rat uteri displays 2 main high-affinity estradiol-binding peaks after ultracentrifugation in a sucrose gradient. The 2 components are the estradiol receptor which has a sedimentation coefficient of 5.5 S, and the .alpha.-fetoprotein which sediments at 4.5 S. The dissociation rate constants (k-1) of plasma .alpha.-fetoprotein-estradiol complexes measured at 0.degree. C in the absence or presence of 0.4 M KCl were found to be 7 .times. 10-5 and 8 .times. 10-5 s-1, respectively. The half-time of dissociation of these hormone-plasma protein complexes is 100-200 times more rapid than that of the estradiol-receptor complexes. These data led to the use of 2 differential dissociation methods for the measurement of the hormone-binding protein complexes. In a high-salt cytosol, the charcoal technique measured selectively the receptor binding sites; the hydroxylapatite technique measured the sum of the .alpha.-fetoprotein plus receptor binding sites. Under these conditions, binding specificity studies provided evidence that .alpha.-fetoprotein is not a subunit of the receptor. This was confirmed by binding specificity studies in high-salt medium of the receptor separated from .alpha.-fetoprotein by ultracentrifugation.This publication has 25 references indexed in Scilit:
- Comparison of the binding of [2,4,6,7-3H] estradiol-17β [E23H] to the immature rat uterus under in vivo, in vitro and “cell-free” conditions—I. Some characteristics of the cytoplasmic estradiol-receptor complexThe Journal of Steroid Biochemistry and Molecular Biology, 1976
- Rat alpha-fetoprotein: isolation, characterization and estrogen-binding propertiesBiochimie, 1974
- Purification of estradiol receptor by affinity chromatography. Representative experimentsFEBS Letters, 1973
- A comparison of the estrone-estradiol-binding proteins in the plasmas of prepubertal and pregnant ratsSteroids, 1972
- Etude des constantes de liaison entre les oestrogenes et 1'α1‐foetoproteine de ratFEBS Letters, 1972
- Rat Estradiol Binding Plasma Protein (EBP)Steroids, 1971
- Effect of KCl, CaCl2, tempcrature and œstradiol on the uterine cytosol receptor of œstradiolBiochimie, 1971
- Properties of a uterine oestradiol receptorBiochemical and Biophysical Research Communications, 1968
- A two-step mechanism for the interaction of estradiol with rat uterus.Proceedings of the National Academy of Sciences, 1968
- A receptor molecule for estrogens: studies using a cell-free system.Proceedings of the National Academy of Sciences, 1967