The
synthetic androgen 17 beta-hydroxy-17 alpha-[3H]methyl-4,9,11-estratrien-3-one (
R1881) has been used as photoaffinity label to characterize
androgen receptors in rat prostate, in a human transplantable prostatic
adenocarcinoma (PC-82) and in calf uterus.
Androgen receptors preparations were partially purified either via differential chromatography on
2',5'-ADP-Sepharose (rat prostate), via
anion exchange fast
protein liquid chromatography (rat prostate and PC-82) or via
DNA-cellulose chromatography (calf uterus). Purification factors obtained with the three different methods were: 245, 75 and 40 respectively. Photolabelling of receptor preparations was performed via irradiation with a high pressure
mercury lamp either before or after partial purification.
Polyacrylamide gel electrophoresis under denaturing conditions showed that the
DNA-binding form of the
androgen receptor in calf uterus cytosol is a
protein with a molecular mass of approx 95 kD. The covalent attachment of [3H]
R1881 to the 95 kD
protein could be completely suppressed by a 200-fold molar excess of
dihydrotestosterone. In rat prostate cytosol an
androgen receptor with a molecular mass of approx 50 kD could be photoaffinity labelled with
R1881. A similar size was found for the
androgen receptor in the human prostatic
adenocarcinoma. Our results show that photoaffinity labelling of
androgen receptors with [3H]
R1881 as
ligand can be applied for characterization of partial purified
androgen receptor preparations.