Partial purification of nuclear androgen receptor by micrococcal nuclease digestion of chromatin and hydrophobic interaction chromatography.

Extensive (20%) digestion of linker DNA of prostatic chromatin with micrococcal nuclease resulted in the precipitation of 95% of the nuclear androgen receptors. The receptor-enriched precipitate was dissolved in Tes buffer, pH 7.0, containing 0.6--1.2 M NaCl and analysed by hydrophobic interaction chromatography. The adsorption of receptor to omega-amino-alkyl derivatives of agarose increased with the length of the alkyl substituent indicating the presence of hydrophobic regions on the surface of the receptor molecule. Digestion of linker DNA followed by chromatography of precipitated chromatin proteins using 5-aminohexyl-agarose gave rise to a mean 93-fold purificaton of receptor with a recovery of 45%. This approach to the partial separation of nuclear androgen receptor may prove useful in conjunction with more selective purification techniques such as affinity chromatography.