Conversion from 4S androgen receptor from rat submandibular gland to higher molecular form and the effect of sodium...

The androgen receptor from rat submandibular gland was transformed by exposure to ATP at 0 degrees C. The transformed 4 S receptor converted to a higher molecular weight form in a low-salt glycerol gradient centrifugation when ATP was removed from the sample. The sedimentation coefficient of the converted receptor was similar in the absence or presence of 20 mM molybdate; 7.8 +/- 0.5 S without molybdate and 7.6 +/- 0.3 S with molybdate. However, the receptor converting in the presence of molybdate could markedly bind to DNA-cellulose, while an entity without molybdate could not. These results suggest that molybdate directly interacts with the DNA-binding domain on the 4 S androgen receptor and prevents this domain from being concealed by conversion in low-salt conditions.