TY - JOUR
T1 - Characterization and quantification of pyridoxal 5'-phosphate-extracted nuclear progesterone receptor
AU - Chen, Tong J.
AU - MacDonald, Richard G.
AU - Robidoux, William F.
AU - Leavitt, Wendell W.
PY - 1981/10
Y1 - 1981/10
N2 - Pyridoxal phosphate extracts progesterone receptors from the nuclear fraction of hamster uterus. Optimal extraction occurs after 2 h at 2 C with 5 mM pyridoxal phosphate. At millimolar concentrations, pyridoxal phosphate also extracts non-receptor proteins from the nuclei, in amounts equivalent to those released by high salt (0.5 M KO) treatment (~10 mg protein per gram tissue). Thus, although pyridoxal phosphate is a useful probe for studying the interaction of steroid receptors with nuclear components, it does not selectively extract nuclear steroid receptors. The pyridoxal phosphate-extracted nuclear progesterone receptor had a sedimentation coefficient of 3.3S. Upon reduction with sodium borohydride, this species was converted to a 2.5S molecule. Sodium borohydride reduction of the pyridoxal phosphate-extracted nuclear receptor also caused a significant change in the steroid binding specificity of the molecule. The steroid specificity of the unreduced pyridoxal phosphate-extracted nuclear receptor was virtually identical to that of the KCl-extracted nuclear receptor. In contrast, deoxycorticosterone and 5α-pregnanedione competed 3- to 8-fold less effectively with progesterone for binding to the reduced form of pyridoxal phosphate-extracted nuclear receptor as compared to the other receptor forms.
AB - Pyridoxal phosphate extracts progesterone receptors from the nuclear fraction of hamster uterus. Optimal extraction occurs after 2 h at 2 C with 5 mM pyridoxal phosphate. At millimolar concentrations, pyridoxal phosphate also extracts non-receptor proteins from the nuclei, in amounts equivalent to those released by high salt (0.5 M KO) treatment (~10 mg protein per gram tissue). Thus, although pyridoxal phosphate is a useful probe for studying the interaction of steroid receptors with nuclear components, it does not selectively extract nuclear steroid receptors. The pyridoxal phosphate-extracted nuclear progesterone receptor had a sedimentation coefficient of 3.3S. Upon reduction with sodium borohydride, this species was converted to a 2.5S molecule. Sodium borohydride reduction of the pyridoxal phosphate-extracted nuclear receptor also caused a significant change in the steroid binding specificity of the molecule. The steroid specificity of the unreduced pyridoxal phosphate-extracted nuclear receptor was virtually identical to that of the KCl-extracted nuclear receptor. In contrast, deoxycorticosterone and 5α-pregnanedione competed 3- to 8-fold less effectively with progesterone for binding to the reduced form of pyridoxal phosphate-extracted nuclear receptor as compared to the other receptor forms.
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U2 - 10.1016/0022-4731(81)90210-7
DO - 10.1016/0022-4731(81)90210-7
M3 - Article
C2 - 7300322
AN - SCOPUS:0019856332
SN - 0022-4731
VL - 14
SP - 1023
EP - 1028
JO - Journal of Steroid Biochemistry
JF - Journal of Steroid Biochemistry
IS - 10
ER -