Physico-chemical properties of the hydroxysterol binding protein of human lymphocyte cytosol. Effects of high salt concentrations and molybdate.
FEBS Lett
; 173(2): 319-26, 1984 Aug 06.
Article
in En
| MEDLINE
| ID: mdl-6745440
ABSTRACT
Side chain-hydroxylated derivatives of cholesterol (OH sterol) inhibiting lymphoblastic transformation bind with high affinity and specificity to a hydroxysterol binding protein (OHSBP) in the cytosol of human lymphocytes. These binding properties of OHSBP suggested some analogies with that of steroid hormone receptors. The observation of a nuclear binding of 25-OH[3H]cholesterol prompted us to apply to the cytosolic OH sterol-OHSBP complex the physico-chemical treatments known to 'activate' the steroid hormone receptors. A change of sedimentation coefficient from 8.3 to 4.3 S was observed in hypertonic buffer (0.4 M KCl) but the resulting 4.3 S complex dissociates easily whereas the 'native' 8.3 S form does not. Moreover, molybdate did not prevent the 8.3----4.3 S transformation induced by KCl and neither ammonium sulfate precipitation nor increasing temperature had any effect on the sedimentation coefficient of the 8.3 S complex. Thus, several physico-chemical features differentiate the OH sterol-OHSBP complex from steroid hormone receptors.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Lymphocytes
/
Carrier Proteins
/
Molybdenum
Limits:
Humans
Language:
En
Journal:
FEBS Lett
Year:
1984
Type:
Article