title: [Physico-chemical properties and amino acid composition of a highly purified preparation of a specific estrogen-binding protein of the rat liver].
abstract: The structure and properties of an unusual estrogen-binding protein (UEBP) from male rat liver that was purified by affinity adsorption chromatography was studied. A high degree of purity of UEBP (greater than 99%) associated with appreciable microheterogeneity was demonstrated. The latter seems to be due to partial proteolysis of the protein at the N-end in the course of the isolation procedure. The purified UEBP molecules have the following characteristics: Mr = 31 000 (data from SDS-PAAG electrophoresis), sedimentation coefficient 3.75 S, Stockes'radius 25.6 A, friction coefficient ratio 1.11. The protein absorbance maximum in the UV region lies at 276 nm; extinction coefficient--26, alpha-helix content is 25-30%. The value of equilibrium association constant for estradiol is 5 X 10(7) M-1. Estriol (greater than 100%) and, in a weaker degree, estrone and testosterone (approximately 10%) compete for the binding sites with [3H]estradiol; androsterone has no competitive effect. The amino acid composition of UEBP was determined. The protein was shown to possess a great number of residues carrying hydrophobic side groups (34.4%) and more acidic amino acids over basic ones as well as a low content of cystein, threonine and histidine.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000032:analysis* / Q000302:isolation & purification; D002848:Chromatography, DEAE-Cellulose; D004591:Electrophoresis, Polyacrylamide Gel; D004958:Estradiol / Q000378:metabolism; D007122:Immunoelectrophoresis; D007700:Kinetics; D008099:Liver / Q000032:analysis*; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D011960:Receptors, Estrogen
chemical_list: D000596:Amino Acids; D002352:Carrier Proteins; D011960:Receptors, Estrogen; C010140:estrophilin; D004958:Estradiol
vernacular_title: Fiziko-khimicheskie svoĭstva i aminokislotnyĭ sostav vysokoochishchennogo preparata osobogo éstrogensviazyvaiushchego belka pecheni krys.