Sex steroid binding protein in the plasma of Macaca nemestrina
| Autor: | Harvey S. Schiller, Philip H. Petra |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Male
Tris medicine.medical_specialty Polyacrylamide Diethylstilbestrol Estrone Biology Biochemistry Structure-Activity Relationship chemistry.chemical_compound Sex Factors Endocrinology Pregnancy Sex Hormone-Binding Globulin Internal medicine medicine Animals Binding site Macaca nemestrina Dihydrotestosterone Estriol Haplorhini Kinetics Electrophoresis chemistry Female medicine.drug |
| Zdroj: | Journal of Steroid Biochemistry. 8:655-661 |
| ISSN: | 0022-4731 |
| DOI: | 10.1016/0022-4731(77)90293-x |
| Popis: | A sex steroid binding protein (nSBP) has been identified in the plasma of Macaco nemestrina. The protein specifically binds 5α-androstane-17β-ol,3-one (KA(male) = 1.87 ± 1.05 × 109 M−1, KA(female) = 2.04 ± 0.88 × 109 M−1, KA(pregnancy) = 2.21 ± 0.59 × 109 M−1; 4°, 10 mM Tris, pH 7.4), testosterone (KA = 4.10 ± 2.50 × 108 M−1, 4°, 10 mM Tris, pH 7.4), and estradiol-17β (2.41 ± 1.34 × 108 M−1, 4°, 10 mM Tris, pH 7.4). The steroids bind to the protein at the same site. Progesterone, cortisol, estrone, estriol, and diethylstilbestrol have relatively low affinity for the binding site. Specificity studies also suggest that 5α-androstane derivatives with a 3α-hydroxyl show little affinity compared with those having 3β-hydroxyl. Electrophoresis in 5% polyacrylamide gels yields one active molecular species with RF 0.32. The rate constant of dissociation of the DHT-nSBP complex at 4° and pH 7.4 is 0.013 min−1 with a half-time of 52.8 min. The binding capacity of nSBP expressed in μg 5α-androstane-17β-ol,3-one bound/100ml plasma for males (5 samples) and females (7 samples) is 5.62 ± 1.24 (S.D.) and 11.07 ± 1.85 (S.D.), respectively (P < 0.001). These results show that nSBP and human SBP are quite similar in their binding and structural properties and therefore establish Macaca nemestrina as a good animal model to study the physiological role of SBP. |
| Databáze: | OpenAIRE |
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