Sex steroid binding proteins

A. Orstan, M. F. Lulka, B. Eide, P. H. Petra, and J. B. A. Ross, The steroid-binding site of human and rabbit sex steroid-binding protein of plasma Fluorescence characterization with... 

Thyroid hormones and most steroid hormones are associated with carrier proteins in the serum. The carrier proteins are called, appropriately, thyroxine-binding globulin, transcortin (for cortisol), and sex-steroid-binding protein. These proteins have a high affinity (Kd 10—9— 10 8 m) for their respective hormones. They buffer the concentration of free hormone and retard hormone degradation and excretion. The carrier proteins are distinguishable from the intracellular receptors for these hormones. 

Martin, M.E., Haourigui, M., and Pelissero, C. 1996. Interactions between phytoestrogens and human sex steroid binding protein. Life Sci. 58, 429-436. 

D9. Dechaud, H., Lejeune, H., Garoscio-Cholet, M., Mallein, R., andPugeat, M., Radioimmunoassay of testosterone not bound to sex-steroid-binding protein in plasma. Clin Chem. 35, 1609-1614 (1989). 

Tardivel-Lacombe, J. and Degrelle, H. (1991) Hormone-associated variation of the glycan microheterogeneity pattern of human sex steroid-binding protein (hSBP). Journal of Steroid Biochemistry and Molecular Biology, 39, 449-453. 

Phytoestrogens may modulate the activity of the human sex steroid binding protein and so influence the role of this protein in the delivery of hormonal information to sex steroid-dependent cells, as reported by Martin et al. [93] in research with NDGA, enterolactone and enterodiol. These phytoestrogens had different dose-dependent inhibitory effects on the steroid binding protein. 

P. H. Petra, P. R. Griffins, and J. R. Yates El, Complete enzymatic deglycosylation of native sex steroid-binding protein (SBP or SHBG) of human and rabbit plasma effect on the steroid binding activity. Protein Sci. 1, 902 (1992). 

Steroid hormones (e.g., cortisol and estrogen) are hydro-phobic and insoluble in water. These hormones circulate in plasma, reversibly bound to transport proteins (e.g., cortisol-binding globulin and sex-hormone binding globulin) with only a small fraction free or unbound available to exert physiological action.The half-life of steroid hormones is 30 to 90 minutes. Free steroid hormones, being hydrophobic, enter the cell by passive diffusion and bind with intracellular receptors either in the cytoplasm or the nucleus. ... 

Hammond, G.L. and W.P. Bocchinfuso. Sex hormone-binding globulin/androgen-binding protein steroidbinding and dimerization domains. J. Steroid Biochem. Mol. Biol. 53 543—552, 1995. 

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