SHBG Recombinant Rabbit mAb (SDT-1615-256)

Sex hormone-binding globulin (SHBG) is a 90 kDa homodimeric β-globulin produced primarily by hepatocytes but also by Sertoli cells, placenta and brain, whose single 373-residue polypeptide chain folds into a tandem steroid-binding/β-barrel domain that, after dimerization, creates two symmetrical hydrophobic pockets with high nanomolar affinity for 17β-hydroxysteroids such as testosterone and 17β-estradiol, thereby regulating the equilibrium between protein-bound (biologically inactive) and free (bioactive) sex steroids in blood, and whose hepatic synthesis is up-regulated by estrogens, thyroid hormones and anticonvulsants and down-regulated by androgens, progestins, insulin, obesity and inflammatory cytokines, so that circulating SHBG levels serve as a sensitive inverse index of insulin resistance and metabolic syndrome risk, while genetic polymorphisms and epigenetic modifications of the SHBG gene influence hormone-dependent phenotypes ranging from pubertal timing and bone density to polycystic ovary syndrome, androgen-deprivation therapy responses and hormone-sensitive cancers, making SHBG both a clinically useful biomarker and a potential therapeutic target for metabolic and endocrine disorders.