|Androgen-binding protein, Sex hormone-binding globulin|
|Locus||Chr. 17 p13-p12|
Androgen-binding protein (ABP) is a glycoprotein (beta-globulin) produced by the Sertoli cells in the seminiferous tubules of the testis that binds specifically to testosterone (T), dihydrotestosterone (DHT), and 17-beta-estradiol.
Because ABP binds to T and DHT, these hormones are made less lipophilic and become concentrated within the luminal fluid of the seminiferous tubules. The higher levels of these hormones enable spermatogenesis in the seminiferous tubules and sperm maturation in the epididymis.
ABP has the same amino acid sequence as sex hormone-binding globulin (SHBG); the difference is the site of production and the addition of different sugar moieties. ABP contains 403 amino acids, resulting in a molecular weight of 44,533. Its gene is located on chromosome 17.
ABP may also be secreted in other organs; for instance, mice produce a salivary ABP.
- Sex hormone-binding globulin (SHBG)
- Bardin CW, Musto N, Gunsalus G, Kotite N, Cheng SL, Larrea F, Becker R (1981). "Extracellular androgen binding proteins". Annual Review of Physiology. 43: 189–98. doi:10.1146/annurev.ph.43.030181.001201. PMID 7011179.
- Hansson V, Weddington SC, French FS, McLean W, Smith A, Nayfeh SN, Ritzén EM, Hagenäs L (September 1976). "Secretion and role of androgen-binding proteins in the testis and epididymis". Journal of Reproduction and Fertility. Supplement (24 suppl): 17–33. PMID 1069850.
- Androgen-Binding+Protein at the US National Library of Medicine Medical Subject Headings (MeSH)
- Ensembl Gene ref Protein ref