hFSH-β-(33-53)

hFSH-β-(33-53) is a polypeptide corresponding to residues 33-53 of hFSH-β, and also a follicle-stimulating hormone ( FSH ) antagonist. hFSH-β-(33-53) stimulates basal estradiol synthesis in cells. hFSH-β-(33-53) prolongs vaginal estrus in mice with normal estrous cycles ^{[1] [2]}.

In Vivo, hFSH-β-(33-53) (4 mg/g body weight; i.p.; single injection) induces prolonged vaginal estrus in 50% of normally cycling adult female Swiss Webster mice^[2].

In Vitro, hFSH-β-(33-53) is a moderate-potency antagonist of hFSH; after radioiodination and alkylation modification, this peptide has a Kd of 5.5×10-5 M for the hFSH receptor^[1]. hFSH-β-(33-53) inhibits the binding of [125I]hFSH to FSH receptors in calf testicular membranes^[2]. hFSH-β-(33-53) regulates estradiol biosynthesis in primary rat Sertoli cells under basal conditions and/or FSH stimulation^[2].

References:
[1]. Agris PF, et al. Solution structure of a synthetic peptide corresponding to a receptor binding region of FSH (hFSH-beta 33-53). J Protein Chem. 1992;11(5):495-507.
[2]. Grasso P, et al. Cysteine residues in a synthetic peptide corresponding to human follicle-stimulating hormone beta-subunit receptor-binding domain 81-95 [hFSH-beta-(81-95)] modulate the in vivo effects of hFSH-beta-(81-95) on the mouse estrous cycle. Regul Pept. 1999;81(1-3):67-71.