gonadotropin-inhibitory hormone

Description

Gonadotropin-inhibitory hormone, a hypothalamic neuropeptide inhibiting gonadotropin secretion. GnIH inhibits sociosexual and aggressive behavior. It has an LPXRFamide (X?L or Q) sequence at its C-terminal.

Industrial uses

The endogenous inhibitor of gonadotropin secretion, GnIH, has therapeutic potential in the treatment of gonadotropins or steroid hormone-dependent diseases, such as precocious puberty, endometriosis, uterine fibroids, benign prostatic hyperplasia, and prostatic and breast cancers. Human GnIH may also have potential as a novel contraceptive.

Biological Activity

Human GnIH1 (RFRP-1): Mr 1,429, pI 10.55. Freely soluble in water. Human GnIH1 (RFRP-1) dissolved in water at 10^-3 M is stable for more than a year at - 20°C. Human GnIH2 (RFRP-3): Mr 969, pI 10.55. Freely soluble in water. Human GnIH2 (RFRP-3) dissolved in water at 10^{- 3} M is stable for more than a year at - 20°C.

Structure and conformation

Most GnIH peptides have the LPXRFamide (X?L or Q) motif at their C-termini . Although the N-terminal sequences are less conserved across vertebrate species, it has been observed that many identified endogenous GnIH peptides start from serine at the N-terminal (macaque RFRP-3, bovine RFRP-1, hamster RFRP-1, quail GnIH, quail GnIH-RP-2, starling GnIH, zebra finch GnIH, frog GRP, frog GRP-RP-1, newt LPXRFa-1, newt LPXRFa-3, goldfish LPXRFa-3, lamprey LPXRFa-1a, and lamprey LPXRFa-2). Other GnIH peptides start from alanine (bovine RFRP-3, rat RFRP-3, frog GRP-RP-3, newt LPXRFa-4, and lamprey LPXRFa-1b), methionine (human RFRP-1, newt LPXRFa-2), valine (human RFRP-3), threonine (hamster RFRP-3), and tyrosine (frog GRP-RP-2) at their N-termini.