Sandbox Reserved 1646: Difference between revisions

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Conformational rearrangements of common microswitches<ref>DOI: 10.7554/eLife.28505</ref> are characteristically influenced by the unusual ligand recognition and the absence of the cytoplasmic C-terminal helix.  
Conformational rearrangements of common microswitches<ref>DOI: 10.7554/eLife.28505</ref> are characteristically influenced by the unusual ligand recognition and the absence of the cytoplasmic C-terminal helix.  
The transition of different GPCR conformation states is known to be mediated by water molecules by rearranging the conserved hydrophilic network formed by conserved amino acids in different helices<ref>DOI: 10.1073/pnas.1809251116</ref><ref>DOI: 10.1038/s41467-020-19109-w</ref>.
The transition of different GPCR conformation states is known to be mediated by water molecules by rearranging the conserved hydrophilic network formed by conserved amino acids in different helices<ref>DOI: 10.1073/pnas.1809251116</ref><ref>DOI: 10.1038/s41467-020-19109-w</ref>.
==Gonadotropin releasing hormone==
===Hormone===
GnRH is a decapeptide that was isolated and characterized by the groups of A V Schally and R C L Guillemin, the 1977 Nobel laureates.
GnRH is the pivotal hypothalamic hormone regulating reproduction. Over 20 forms of the decapeptide have been identified in which the NH2- and COOH-terminal sequences, which are essential for receptor binding and activation, are conserved.
In most vertebrates, there are at least two, and usually three, forms of GnRH. In mammals, there are two forms, GnRH I which regulates gonadotropin, and GnRH II which appears to be a neuromodulator and stimulates sexual behavior.
===Antagonist===
Like GnRH, peptide antagonists of the GnRH receptor are decapeptides, but with 50–70% of amino acids substituted, and they exhibit classical competitive antagonism ;
Blockade of GnRH effects may be wanted for a variety of reasons—eg, to prevent untimely luteinization during assisted reproduction or in the treatment of sex-hormone-dependent disorders
Unlike the agonists, GnRH antagonists do not induce an initial stimulation of gonadotropin release but cause an immediate and rapid, reversible suppression of gonadotropin secretion. The principal mechanism of action of GnRH antagonists is competitive receptor occupancy of GnRH-r<ref>DOI: 10.1016/S0140-6736(01)06797-6</ref>.


== Disease ==
== Disease ==