Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-45196
J Med Chem 2012 Feb 09;553:1334-45. doi: 10.1021/jm2014925.
Show Gene links Show Anatomy links

Neurosteroid analogues. 17. Inverted binding orientations of androsterone enantiomers at the steroid potentiation site on γ-aminobutyric acid type A receptors.

Krishnan K , Manion BD , Taylor A , Bracamontes J , Steinbach JH , Reichert DE , Evers AS , Zorumski CF , Mennerick S , Covey DF .


???displayArticle.abstract???
The enantiomer pair androsterone and ent-androsterone are positive allosteric modulators of γ-aminobutyric acid (GABA) type A receptors. Each enantiomer was shown to bind at the same receptor site. Binding orientations of the enantiomers at this site were deduced using enantiomer pairs containing OBn substituents at either C-7 or C-11. 11β-OBn-substituted steroids and 7α-OBn-substituted ent-steroids potently displace [(35)S]-tert-butylbicyclophosphorothionate, augment GABA currents, and anesthetize tadpoles. In contrast, 7β-OBn-substituted steroids and 11α-OBn-substituted ent-steroids have diminished actions. The results suggest that the binding orientations of the active analogues are inverted relative to each other with the 7α- and 11β-substituents similarly located on the edges of the molecules not in contact with the receptor surface. Analogue potentiation of the GABA current was abrogated by an α(1) subunit Q241L mutation, indicating that the active analogues act at the same sites in α(1)β(2)γ(2L) receptors previously associated with positive neurosteroid modulation.

???displayArticle.pubmedLink??? 22191644
???displayArticle.pmcLink??? PMC3276733
???displayArticle.link??? J Med Chem
???displayArticle.grants??? [+]

Species referenced: Xenopus laevis
Genes referenced: tert

References [+] :
Akk, Mutations of the GABA-A receptor alpha1 subunit M1 domain reveal unexpected complexity for modulation by neuroactive steroids. 2008, Pubmed