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11-trifluoromethyl-phenyldiazirinyl neurosteroid analogues: potent general anesthetics and photolabeling reagents for GABAA receptors.
Chen ZW, Wang C, Krishnan K, Manion BD, Hastings R, Bracamontes J, Taylor A, Eaton MM, Zorumski CF, Steinbach JH, Akk G, Mennerick S, Covey DF, Evers AS.
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RATIONALE: While neurosteroids are well-described positive allosteric modulators of gamma-aminobutyric acid type A (GABAA) receptors, the binding sites that mediate these actions have not been definitively identified.
OBJECTIVES: This study was conducted to synthesize neurosteroid analogue photolabeling reagents that closely mimic the biological effects of endogenous neurosteroids and have photochemical properties that will facilitate their use as tools for identifying the binding sites for neurosteroids on GABAA receptors.
RESULTS: Two neurosteroid analogues containing a trifluromethyl-phenyldiazirine group linked to the steroid C11 position were synthesized. These reagents, CW12 and CW14, are analogues of allopregnanolone (5α-reduced steroid) and pregnanolone (5β-reduced steroid), respectively. Both reagents were shown to have favorable photochemical properties with efficient insertion into the C-H bonds of cyclohexane. They also effectively replicated the actions of allopregnanolone and pregnanolone on GABAA receptor functions: they potentiated GABA-induced currents in Xenopus laevis oocytes transfected with α1β2γ2L subunits, modulated [(35)S]t-butylbicyclophosphorothionate binding in rat brain membranes, and were effective anesthetics in Xenopus tadpoles. Studies using [(3)H]CW12 and [(3)H]CW14 showed that these reagents covalently label GABAA receptors in both rat brain membranes and in a transformed human embryonal kidney (TSA) cells expressing either α1 and β2 subunits or β3 subunits of the GABAA receptor. Photolabeling of rat brainGABAA receptors was shown to be both concentration-dependent and stereospecific.
CONCLUSIONS: CW12 and CW14 have the appropriate photochemical and pharmacological properties for use as photolabeling reagents to identify specific neurosteroid-binding sites on GABAA receptors.
Akk,
Kinetic and structural determinants for GABA-A receptor potentiation by neuroactive steroids.
2010, Pubmed
Akk,
Kinetic and structural determinants for GABA-A receptor potentiation by neuroactive steroids.
2010,
Pubmed Akk,
Neurosteroid access to the GABAA receptor.
2005,
Pubmed Akk,
Mutations of the GABA-A receptor alpha1 subunit M1 domain reveal unexpected complexity for modulation by neuroactive steroids.
2008,
Pubmed Akk,
Mechanisms of neurosteroid interactions with GABA(A) receptors.
2007,
Pubmed Akk,
Neuroactive steroids have multiple actions to potentiate GABAA receptors.
2004,
Pubmed Atkinson,
Action of some steroids on the centtral nervous system of the mouse. II. Pharmacology.
1965,
Pubmed Brunner,
New photolabeling and crosslinking methods.
1993,
Pubmed Brunner,
3-Trifluoromethyl-3-phenyldiazirine. A new carbene generating group for photolabeling reagents.
1980,
Pubmed Bureau,
GABAA receptor subtypes: ligand binding heterogeneity demonstrated by photoaffinity labeling and autoradiography.
1993,
Pubmed Chen,
Neurosteroid analog photolabeling of a site in the third transmembrane domain of the β3 subunit of the GABA(A) receptor.
2012,
Pubmed Chen,
A neurosteroid analogue photolabeling reagent labels the colchicine-binding site on tubulin: a mass spectrometric analysis.
2012,
Pubmed Chiara,
Specificity of intersubunit general anesthetic-binding sites in the transmembrane domain of the human α1β3γ2 γ-aminobutyric acid type A (GABAA) receptor.
2013,
Pubmed Chisari,
The sticky issue of neurosteroids and GABA(A) receptors.
2010,
Pubmed Covey,
Enantioselectivity of pregnanolone-induced gamma-aminobutyric acid(A) receptor modulation and anesthesia.
2000,
Pubmed Darbandi-Tonkabon,
Photoaffinity labeling with a neuroactive steroid analogue. 6-azi-pregnanolone labels voltage-dependent anion channel-1 in rat brain.
2003,
Pubmed
,
Xenbase Darbandi-Tonkabon,
Neuroactive steroid interactions with voltage-dependent anion channels: lack of relationship to GABA(A) receptor modulation and anesthesia.
2004,
Pubmed Evers,
A synthetic 18-norsteroid distinguishes between two neuroactive steroid binding sites on GABAA receptors.
2010,
Pubmed
,
Xenbase Franks,
General anaesthesia: from molecular targets to neuronal pathways of sleep and arousal.
2008,
Pubmed Gyermek,
Steroid anesthetics.
1975,
Pubmed Harrison,
Structure-activity relationships for steroid interaction with the gamma-aminobutyric acidA receptor complex.
1987,
Pubmed Hawkinson,
The neuroactive steroid 3 alpha-hydroxy-5 beta-pregnan-20-one is a two-component modulator of ligand binding to the GABAA receptor.
1994,
Pubmed Hosie,
Endogenous neurosteroids regulate GABAA receptors through two discrete transmembrane sites.
2006,
Pubmed Hosie,
Conserved site for neurosteroid modulation of GABA A receptors.
2009,
Pubmed Hosie,
Neurosteroid binding sites on GABA(A) receptors.
2007,
Pubmed Li,
Natural and enantiomeric etiocholanolone interact with distinct sites on the rat alpha1beta2gamma2L GABAA receptor.
2007,
Pubmed Li,
Hydrogen bonding between the 17beta-substituent of a neurosteroid and the GABA(A) receptor is not obligatory for channel potentiation.
2009,
Pubmed Pratt,
Identification of sites of incorporation in the nicotinic acetylcholine receptor of a photoactivatible general anesthetic.
2000,
Pubmed Shu,
Cyclodextrins sequester neuroactive steroids and differentiate mechanisms that rate limit steroid actions.
2007,
Pubmed
,
Xenbase Srinivasan,
Biphasic modulation of GABA(A) receptor binding by steroids suggests functional correlates.
1999,
Pubmed Wittig,
Blue native PAGE.
2006,
Pubmed Wittmer,
Enantioselectivity of steroid-induced gamma-aminobutyric acidA receptor modulation and anesthesia.
1996,
Pubmed
,
Xenbase Ziebell,
Identification of binding sites in the nicotinic acetylcholine receptor for [3H]azietomidate, a photoactivatable general anesthetic.
2004,
Pubmed
