General Anesthetic Sites on Ligand-Gated Ion Channels

Summary

Principal Investigator: Keith W Miller
Abstract: Some 25 million patients are given general anesthesia each year in the USA using agents with very low therapeutic indices. The molecular mechanisms of general anesthesia remain unknown, hampering the design of improved agents. General anesthetics act on a superfamily of ligand gated channels which include inhibitory anion channels gated by GABA and glycine, and excitatory cation channels gated by serotonin and acetylcholine. This PPG focuses on the ability of general anesthetics to enhance the activity of the inhibitory GABAA receptor (GABAAR) and to inhibit, and in some cases enhance, the excitatory neuronal nicotinic acetylcholine (nAcChoR) and serotonin (5HT3R) receptors. The overall hypothesis is that the various actions of general anesthetics are mediated by a number of binding sites on these receptors, that their location and affinity varies with the anesthetic's structure and the receptor's conformation. The overall aims of the PPG are to: (i) locate the anesthetic binding sites on the GABAA, nAcChoR and 5-HT3 receptors using anesthetic photolabels, and (ii) define how their occupancy allosterically modulates receptor function using rapid perfusion patch clamp techniques. Project 1 will locate sites of etomidate, propofol and barbiturate photolabels on equilibrium states of GABAAR and nAcChoRs. Project 2 focuses on the interaction of anesthetics with receptors during gating using in parallel electrophysiological and time-resolved photolabeling. Project 3 will define in detail the kinetic mechanisms of anesthetic action on GABAARS using rapid perfusion patch clamp techniques in wild type and mutated receptors, incorporating the photolabeling results to guide mutagenesis and interpretation. A Synthetic Chemistry Core develops and supplies novel photoaffinity general anesthetics. A Protein Chemistry Core locates the sites of photoincorporation and develops homology models of receptors to guide mutagenesis work. A Protein Production Core supplies large quantities of heterologously expressed, purified and reconstituted neuronal receptors for photolabeling.
Funding Period: 1998-12-01 - 2014-08-31
more information: NIH RePORT

Top Publications

  1. pmc Identifying barbiturate binding sites in a nicotinic acetylcholine receptor with [3H]allyl m-trifluoromethyldiazirine mephobarbital, a photoreactive barbiturate
    Ayman K Hamouda
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts A K H, D C C, J B C Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts D S S and Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois P Y S, K S B
    Mol Pharmacol 85:735-46. 2014
  2. pmc Bupropion binds to two sites in the Torpedo nicotinic acetylcholine receptor transmembrane domain: a photoaffinity labeling study with the bupropion analogue [(125)I]-SADU-3-72
    Akash Pandhare
    Department of Pharmacology and Neuroscience and the Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, United States
    Biochemistry 51:2425-35. 2012
  3. pmc The location and nature of general anesthetic binding sites on the active conformation of firefly luciferase; a time resolved photolabeling study
    Sivananthaperumal Shanmugasundararaj
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts, United States of America
    PLoS ONE 7:e29854. 2012
  4. pmc Mapping general anesthetic binding site(s) in human α1β3 γ-aminobutyric acid type A receptors with [³H]TDBzl-etomidate, a photoreactive etomidate analogue
    David C Chiara
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
    Biochemistry 51:836-47. 2012
  5. pmc An allosteric coagonist model for propofol effects on α1β2γ2L γ-aminobutyric acid type A receptors
    Dirk Ruesch
    Department of Anesthesia and Intensive Care, University Hospital Giessen Marburg, Marburg, Germany
    Anesthesiology 116:47-55. 2012
  6. pmc Mutations in the GABAA receptor that mimic the allosteric ligand etomidate
    Stuart A Forman
    Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
    Methods Mol Biol 796:317-33. 2012
  7. pmc p-(4-Azipentyl)propofol: a potent photoreactive general anesthetic derivative of propofol
    Deirdre S Stewart
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
    J Med Chem 54:8124-35. 2011
  8. pmc Multiple transmembrane binding sites for p-trifluoromethyldiazirinyl-etomidate, a photoreactive Torpedo nicotinic acetylcholine receptor allosteric inhibitor
    Ayman K Hamouda
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    J Biol Chem 286:20466-77. 2011
  9. pmc Clinical and molecular pharmacology of etomidate
    Stuart A Forman
    Harvard Medical School, Boston, Massachusetts, USA
    Anesthesiology 114:695-707. 2011
  10. pmc Anesthetic sites and allosteric mechanisms of action on Cys-loop ligand-gated ion channels
    Stuart A Forman
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Jackson 444, Boston, MA 02114, USA
    Can J Anaesth 58:191-205. 2011

Research Grants

Detail Information

Publications62

  1. pmc Identifying barbiturate binding sites in a nicotinic acetylcholine receptor with [3H]allyl m-trifluoromethyldiazirine mephobarbital, a photoreactive barbiturate
    Ayman K Hamouda
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts A K H, D C C, J B C Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts D S S and Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois P Y S, K S B
    Mol Pharmacol 85:735-46. 2014
    ....
  2. pmc Bupropion binds to two sites in the Torpedo nicotinic acetylcholine receptor transmembrane domain: a photoaffinity labeling study with the bupropion analogue [(125)I]-SADU-3-72
    Akash Pandhare
    Department of Pharmacology and Neuroscience and the Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, United States
    Biochemistry 51:2425-35. 2012
    ....
  3. pmc The location and nature of general anesthetic binding sites on the active conformation of firefly luciferase; a time resolved photolabeling study
    Sivananthaperumal Shanmugasundararaj
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts, United States of America
    PLoS ONE 7:e29854. 2012
    ..Second, a competitive one, in which anesthetics bind isosterically with luciferin. This work provides structural evidence that supports the competitive and allosteric actions previously characterized by kinetic studies...
  4. pmc Mapping general anesthetic binding site(s) in human α1β3 γ-aminobutyric acid type A receptors with [³H]TDBzl-etomidate, a photoreactive etomidate analogue
    David C Chiara
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
    Biochemistry 51:836-47. 2012
    ..Etomidate-inhibitable photolabeling of β3Met-227 in βM1 by [³H]TDBzl-etomidate and [³H]azietomidate also provides evidence of a homologous etomidate binding site at the β3-β3 subunit interface in the α1β3 GABA(A)R...
  5. pmc An allosteric coagonist model for propofol effects on α1β2γ2L γ-aminobutyric acid type A receptors
    Dirk Ruesch
    Department of Anesthesia and Intensive Care, University Hospital Giessen Marburg, Marburg, Germany
    Anesthesiology 116:47-55. 2012
    ..It is unknown if the propofol binding site(s) on GABA(A) receptors that modulate agonist-induced activity also mediate direct activation...
  6. pmc Mutations in the GABAA receptor that mimic the allosteric ligand etomidate
    Stuart A Forman
    Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
    Methods Mol Biol 796:317-33. 2012
    ..Furthermore, these mutations reduce receptor modulation by etomidate. Both of these observations support the hypothesis that these methionine residues form part of the etomidate binding pocket...
  7. pmc p-(4-Azipentyl)propofol: a potent photoreactive general anesthetic derivative of propofol
    Deirdre S Stewart
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
    J Med Chem 54:8124-35. 2011
    ..Thus, p-4-AziC5-Pro is a functional general anesthetic that both modulates and photoincorporates into Cys-loop ligand-gated ion channels, making it an excellent candidate for use in identifying propofol binding sites...
  8. pmc Multiple transmembrane binding sites for p-trifluoromethyldiazirinyl-etomidate, a photoreactive Torpedo nicotinic acetylcholine receptor allosteric inhibitor
    Ayman K Hamouda
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    J Biol Chem 286:20466-77. 2011
    ..These results also suggest that the γ-α subunit interface is a binding site for Torpedo nAChR negative allosteric modulators (TFD-etomidate) and for positive modulators (TDBzl-etomidate)...
  9. pmc Clinical and molecular pharmacology of etomidate
    Stuart A Forman
    Harvard Medical School, Boston, Massachusetts, USA
    Anesthesiology 114:695-707. 2011
    ..Based on this deepening understanding of molecular targets and actions, new etomidate derivatives are being investigated as potentially improved sedative-hypnotics or for use as highly selective inhibitors of adrenal steroid synthesis...
  10. pmc Anesthetic sites and allosteric mechanisms of action on Cys-loop ligand-gated ion channels
    Stuart A Forman
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Jackson 444, Boston, MA 02114, USA
    Can J Anaesth 58:191-205. 2011
    ....
  11. pmc Molecular approaches to improving general anesthetics
    Stuart A Forman
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Jackson 4, MGH, 55 Fruit Street, Boston, MA 02114, USA
    Anesthesiol Clin 28:761-71. 2010
    ..The goal of this review is to highlight these important developments and describe translational research on new general anesthetics with the potential to improve and reshape clinical care...
  12. pmc p-Trifluoromethyldiazirinyl-etomidate: a potent photoreactive general anesthetic derivative of etomidate that is selective for ligand-gated cationic ion channels
    S Shaukat Husain
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, Massachusetts 02114, USA
    J Med Chem 53:6432-44. 2010
    ..TFD-etomidate's novel pharmacology is unlike that of etomidate derivatives with photoactivable groups in the ester position, which behave like etomidate, suggesting that it will further enhance our understanding of anesthetic mechanisms...
  13. pmc High-level expression and purification of Cys-loop ligand-gated ion channels in a tetracycline-inducible stable mammalian cell line: GABAA and serotonin receptors
    Zuzana Dostalova
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
    Protein Sci 19:1728-38. 2010
    ....
  14. pmc Ethanol stabilizes the open state of single 5-hydroxytryptamine(3A)(QDA) receptors
    Paula L Feinberg-Zadek
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
    J Pharmacol Exp Ther 333:896-902. 2010
    ..Furthermore, the 5-HT(3A)(QDA) receptor appears to be suitable for pharmacological studies of 5-HT(3A) receptor modulation at a single-channel level...
  15. pmc Two etomidate sites in α1β2γ2 γ-aminobutyric acid type A receptors contribute equally and noncooperatively to modulation of channel gating
    Grigori Guitchounts
    Department of Neurobiology, Boston University, Boston, MA, USA
    Anesthesiology 116:1235-44. 2012
    ..Evidence supports the presence of two etomidate sites per GABA(A) receptor, and current models assume that each site contributes equally and noncooperatively to drug effects. These assumptions remain untested...
  16. pmc Monod-Wyman-Changeux allosteric mechanisms of action and the pharmacology of etomidate
    Stuart A Forman
    Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
    Curr Opin Anaesthesiol 25:411-8. 2012
    ..However, the mathematical formalism of these mechanisms makes them difficult to comprehend...
  17. pmc Allyl m-trifluoromethyldiazirine mephobarbital: an unusually potent enantioselective and photoreactive barbiturate general anesthetic
    Pavel Y Savechenkov
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, MA 02114, USA
    J Med Chem 55:6554-65. 2012
    ..These results indicate R-(-)-14 is a functional general anesthetic that is well-suited for identifying barbiturate binding sites on Cys-loop receptors...
  18. pmc Photoaffinity labeling the propofol binding site in GLIC
    David C Chiara
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, United States
    Biochemistry 53:135-42. 2014
    ..Thus, for GLIC in solution, propofol and AziPm bind competitively to a site in proximity to these residues, which, in the GLIC crystal structure, are in contact with the propofol bound in the intrasubunit pocket. ..
  19. pmc Human α1β3γ2L gamma-aminobutyric acid type A receptors: High-level production and purification in a functional state
    Zuzana Dostalova
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, 02114 Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, 02115
    Protein Sci 23:157-66. 2014
    ..The composition of the purified, reconstituted receptors was confirmed by ligand binding, Western blot, and proteomics. Allosteric interactions between etomidate and [(3)H]muscimol binding were maintained in the purified state...
  20. pmc Etomidate produces similar allosteric modulation in α1β3δ and α1β3γ2L GABA(A) receptors
    H J Feng
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
    Br J Pharmacol 171:789-98. 2014
    ....
  21. pmc Structural models of ligand-gated ion channels: sites of action for anesthetics and ethanol
    Richard W Olsen
    Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California
    Alcohol Clin Exp Res 38:595-603. 2014
    ..Recent structural information from crystallized procaryotic (ELIC and GLIC) and eukaryotic (GluCl) LGICs allows refinement of the structural models including evaluation of possible sites of EtOH action. ..
  22. pmc Cysteine substitutions define etomidate binding and gating linkages in the α-M1 domain of γ-aminobutyric acid type A (GABAA) receptors
    Deirdre S Stewart
    From the Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
    J Biol Chem 288:30373-86. 2013
    ..Our results are consistent with in silico docking calculations in a homology model that orient the long axis of etomidate approximately orthogonal to the transmembrane axis. ..
  23. pmc Specificity of intersubunit general anesthetic-binding sites in the transmembrane domain of the human α1β3γ2 γ-aminobutyric acid type A (GABAA) receptor
    David C Chiara
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    J Biol Chem 288:19343-57. 2013
    ..We hypothesize that binding at any of these homologous intersubunit sites is sufficient for anesthetic action and that this explains to some degree the puzzling structural heterogeneity of anesthetics. ..
  24. pmc State-dependent etomidate occupancy of its allosteric agonist sites measured in a cysteine-substituted GABAA receptor
    Deirdre S Stewart
    Department of Anesthesia Critical Care and Pain Medicine, Beecher Mallinckrodt Research Laboratories, and Department of Anesthesia Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
    Mol Pharmacol 83:1200-8. 2013
    ..Our results support MWC models as valid frameworks for understanding the agonism, coagonism, and modulation of ligand-gated ion channels...
  25. pmc The pyrrole etomidate analog carboetomidate potently inhibits human 5-HT3A receptor function: comparisons with etomidate and potential implications for emetogenesis
    Rooma Desai
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114 2621, USA
    Anesth Analg 116:573-9. 2013
    ..In the current studies, we investigated and compared modulation of 5-HT(3A) receptors by carboetomidate and etomidate...
  26. pmc Physostigmine and galanthamine bind in the presence of agonist at the canonical and noncanonical subunit interfaces of a nicotinic acetylcholine receptor
    Ayman K Hamouda
    Department of Neurobiology and PhD Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02115, USA
    J Neurosci 33:485-94. 2013
    ....
  27. pmc Identification of propofol binding sites in a nicotinic acetylcholine receptor with a photoreactive propofol analog
    Selwyn S Jayakar
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    J Biol Chem 288:6178-89. 2013
    ..These results identify for the first time a single intrasubunit propofol binding site in the nAChR transmembrane domain and suggest that this is the functionally relevant inhibitory binding site...
  28. pmc Ethanol promotes clathrin adaptor-mediated endocytosis via the intracellular domain of δ-containing GABAA receptors
    Claudia Gonzalez
    Department of Molecular and Medical Pharmacology, Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095 1735, USA
    J Neurosci 32:17874-81. 2012
    ....
  29. pmc Numerous classes of general anesthetics inhibit etomidate binding to gamma-aminobutyric acid type A (GABAA) receptors
    Guo dong Li
    Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, USA
    J Biol Chem 285:8615-20. 2010
    ....
  30. pmc Conformational changes in the nicotinic acetylcholine receptor during gating and desensitization
    Innocent H Yamodo
    Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
    Biochemistry 49:156-65. 2010
    ....
  31. ncbi Differential effects of serotonin and dopamine on human 5-HT3A receptor kinetics: interpretation within an allosteric kinetic model
    Ken Solt
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
    J Neurosci 27:13151-60. 2007
    ....
  32. pmc Identifying the lipid-protein interface of the alpha4beta2 neuronal nicotinic acetylcholine receptor: hydrophobic photolabeling studies with 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine
    Ayman K Hamouda
    Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
    Biochemistry 46:13837-46. 2007
    ....
  33. pmc The conformation of acetylcholine at its target site in the membrane-embedded nicotinic acetylcholine receptor
    P T F Williamson
    Physical Chemistry, ETH Zurich, Wolfgang Pauli Strasse 10, CH 8093 Zurich, Switzerland
    Proc Natl Acad Sci U S A 104:18031-6. 2007
    ..The observed >C O chemical shift is consistent with H bonding to the nicotinic acetylcholine receptor residues gammaY116 and deltaT119 that are homologous to L112 in the soluble acetylcholine-binding protein...
  34. ncbi Volatile aromatic anesthetics variably impact human gamma-aminobutyric acid type A receptor function
    Elizabeth W Kelly
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
    Anesth Analg 105:1287-92, table of contents. 2007
    ..In this study, we sought to assess the potential role that GABA(A) receptors play in mediating the behavioral actions of volatile aromatic anesthetics...
  35. ncbi Photoactivated 3-azioctanol irreversibly desensitizes muscle nicotinic ACh receptors via interactions at alphaE262
    Stuart A Forman
    Department of Anesthesia and Critical Care, Jackson 4, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
    Biochemistry 46:11911-8. 2007
    ..Occupation of this pocket by hydrophobic molecules stabilizes a desensitized state by slowing resensitization...
  36. ncbi [3H]Benzophenone photolabeling identifies state-dependent changes in nicotinic acetylcholine receptor structure
    Galo Garcia
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    Biochemistry 46:10296-307. 2007
    ..These results provide a further definition of the regions in the nAChR transmembrane domain that differ in structure between the closed and desensitized states...
  37. pmc Inhibition of human 5-HT(3A) and 5-HT(3AB) receptors by etomidate, propofol and pentobarbital
    Dirk Rüsch
    Department of Anaesthesia and Critical Care, University Hospital Giessen Marburg GmbH, Marburg Campus, Baldingerstrasse, 35033 Marburg, Germany
    Eur J Pharmacol 573:60-4. 2007
    ....
  38. ncbi A proteomic study of sodium/D-glucose cotransporter 1 (SGLT1): topology of loop 13 and coverage of other functionally important domains
    Azad Kumar
    Max Planck Institute of Molecular Physiology, Otto Hahn Str 11, Dortmund 44227, Germany
    Biochim Biophys Acta 1774:968-74. 2007
    ..These studies demonstrate that proteomic analysis combined with mass spectrometry is a useful tool to characterize regions of SGLT1 that are important for its function and regulation...
  39. ncbi Subunit-dependent modulation of the 5-hydroxytryptamine type 3 receptor open-close equilibrium by n-alcohols
    Dirk Rüsch
    Department of Anesthesia and Critical Care, University Hospital Giessen Marburg GmbH, Marburg Campus, Baldingerstrasse, 35033 Marburg, Germany
    J Pharmacol Exp Ther 321:1069-74. 2007
    ..We conclude that the presence of the 5-HT(3B) subunit in 5-HT(3AB) receptors significantly reduces the enhancement of gating efficacy by small alcohols without altering the inhibitory actions of large alcohols...
  40. ncbi Identification of a GABAA receptor anesthetic binding site at subunit interfaces by photolabeling with an etomidate analog
    Guo dong Li
    Department of Molecular and Medical Pharmacology, Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA
    J Neurosci 26:11599-605. 2006
    ....
  41. ncbi Mapping the structural requirements for nicotinic acetylcholine receptor activation by using tethered alkyltrimethylammonium agonists and antagonists
    Deirdre S Stewart
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    Biochemistry 45:10641-53. 2006
    ..The inability of thiocholine to activate from alphaY93C, which is not predicted by the model, is discussed in terms of the structure of the nAChR in the closed state...
  42. ncbi Synthesis of trifluoromethylaryl diazirine and benzophenone derivatives of etomidate that are potent general anesthetics and effective photolabels for probing sites on ligand-gated ion channels
    S Shaukat Husain
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts 02114 USA
    J Med Chem 49:4818-25. 2006
    ..Thus, they have the necessary pharmacological and photochemical properties to be useful in identifying the site of etomidate-induced anesthesia...
  43. pmc Kinetics of anesthetic-induced conformational transitions in a four-alpha-helix bundle protein
    Ken Solt
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, 55 Fruit Street, Clinics Building 3, Boston, Massachusetts 02114, USA
    Biochemistry 45:1435-41. 2006
    ....
  44. pmc Photo-activated azi-etomidate, a general anesthetic photolabel, irreversibly enhances gating and desensitization of gamma-aminobutyric acid type A receptors
    Huijun Zhong
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
    Anesthesiology 108:103-12. 2008
    ..The authors examine the irreversible effects of azi-etomidate photo-modification on functional GABA(A) receptors in cell membranes...
  45. pmc Identification of binding sites in the nicotinic acetylcholine receptor for TDBzl-etomidate, a photoreactive positive allosteric effector
    Selvanayagam Nirthanan
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    J Biol Chem 283:22051-62. 2008
    ....
  46. pmc General anesthetics and molecular mechanisms of unconsciousness
    Stuart A Forman
    Department of Anaesthesia, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
    Int Anesthesiol Clin 46:43-53. 2008
  47. pmc Inhibition of human alpha4beta2 neuronal nicotinic acetylcholine receptors by volatile aromatic anesthetics depends on drug hydrophobicity
    Ken Solt
    Department of Anaesthesia, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
    Anesth Analg 110:455-60. 2010
    ..In this study, we tested the hypothesis that aromatic anesthetics reversibly inhibit alpha(4)beta(2) neuronal nACh receptor function and sought to determine the structural correlates of receptor inhibition...
  48. pmc [(3)H]chlorpromazine photolabeling of the torpedo nicotinic acetylcholine receptor identifies two state-dependent binding sites in the ion channel
    David C Chiara
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    Biochemistry 48:10066-77. 2009
    ....
  49. pmc Gamma-amino butyric acid type A receptor mutations at beta2N265 alter etomidate efficacy while preserving basal and agonist-dependent activity
    Rooma Desai
    Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, MA, USA
    Anesthesiology 111:774-84. 2009
    ..Mutations at beta residue 265 (Ser in beta1; Asn in beta2 or beta3) profoundly affect etomidate sensitivity. Whether these mutations alter etomidate binding remains uncertain...
  50. pmc Hydrophobic photolabeling studies identify the lipid-protein interface of the 5-HT3A receptor
    Mitesh Sanghvi
    Department of Pharmacology and Neuroscience and Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
    Biochemistry 48:9278-86. 2009
    ..These results provide a first definition of the surface of the 5-HT(3A)R M4 helix that is exposed to lipid and establish that this surface is equivalent to the surface exposed to lipid in the Torpedo nAChR...
  51. pmc Methoxycarbonyl-etomidate: a novel rapidly metabolized and ultra-short-acting etomidate analogue that does not produce prolonged adrenocortical suppression
    Joseph F Cotten
    Harvard Medical School, Boston, Massachusetts, USA
    Anesthesiology 111:240-9. 2009
    ....
  52. pmc [(3)H]Epibatidine photolabels non-equivalent amino acids in the agonist binding site of Torpedo and alpha4beta2 nicotinic acetylcholine receptors
    Shouryadeep Srivastava
    Department of Pharmacology and Neuroscience and the Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
    J Biol Chem 284:24939-47. 2009
    ....
  53. pmc Neurosteroids allosterically modulate binding of the anesthetic etomidate to gamma-aminobutyric acid type A receptors
    Guo dong Li
    Department of Molecular and Medical Pharmacology, Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
    J Biol Chem 284:11771-5. 2009
    ..M., Wilkins, M. E., da Silva, H. M., and Smart, T. G. (2006) Nature 444, 486-489) are located at the subunit interface defined by our etomidate site model...
  54. pmc Time-resolved photolabeling of the nicotinic acetylcholine receptor by [3H]azietomidate, an open-state inhibitor
    David C Chiara
    Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
    Mol Pharmacol 75:1084-95. 2009
    ....
  55. pmc A comparison of the molecular bases for N-methyl-D-aspartate-receptor inhibition versus immobilizing activities of volatile aromatic anesthetics
    Jason C Sewell
    Nuffield Department of Anesthetics, University of Oxford, The John Radcliffe Hospital, Headington, Oxford, UK
    Anesth Analg 108:168-75. 2009
    ..We sought to characterize the molecular basis of NMDA receptor inhibition using comparative molecular field analysis (CoMFA), and compare the results to those from an equivalent model for immobilizing activity...
  56. pmc Probing the structure of the affinity-purified and lipid-reconstituted torpedo nicotinic acetylcholine receptor
    Ayman K Hamouda
    Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
    Biochemistry 47:12787-94. 2008
    ....
  57. pmc Tryptophan mutations at azi-etomidate photo-incorporation sites on alpha1 or beta2 subunits enhance GABAA receptor gating and reduce etomidate modulation
    Deirdre Stewart
    Beecher Mallincrodt Labs, Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
    Mol Pharmacol 74:1687-95. 2008
    ..Furthermore, quantitative mechanistic analysis demonstrated that wild-type and mutant results are consistent with the presence of only one class of etomidate sites mediating both agonist potentiation and direct activation...
  58. pmc International Union of Pharmacology. LXX. Subtypes of gamma-aminobutyric acid(A) receptors: classification on the basis of subunit composition, pharmacology, and function. Update
    Richard W Olsen
    Department of Molecular and Medical Pharmacology, Geffen School of Medicine at UCLA, Room CHS 23 120, 650 Young Drive South, Los Angeles, CA 90095 1735, USA
    Pharmacol Rev 60:243-60. 2008
    ..The list is divided into three categories of native receptor subtypes: "identified," "existence with high probability," and "tentative."..
  59. pmc A nomenclature for ligand-gated ion channels
    Graham L Collingridge
    MRC Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol, Bristol BS8 1TD, UK
    Neuropharmacology 56:2-5. 2009
    ..The aim of this short article is to summarize the progress being made by the nomenclature committee of IUPHAR (NC-IUPHAR) in formulating recommendations that attempt to address these issues...
  60. pmc Cholesterol interacts with transmembrane alpha-helices M1, M3, and M4 of the Torpedo nicotinic acetylcholine receptor: photolabeling studies using [3H]Azicholesterol
    Ayman K Hamouda
    Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
    Biochemistry 45:976-86. 2006
    ..These results establish that cholesterol likely interacts with the M4, M3, and M1 segments of each subunit, and therefore, the cholesterol binding domain fully overlaps the lipid-protein interface of the nAChR...

Research Grants30

  1. CENTER FOR GASTROINTESTINAL BIOLOGY AND DISEASE
    Robert S Sandler; Fiscal Year: 2013
    ..Through all of its activities, the Center improves communication, promotes collaboration, develops careers and generally enriches the intellectual climate for digestive disease research. ..
  2. DIETARY AND HORMONAL DETERMINANTS OF CANCER IN WOMEN
    Meir Stampfer; Fiscal Year: 2013
    ..abstract_text> ..
  3. PHENIX: new methods for automation in macromolecular crystallography
    PAUL DAVID ADAMS; Fiscal Year: 2013
    ..Program Director/Principal Investigator (Last, First, Middle): Adams, Paul D. Use only if additional space is needed to list additional ..
  4. Baylor Intellectual and Developmental Disabilities Research Center
    Huda Y Zoghbi; Fiscal Year: 2013
    ..abstract_text> ..
  5. Molecular motors in cell biology
    Yale E Goldman; Fiscal Year: 2013
    ..We anticipate that the proposed work will take us significantly further toward our goal of understanding motility in the normal and pathological function of cells. ..
  6. Cardiac Myosin Binding Protein-C: Structure, Function, and Regulation
    David M Warshaw; Fiscal Year: 2013
    ..abstract_text> ..
  7. Signaling of Endothelial Permeability and Lung Vascular Injury
    Asrar B Malik; Fiscal Year: 2013
    ..Moreover the depth of understanding to be gained of the signaling pathways mediating the increase in lung vascular permeability will provide novel insights into the mechanisms of protein-rich pulmonary edema and ARDS. ..
  8. Re-wiring of gene expression in the meiotic state
    ALLEN BRUCE FUTCHER; Fiscal Year: 2013
    ..Dr. Leatherwood) The research Projects will be supported by a Microarray Core Facility, which will play a crucial role in all four projects. ..
  9. DGAP: Developmental Genome Anatomy Project
    CYNTHIA CASSON MORTON; Fiscal Year: 2013
    ....
  10. Protein Dynamics in Enzymatic Catalysis
    Robert Callender; Fiscal Year: 2013
    ..The Equipment Core (Core A) supports the specialized comprehensive suite of instrumentation for the Program. The Administrative Core (Core B) administers the Program Project. ..
  11. UNMC EPPLEY CANCER CENTER SUPPORT GRANT
    Kenneth H Cowan; Fiscal Year: 2013
    ....