1
|
Saberfard D, Sarchahi AA, Mehrjerdi HK. Effect of medetomidine, midazolam, ketamine, propofol and isoflurane on spinal reflexes in healthy dogs. Vet Med Sci 2022; 8:2351-2359. [DOI: 10.1002/vms3.938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Donya Saberfard
- Faculty of Veterinary Medicine Ferdowsi University of Mashhad Mashhad Iran
| | - Ali Asghar Sarchahi
- Faculty of Veterinary Medicine, Department of Clinical Sciences Ferdowsi University of Mashhad Mashhad Iran
| | - Hossein Kazemi Mehrjerdi
- Faculty of Veterinary Medicine, Department of Clinical Sciences Ferdowsi University of Mashhad Mashhad Iran
| |
Collapse
|
2
|
van der Kolk MR, Jansen MACH, Rutjes FPJT, Blanco-Ania D. CYCLOBUTANES IN SMALL MOLECULE DRUG CANDIDATES. ChemMedChem 2022; 17:e202200020. [PMID: 35263505 PMCID: PMC9314592 DOI: 10.1002/cmdc.202200020] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/05/2022] [Indexed: 11/13/2022]
Abstract
Cyclobutanes are increasingly used in medicinal chemistry in the search for relevant biological properties. Important characteristics of the cyclobutane ring include its unique puckered structure, longer C−C bond lengths, increased C−C π‐character and relative chemical inertness for a highly strained carbocycle. This review will focus on contributions of cyclobutane rings in drug candidates to arrive at favorable properties. Cyclobutanes have been employed for improving multiple factors such as preventing cis/trans‐isomerization by replacing alkenes, replacing larger cyclic systems, increasing metabolic stability, directing key pharmacophore groups, inducing conformational restriction, reducing planarity, as aryl isostere and filling hydrophobic pockets.
Collapse
Affiliation(s)
- Marnix R van der Kolk
- Radboud University Institute for Molecules and Materials: Radboud Universiteit Institute for Molecules and Materials, Synthetic Organic Chemistry, Heyendaalseweg 135, 6525AJ, Nijmegen, NETHERLANDS
| | - Mathilde A C H Jansen
- Radboud University Institute for Molecules and Materials: Radboud Universiteit Institute for Molecules and Materials, Synthetic Organic Chemistry, Heyendaalseweg 135, 6525AJ, Nijmegen, NETHERLANDS
| | - Floris P J T Rutjes
- Radboud University Institute for Molecules and Materials: Radboud Universiteit Institute for Molecules and Materials, Synthetic Organic Chemistry, Heyendaalseweg 135, 6525AJ, Nijmegen, NETHERLANDS
| | - Daniel Blanco-Ania
- Radboud University, Cluster for Molecular Chemistry, Heyendaalaseweg 135, 6525 AJ, Nijmegen, NETHERLANDS
| |
Collapse
|
3
|
New sulfonyl hydrazones and their Pd(II) complexes: synthesis and cytotoxic activities in the MDA-MB-231 cell line. CHEMICAL PAPERS 2021. [DOI: 10.1007/s11696-021-01928-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
4
|
Two Decades of 4D-QSAR: A Dying Art or Staging a Comeback? Int J Mol Sci 2021; 22:ijms22105212. [PMID: 34069090 PMCID: PMC8156896 DOI: 10.3390/ijms22105212] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 01/01/2023] Open
Abstract
A key question confronting computational chemists concerns the preferable ligand geometry that fits complementarily into the receptor pocket. Typically, the postulated ‘bioactive’ 3D ligand conformation is constructed as a ‘sophisticated guess’ (unnecessarily geometry-optimized) mirroring the pharmacophore hypothesis—sometimes based on an erroneous prerequisite. Hence, 4D-QSAR scheme and its ‘dialects’ have been practically implemented as higher level of model abstraction that allows the examination of the multiple molecular conformation, orientation and protonation representation, respectively. Nearly a quarter of a century has passed since the eminent work of Hopfinger appeared on the stage; therefore the natural question occurs whether 4D-QSAR approach is still appealing to the scientific community? With no intention to be comprehensive, a review of the current state of art in the field of receptor-independent (RI) and receptor-dependent (RD) 4D-QSAR methodology is provided with a brief examination of the ‘mainstream’ algorithms. In fact, a myriad of 4D-QSAR methods have been implemented and applied practically for a diverse range of molecules. It seems that, 4D-QSAR approach has been experiencing a promising renaissance of interests that might be fuelled by the rising power of the graphics processing unit (GPU) clusters applied to full-atom MD-based simulations of the protein-ligand complexes.
Collapse
|
5
|
Dimitrov IV, Suonio EEK. Syntheses of Analogues of Propofol: A Review. SYNTHESIS-STUTTGART 2020. [DOI: 10.1055/s-0040-1707287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractPropofol (2,6-diisopropylphenol) is an intravenous sedative/hypnotic agent that is used extensively for introduction and maintenance of general anaesthesia, sedation of critically ill patients and procedural sedation (e.g., endoscopy). Propofol has a rapid onset and offset of action and shows only minimal accumulation upon prolonged use. Propofol is only sparingly soluble in water and is currently marketed in 10% soybean oil-based lipid emulsion. Propofol’s anaesthetic properties were discovered over forty years ago, and it has been in clinical use for over thirty years. The main use of propofol remains as an anaesthetic but, over the years, analogues have been developed with varying properties from anticancer, anticonvulsant and antioxidant. In addition, large synthetic efforts have been made towards improving propofol’s water-solubility, its activity, and elucidating its structure–activity relationship and exact mechanism of action have been made. This review provides an overview of the research pertaining to propofol-like molecules and covers the efforts of synthetic chemists towards propofol analogues over the last 40 years.1 Introduction2 History3 Early Work4 Improving Water Solubility5 The Importance of the Phenol6 Exploring the Structure–Activity Relationship and Attempts to Improve Activity7 Anticancer Activity8 Anticonvulsant Properties9 Antioxidant Activity10 Photoactive Labelling to Elucidate Mechanism of Action11 Photoregulation12 Conclusion
Collapse
Affiliation(s)
- Ivaylo V. Dimitrov
- Auckland Cancer Society Research Centre, School of Medical Sciences, University of Auckland
| | | |
Collapse
|
6
|
Kim JJ, Gharpure A, Teng J, Zhuang Y, Howard RJ, Zhu S, Noviello CM, Walsh RM, Lindahl E, Hibbs RE. Shared structural mechanisms of general anaesthetics and benzodiazepines. Nature 2020; 585:303-308. [PMID: 32879488 PMCID: PMC7486282 DOI: 10.1038/s41586-020-2654-5] [Citation(s) in RCA: 164] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 06/01/2020] [Indexed: 01/17/2023]
Abstract
Most general anaesthetics and classical benzodiazepine drugs act through positive modulation of γ-aminobutyric acid type A (GABAA) receptors to dampen neuronal activity in the brain1-5. However, direct structural information on the mechanisms of general anaesthetics at their physiological receptor sites is lacking. Here we present cryo-electron microscopy structures of GABAA receptors bound to intravenous anaesthetics, benzodiazepines and inhibitory modulators. These structures were solved in a lipidic environment and are complemented by electrophysiology and molecular dynamics simulations. Structures of GABAA receptors in complex with the anaesthetics phenobarbital, etomidate and propofol reveal both distinct and common transmembrane binding sites, which are shared in part by the benzodiazepine drug diazepam. Structures in which GABAA receptors are bound by benzodiazepine-site ligands identify an additional membrane binding site for diazepam and suggest an allosteric mechanism for anaesthetic reversal by flumazenil. This study provides a foundation for understanding how pharmacologically diverse and clinically essential drugs act through overlapping and distinct mechanisms to potentiate inhibitory signalling in the brain.
Collapse
Affiliation(s)
- Jeong Joo Kim
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Anant Gharpure
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jinfeng Teng
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yuxuan Zhuang
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Rebecca J Howard
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Shaotong Zhu
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Colleen M Noviello
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Richard M Walsh
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Erik Lindahl
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
- Department of Applied Physics, Swedish e-Science Research Center, KTH Royal Institute of Technology, Solna, Sweden
| | - Ryan E Hibbs
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
7
|
Sahin K, Saripinar E. A novel hybrid method named electron conformational genetic algorithm as a 4D QSAR investigation to calculate the biological activity of the tetrahydrodibenzazosines. J Comput Chem 2020; 41:1091-1104. [PMID: 32058616 DOI: 10.1002/jcc.26154] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 11/11/2022]
Abstract
To understand the structure-activity correlation of a group of tetrahydrodibenzazocines as inhibitors of 17β-hydroxysteroid dehydrogenase type 3, we have performed a combined genetic algorithm (GA) and four-dimensional quantitative structure-activity relationship (4D-QSAR) modeling study. The computed electronic and geometry structure descriptors were regulated as a matrix and named as electron-conformational matrix of contiguity (ECMC). A chemical property-based pharmacophore model was developed for series of tetrahydrodibenzazocines by EMRE software package. GA was employed to choose an optimal combination of parameters. A model has been developed for estimating anticancer activity quantitatively. All QSAR models were established with 40 compounds (training set), then they were considered for selective capability with additional nine compounds (test set). A statistically valid 4D-QSAR ( R training 2 = 0.856 , R test 2 = 0.851 and q2 = 0.650) with good external set prediction was obtained.
Collapse
Affiliation(s)
- Kader Sahin
- Computational Biology and Molecular Simulations Laboratory, Department of Biophysics, School of Medicine, Bahcesehir University, Istanbul, Turkey
| | - Emin Saripinar
- Science Faculty, Department of Chemistry, Erciyes University, Kayseri, Turkey
| |
Collapse
|
8
|
Solomon VR, Tallapragada VJ, Chebib M, Johnston G, Hanrahan JR. GABA allosteric modulators: An overview of recent developments in non-benzodiazepine modulators. Eur J Med Chem 2019; 171:434-461. [DOI: 10.1016/j.ejmech.2019.03.043] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 02/17/2019] [Accepted: 03/17/2019] [Indexed: 01/13/2023]
|
9
|
Jayakar SS, Zhou X, Chiara DC, Jarava-Barrera C, Savechenkov PY, Bruzik KS, Tortosa M, Miller KW, Cohen JB. Identifying Drugs that Bind Selectively to Intersubunit General Anesthetic Sites in the α1 β3 γ2 GABA AR Transmembrane Domain. Mol Pharmacol 2019; 95:615-628. [PMID: 30952799 DOI: 10.1124/mol.118.114975] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 03/29/2019] [Indexed: 12/19/2022] Open
Abstract
GABAA receptors (GABAARs) are targets for important classes of clinical agents (e.g., anxiolytics, anticonvulsants, and general anesthetics) that act as positive allosteric modulators (PAMs). Previously, using photoreactive analogs of etomidate ([3H]azietomidate) and mephobarbital [[3H]1-methyl-5-allyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid ([3H]R-mTFD-MPAB)], we identified two homologous but pharmacologically distinct classes of general anesthetic binding sites in the α1β3γ2 GABAAR transmembrane domain at β +-α - (β + sites) and α +-β -/γ +-β - (β - sites) subunit interfaces. We now use competition photolabeling with [3H]azietomidate and [3H]R-mTFD-MPAB to identify para-substituted propofol analogs and other drugs that bind selectively to intersubunit anesthetic sites. Propofol and 4-chloro-propofol bind with 5-fold selectivity to β +, while derivatives with bulkier lipophilic substitutions [4-(tert-butyl)-propofol and 4-(hydroxyl(phenyl)methyl)-propofol] bind with ∼10-fold higher affinity to β - sites. Similar to R-mTFD-MPAB and propofol, these drugs bind in the presence of GABA with similar affinity to the α +-β - and γ +-β - sites. However, we discovered four compounds that bind with different affinities to the two β - interface sites. Two of these bind with higher affinity to one of the β - sites than to the β + sites. We deduce that 4-benzoyl-propofol binds with >100-fold higher affinity to the γ +-β - site than to the α +-β - or β +-α - sites, whereas loreclezole, an anticonvulsant, binds with 5- and 100-fold higher affinity to the α +-β - site than to the β + and γ +-β - sites. These studies provide a first identification of PAMs that bind selectively to a single intersubunit site in the GABAAR transmembrane domain, a property that may facilitate the development of subtype selective GABAAR PAMs.
Collapse
Affiliation(s)
- Selwyn S Jayakar
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - Xiaojuan Zhou
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - David C Chiara
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - Carlos Jarava-Barrera
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - Pavel Y Savechenkov
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - Karol S Bruzik
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - Mariola Tortosa
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - Keith W Miller
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| | - Jonathan B Cohen
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts (S.S.J., D.C.C., J.B.C.); Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts (X.Z., K.W.M.); Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois (P.Y.S., K.S.B.); and the Departamento de Quimica Orgánica, Universidad Autónoma de Madrid, Madrid, Spain (C.J.-B., M.T.)
| |
Collapse
|
10
|
Joyce RL, Beyer NP, Vasilopoulos G, Woll KA, Hall AC, Eckenhoff RG, Barman DN, Warren JD, Tibbs GR, Goldstein PA. Alkylphenol inverse agonists of HCN1 gating: H-bond propensity, ring saturation and adduct geometry differentially determine efficacy and potency. Biochem Pharmacol 2019; 163:493-508. [PMID: 30768926 DOI: 10.1016/j.bcp.2019.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
Abstract
BACKGROUND AND PURPOSE In models of neuropathic pain, inhibition of HCN1 is anti-hyperalgesic. 2,6-di-iso-propyl phenol (propofol) and its non-anesthetic congener, 2,6-di-tert-butyl phenol, inhibit HCN1 channels by stabilizing closed state(s). EXPERIMENTAL APPROACH Using in vitro electrophysiology and kinetic modeling, we systematically explore the contribution of ligand architecture to alkylphenol-channel coupling. KEY RESULTS When corrected for changes in hydrophobicity (and propensity for intra-membrane partitioning), the decrease in potency upon 1-position substitution (NCO∼OH >> SH >>> F) mirrors the ligands' H-bond acceptor (NCO > OH > SH >>> F) but not donor profile (OH > SH >>> NCO∼F). H-bond elimination (OH to F) corresponds to a ΔΔG of ∼4.5 kCal mol-1 loss of potency with little or no disruption of efficacy. Substitution of compact alkyl groups (iso-propyl, tert-butyl) with shorter (ethyl, methyl) or more extended (sec-butyl) adducts disrupts both potency and efficacy. Ring saturation (with the obligate loss of both planarity and π electrons) primarily disrupts efficacy. CONCLUSIONS AND IMPLICATIONS A hydrophobicity-independent decrement in potency at higher volumes suggests the alkylbenzene site has a volume of ≥800 Å3. Within this, a relatively static (with respect to ligand) H-bond donor contributes to initial binding with little involvement in generation of coupling energy. The influence of π electrons/ring planarity and alkyl adducts on efficacy reveals these aspects of the ligand present towards a face of the channel that undergoes structural changes during opening. The site's characteristics suggest it is "druggable"; introduction of other adducts on the ring may generate higher potency inverse agonists.
Collapse
Affiliation(s)
| | | | | | - Kellie A Woll
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Adam C Hall
- Smith College, Northampton, MA, United States
| | - Roderic G Eckenhoff
- University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | | | | | | | | |
Collapse
|
11
|
Niga P, Hansson-Mille PM, Swerin A, Claesson PM, Schoelkopf J, Gane PAC, Bergendal E, Tummino A, Campbell RA, Magnus Johnson C. Interactions between model cell membranes and the neuroactive drug propofol. J Colloid Interface Sci 2018; 526:230-243. [PMID: 29734090 DOI: 10.1016/j.jcis.2018.03.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 12/13/2022]
Abstract
Vibrational sum frequency spectroscopy (VSFS) complemented by surface pressure isotherm and neutron reflectometry (NR) experiments were employed to investigate the interactions between propofol, a small amphiphilic molecule that currently is the most common general anaesthetic drug, and phospholipid monolayers. A series of biologically relevant saturated phospholipids of varying chain length from C18 to C14 were spread on either pure water or propofol (2,6-bis(1-methylethyl)phenol) solution in a Langmuir trough, and the change in the molecular structure of the film, induced by the interaction with propofol, was studied with respect to the surface pressure. The results from the surface pressure isotherm experiments revealed that propofol, as long as it remains at the interface, enhances the fluidity of the phospholipid monolayer. The VSF spectra demonstrate that for each phospholipid the amount of propofol in the monolayer region decreases with increasing surface pressure. Such squeeze out is in contrast to the enhanced interactions that can be exhibited by more complex amphiphilic molecules such as peptides. At surface pressures of 22-25 mN m-1, which are relevant for biological cell membranes, most of the propofol has been expelled from the monolayer, especially in the case of the C16 and C18 phospholipids that adopt a liquid condensed phase packing of its alkyl tails. At lower surface pressures of 5 mN m-1, the effect of propofol on the structure of the alkyl tails is enhanced when the phospholipids are present in a liquid expanded phase. Specifically, for the C16 phospholipid, NR data reveal that propofol is located exclusively in the head group region, which is rationalized in the context of previous studies. The results imply a non-homogeneous distribution of propofol in the plane of real cell membranes, which is an inference that requires urgent testing and may help to explain why such low concentration of the drug are required to induce general anaesthesia.
Collapse
Affiliation(s)
- Petru Niga
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden.
| | - Petra M Hansson-Mille
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden
| | - Agne Swerin
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden; KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden
| | - Per M Claesson
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden; KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden
| | | | - Patrick A C Gane
- Omya International AG, Baslerstrasse 42, CH-4665 Oftringen, Switzerland; Aalto University, School of Chemical Engineering, Department of Bioproducts and Biosystems, P.O. Box 16300, FI-00076 Aalto, Helsinki, Finland
| | - Erik Bergendal
- KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden
| | - Andrea Tummino
- Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble, France; Eötvös Loránd University, Budapest 112, P.O. Box 32, H-1518, Hungary
| | | | - C Magnus Johnson
- KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
| |
Collapse
|
12
|
Kumar RP, Kulkarni N. A receptor dependent-4D QSAR approach to predict the activity of mutated enzymes. Sci Rep 2017; 7:6273. [PMID: 28740233 PMCID: PMC5524700 DOI: 10.1038/s41598-017-06625-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 06/15/2017] [Indexed: 11/29/2022] Open
Abstract
Screening and selection tools to obtain focused libraries play a key role in successfully engineering enzymes of desired qualities. The quality of screening depends on efficient assays; however, a focused library generated with a priori information plays a major role in effectively identifying the right enzyme. As a proof of concept, for the first time, receptor dependent - 4D Quantitative Structure Activity Relationship (RD-4D-QSAR) has been implemented to predict kinetic properties of an enzyme. The novelty of this study is that the mutated enzymes also form a part of the training data set. The mutations were modeled in a serine protease and molecular dynamics simulations were conducted to derive enzyme-substrate (E-S) conformations. The E-S conformations were enclosed in a high resolution grid consisting of 156,250 grid points that stores interaction energies to generate QSAR models to predict the enzyme activity. The QSAR predictions showed similar results as reported in the kinetic studies with >80% specificity and >50% sensitivity revealing that the top ranked models unambiguously differentiated enzymes with high and low activity. The interaction energy descriptors of the best QSAR model were used to identify residues responsible for enzymatic activity and substrate specificity.
Collapse
Affiliation(s)
- R Pravin Kumar
- Polyclone Bioservices, #437, 40th Cross, Jayanagar 5th Block, Bangalore, 560041, India.
| | - Naveen Kulkarni
- Polyclone Bioservices, #437, 40th Cross, Jayanagar 5th Block, Bangalore, 560041, India
| |
Collapse
|
13
|
Qiu L, Lin J, Liu Q, Wang S, Lv G, Li K, Shi H, Huang Z, Bertaccini EJ. The Role of the Hydroxyl Group in Propofol-Protein Target Recognition: Insights from ONIOM Studies. J Phys Chem B 2017; 121:5883-5896. [PMID: 28548837 DOI: 10.1021/acs.jpcb.7b02079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Propofol (PFL, 1-hydroxyl-2,6-diisopropylbenzene) is currently used widely as one of the most well-known intravenous anesthetics to relieve surgical suffering, but its mechanism of action is not yet clear. Previous experimental studies have demonstrated that the hydroxyl group of PFL plays a dominant role in the molecular recognition of PFL with receptors that lead to hypnosis. To further explore the mechanism of anesthesia induced by PFL in the present work, the exact binding features and interaction details of PFL with three important proteins, human serum albumin (HSA), the pH-gated ion channel from Gloeobacter violaceus (GLIC), and horse spleen apoferritin (HSAF), were investigated systematically by using a rigorous three-layer ONIOM (M06-2X/6-31+G*:PM6:AMBER) method. Additionally, to further characterize the possible importance of such hydroxyl interactions, a similar set of calculations was carried out on the anesthetically inactive fropofol (FFL, 1-fluoro-2,6-diisopropylbenzene) in which the fluorine was substituted for the hydroxyl. According to the ONIOM calculations, atoms in molecules (AIM) analyses, and electrostatic potential (ESP) analyses, the significance of hydrogen bond, halogen bond, and hydrophobic interactions in promoting proper molecular recognition was revealed. The binding interaction energies of PFL with different proteins were generally larger than FFL and are a significant determinant of their differential anesthetic efficacies. Interestingly, although the hydrogen-bonding effect of the hydroxyl moiety was prominent in propofol, the substitution of the 1-hydroxyl by a fluorine atom did not prevent FFL from binding to the protein via a halogen-bonding interaction. It therefore became clear that multiple specific interactions rather than just hydrogen or halogen bonds must be taken into account to explain the different anesthesia endpoints caused by PFL and FFL. The contributions of key residues in ligand-receptor binding were also quantified, and the calculated results agreed with many available experimental observations. This work will provide complementary insights into the molecular mechanisms of anesthetic action for PFL from a robust theoretical point of view. This will not only assist in interpreting experimental observations but will also help to develop working hypotheses for further experiments and future drug design.
Collapse
Affiliation(s)
- Ling Qiu
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China.,Department of Anesthesia, Stanford University School of Medicine , 300 Pasteur Drive, Stanford, California 94305, United States
| | - Jianguo Lin
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China
| | - Qingzhu Liu
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China
| | - Shanshan Wang
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China
| | - Gaochao Lv
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China
| | - Ke Li
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China
| | - Haiming Shi
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China
| | - Zhengkun Huang
- Key Laboratory of Nuclear Medicine, Ministry of Health, & Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine , Wuxi 214063, P. R. China
| | - Edward J Bertaccini
- Department of Anesthesia, Stanford University School of Medicine , 300 Pasteur Drive, Stanford, California 94305, United States.,Palo Alto VA Health Care System, 112A, PAVAHCS , 3801 Miranda Avenue, Palo Alto, California 94304, United States
| |
Collapse
|
14
|
Zhang C, Li F, Yu Y, Huang A, He P, Lei M, Wang J, Huang L, Liu Z, Liu J, Wei Y. Design, Synthesis, and Evaluation of a Series of Novel Benzocyclobutene Derivatives as General Anesthetics. J Med Chem 2017; 60:3618-3625. [PMID: 28430431 DOI: 10.1021/acs.jmedchem.7b00253] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Chen Zhang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Fangqiong Li
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Yan Yu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Anbang Huang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Ping He
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Ming Lei
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Jianmin Wang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Longbin Huang
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Zhenhong Liu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Jianyu Liu
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| | - Yonggang Wei
- Haisco Pharmaceutical Group Co. Ltd., 136 Baili Road, Wenjiang district, Chengdu 611130, China
| |
Collapse
|
15
|
Curcumol allosterically modulates GABA(A) receptors in a manner distinct from benzodiazepines. Sci Rep 2017; 7:46654. [PMID: 28436443 PMCID: PMC5402396 DOI: 10.1038/srep46654] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 03/22/2017] [Indexed: 12/11/2022] Open
Abstract
Inhibitory A type γ-aminobutyric acid receptors (GABAARs) play a pivotal role in orchestrating various brain functions and represent an important molecular target in neurological and psychiatric diseases, necessitating the need for the discovery and development of novel modulators. Here, we show that a natural compound curcumol, acts as an allosteric enhancer of GABAARs in a manner distinct from benzodiazepines. Curcumol markedly facilitated GABA-activated currents and shifted the GABA concentration-response curve to the left in cultured hippocampal neurons. When co-applied with the classical benzodiazepine diazepam, curcumol further potentiated GABA-induced currents. In contrast, in the presence of a saturating concentration of menthol, a positive modulator for GABAAR, curcumol failed to further enhance GABA-induced currents, suggesting shared mechanisms underlying these two agents on GABAARs. Moreover, the benzodiazepine antagonist flumazenil did not alter the enhancement of GABA response by curcumol and menthol, but abolished that by DZP. Finally, mutations at the β2 or γ2 subunit predominantly eliminated modulation of recombinant GABAARs by curcumol and menthol, or diazepam, respectively. Curcumol may therefore exert its actions on GABAARs at sites distinct from benzodiazepine sites. These findings shed light on the future development of new therapeutics drugs targeting GABAARs.
Collapse
|
16
|
Woll KA, Murlidaran S, Pinch BJ, Hénin J, Wang X, Salari R, Covarrubias M, Dailey WP, Brannigan G, Garcia BA, Eckenhoff RG. A Novel Bifunctional Alkylphenol Anesthetic Allows Characterization of γ-Aminobutyric Acid, Type A (GABAA), Receptor Subunit Binding Selectivity in Synaptosomes. J Biol Chem 2016; 291:20473-86. [PMID: 27462076 PMCID: PMC5034043 DOI: 10.1074/jbc.m116.736975] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/25/2016] [Indexed: 12/19/2022] Open
Abstract
Propofol, an intravenous anesthetic, is a positive modulator of the GABAA receptor, but the mechanistic details, including the relevant binding sites and alternative targets, remain disputed. Here we undertook an in-depth study of alkylphenol-based anesthetic binding to synaptic membranes. We designed, synthesized, and characterized a chemically active alkylphenol anesthetic (2-((prop-2-yn-1-yloxy)methyl)-5-(3-(trifluoromethyl)-3H-diazirin-3-yl)phenol, AziPm-click (1)), for affinity-based protein profiling (ABPP) of propofol-binding proteins in their native state within mouse synaptosomes. The ABPP strategy captured ∼4% of the synaptosomal proteome, including the unbiased capture of five α or β GABAA receptor subunits. Lack of γ2 subunit capture was not due to low abundance. Consistent with this, independent molecular dynamics simulations with alchemical free energy perturbation calculations predicted selective propofol binding to interfacial sites, with higher affinities for α/β than γ-containing interfaces. The simulations indicated hydrogen bonding is a key component leading to propofol-selective binding within GABAA receptor subunit interfaces, with stable hydrogen bonds observed between propofol and α/β cavity residues but not γ cavity residues. We confirmed this by introducing a hydrogen bond-null propofol analogue as a protecting ligand for targeted-ABPP and observed a lack of GABAA receptor subunit protection. This investigation demonstrates striking interfacial GABAA receptor subunit selectivity in the native milieu, suggesting that asymmetric occupancy of heteropentameric ion channels by alkylphenol-based anesthetics is sufficient to induce modulation of activity.
Collapse
Affiliation(s)
- Kellie A Woll
- From the Departments of Anesthesiology and Critical Care and Pharmacology and
| | | | - Benika J Pinch
- the Department of Chemistry, University of Pennsylvania School of Arts and Sciences, Philadelphia, Pennsylvania 19104
| | - Jérôme Hénin
- the Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, CNRS UMR 8251 and Université Paris Diderot, 5013 Paris, France, and
| | - Xiaoshi Wang
- the Epigenetics Program, Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Reza Salari
- the Center for Computational and Integrative Biology and Department of Physics, Rutgers University, Camden, New Jersey 08102
| | - Manuel Covarrubias
- the Department of Neuroscience and Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - William P Dailey
- the Department of Chemistry, University of Pennsylvania School of Arts and Sciences, Philadelphia, Pennsylvania 19104
| | - Grace Brannigan
- the Center for Computational and Integrative Biology and Department of Physics, Rutgers University, Camden, New Jersey 08102
| | - Benjamin A Garcia
- the Epigenetics Program, Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | | |
Collapse
|
17
|
A Cysteine Substitution Probes β3H267 Interactions with Propofol and Other Potent Anesthetics in α1β3γ2L γ-Aminobutyric Acid Type A Receptors. Anesthesiology 2016; 124:89-100. [PMID: 26569173 DOI: 10.1097/aln.0000000000000934] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Anesthetic contact residues in γ-aminobutyric acid type A (GABAA) receptors have been identified using photolabels, including two propofol derivatives. O-propofol diazirine labels H267 in β3 and α1β3 receptors, whereas m-azi-propofol labels other residues in intersubunit clefts of α1β3. Neither label has been studied in αβγ receptors, the most common isoform in mammalian brain. In αβγ receptors, other anesthetic derivatives photolabel m-azi-propofol-labeled residues, but not βH267. The authors' structural homology model of α1β3γ2L receptors suggests that β3H267 may abut some of these sites. METHODS Substituted cysteine modification-protection was used to test β3H267C interactions with four potent anesthetics: propofol, etomidate, alphaxalone, and R-5-allyl-1-methyl-5-(m-trifluoromethyl-diazirinylphenyl) barbituric acid (mTFD-MPAB). The authors expressed α1β3γ2L or α1β3H267Cγ2L GABAA receptors in Xenopus oocytes. The authors used voltage clamp electrophysiology to assess receptor sensitivity to γ-aminobutyric acid (GABA) and anesthetics and to compare p-chloromercuribenzenesulfonate modification rates with GABA versus GABA plus anesthetics. RESULTS Enhancement of low GABA (eliciting 5% of maximum) responses by equihypnotic concentrations of all four anesthetics was similar in α1β3γ2L and α1β3H267Cγ2L receptors (n > 3). Direct activation of α1β3H267Cγ2L receptors, but not α1β3γ2L, by mTFD-MPAB and propofol was significantly greater than the other anesthetics. Modification of β3H267C by p-chloromercuribenzenesulfonate (n > 4) was rapid and accelerated by GABA. Only mTFD-MPAB slowed β3H267C modification (approximately twofold; P = 0.011). CONCLUSIONS β3H267 in α1β3γ2L GABAA receptors contacts mTFD-MPAB, but not propofol. The study results suggest that β3H267 is near the periphery of one or both transmembrane intersubunit (α+/β- and γ+/β-) pockets where both mTFD-MPAB and propofol bind.
Collapse
|
18
|
de Assis TM, Gajo GC, de Assis LC, Garcia LS, Silva DR, Ramalho TC, da Cunha EFF. QSAR Models Guided by Molecular Dynamics Applied to Human Glucokinase Activators. Chem Biol Drug Des 2015; 87:455-66. [DOI: 10.1111/cbdd.12683] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 10/05/2015] [Accepted: 10/22/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Tamiris Maria de Assis
- Department of Chemistry; Federal University of Lavras; P.O. Box 3037 Lavras 37200-000 Brazil
| | - Giovanna Cardoso Gajo
- Department of Chemistry; Federal University of Lavras; P.O. Box 3037 Lavras 37200-000 Brazil
| | | | - Letícia Santos Garcia
- Department of Chemistry; Federal University of Lavras; P.O. Box 3037 Lavras 37200-000 Brazil
| | - Daniela Rodrigues Silva
- Department of Chemistry; Federal University of Lavras; P.O. Box 3037 Lavras 37200-000 Brazil
| | - Teodorico Castro Ramalho
- Department of Chemistry; Federal University of Lavras; P.O. Box 3037 Lavras 37200-000 Brazil
- Center for Basic and Applied Research; Faculty of Informatics and Management; University of Hradec Kralove; Hradec Kralove Czech Republic
| | | |
Collapse
|
19
|
Wang T, Wu MB, Lin JP, Yang LR. Quantitative structure–activity relationship: promising advances in drug discovery platforms. Expert Opin Drug Discov 2015; 10:1283-300. [DOI: 10.1517/17460441.2015.1083006] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
20
|
Han D, Jin J, Fang H, Xu G. Long-term action of propofol on cognitive function and hippocampal neuroapoptosis in neonatal rats. Int J Clin Exp Med 2015; 8:10696-10704. [PMID: 26379861 PMCID: PMC4565244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/26/2015] [Indexed: 06/05/2023]
Abstract
Propofol is a short-acting anesthetic and generally is utilized for the induction and maintenance of anesthesia in pediatrics and adults. However, whether repeated use of propofol affects long-term cognitive function remains unclear. This study investigated the effects of propofol on cognitive function and hippocampal neuroapoptosis in neonatal rat. A total of 112 male newborn 7-day old Sprague-Dawley rats were randomly divided into 8 groups (n=14 rats per group) and intraperitoneally injected either with saline or propofol at 50, 100, and 150 mg/kg/day for 5 consecutive days. Four non-surgical groups were assigned as Con1, P50, P100, and P150. Four surgical groups were received an appendicectomy under propofol anesthesia and assigned as Con2, SP50, SP100, SP150. After 2 months raising, cognitive function, hippocampal neuroapoptosis, and intracephalic inflammatory cytokines were evaluated. There was no obvious effect on the cognitive function and neuroapoptosis after repeated use of propofol at a low dose for 5 days, whereas repeated use of propofol at a middle/high dose significantly increase the expression of apoptotic factors (caspase-3 and Bax), pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), and impair the cognitive function. Thus, our data suggest that repeated use of propofol at a low dose may be safe during the period of brain growth spurt. Using propofol at a recommended or higher dose for anaesthesia may lead to the cognitive defects, attributed to hippocampal neuroapoptosis and the overexpression of pro-inflammatory cytokines in the brain.
Collapse
Affiliation(s)
- Dan Han
- Department of Anesthesiology, Dongfang Hospital, Tongji UniversityShanghai, China
| | - Jianhua Jin
- Department of Anesthesiology, Jinshan Hospital, Fudan UniversityShanghai 201508, China
| | - Hao Fang
- Department of Anesthesiology, Jinshan Hospital, Fudan UniversityShanghai 201508, China
| | - Guoxiong Xu
- Center Laboratory, Jinshan Hospital, Fudan UniversityShanghai 201508, China
| |
Collapse
|
21
|
Woll KA, Weiser BP, Liang Q, Meng T, McKinstry-Wu A, Pinch B, Dailey WP, Gao WD, Covarrubias M, Eckenhoff RG. Role for the propofol hydroxyl in anesthetic protein target molecular recognition. ACS Chem Neurosci 2015; 6:927-35. [PMID: 25799399 DOI: 10.1021/acschemneuro.5b00078] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Propofol is a widely used intravenous general anesthetic. We synthesized 2-fluoro-1,3-diisopropylbenzene, a compound that we call "fropofol", to directly assess the significance of the propofol 1-hydroxyl for pharmacologically relevant molecular recognition in vitro and for anesthetic efficacy in vivo. Compared to propofol, fropofol had a similar molecular volume and only a small increase in hydrophobicity. Isothermal titration calorimetry and competition assays revealed that fropofol had higher affinity for a protein site governed largely by van der Waals interactions. Within another protein model containing hydrogen bond interactions, propofol demonstrated higher affinity. In vivo, fropofol demonstrated no anesthetic efficacy, but at high concentrations produced excitatory activity in tadpoles and mice; fropofol also antagonized propofol-induced hypnosis. In a propofol protein target that contributes to hypnosis, α1β2γ2L GABAA receptors, fropofol demonstrated no significant effect alone or on propofol positive allosteric modulation of the ion channel, suggesting an additional requirement for the 1-hydroxyl within synaptic GABAA receptor site(s). However, fropofol caused similar adverse cardiovascular effects as propofol by a dose-dependent depression of myocardial contractility. Our results directly implicate the propofol 1-hydroxyl as contributing to molecular recognition within protein targets leading to hypnosis, but not necessarily within protein targets leading to side effects of the drug.
Collapse
Affiliation(s)
| | | | - Qiansheng Liang
- Department
of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, 900 Walnut Street, JHN 417, Philadelphia, Pennsylvania 19107, United States
| | - Tao Meng
- Department of Anesthesiology, Qilu Hospital, Shandong University, 107 Wenhua Xi Road, Jinan, 250012 P. R. China
- Department of Anesthesiology
and Critical Care Medicine, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, Maryland 21287, United States
| | | | - Benika Pinch
- Department of Chemistry, University of Pennsylvania School of Arts and Sciences, 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - William P. Dailey
- Department of Chemistry, University of Pennsylvania School of Arts and Sciences, 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Wei Dong Gao
- Department of Anesthesiology
and Critical Care Medicine, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, Maryland 21287, United States
| | - Manuel Covarrubias
- Department
of Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, 900 Walnut Street, JHN 417, Philadelphia, Pennsylvania 19107, United States
| | | |
Collapse
|
22
|
Khajuria A, Tay C, Shi J, Zhao H, Ma D. Anesthetics attenuate ischemia–reperfusion induced renal injury: Effects and mechanisms. ACTA ACUST UNITED AC 2014; 52:176-84. [DOI: 10.1016/j.aat.2014.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/01/2014] [Indexed: 12/17/2022]
|
23
|
TIAN X, XIANG Y, FAN Y, BU H, YANG H, MANYANDE A, GAO F, TIAN Y. Impact of malnutrition on propofol consumption and recovery time among patients undergoing laparoscopic gastrointestinal surgery. Acta Anaesthesiol Scand 2014; 58:942-7. [PMID: 25060045 DOI: 10.1111/aas.12373] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND Malnutrition is a major health problem, especially in hospitalized patients as it can be closely related to many post-operative complications. However, research on malnutrition and its effect on the outcome of general anesthesia have been largely neglected. Here we investigated malnutrition status on propofol consumption and recovery time among patients undergoing laparoscopic gastrointestinal surgery under general anesthesia. METHODS One hundred and one patients were recruited between January and June 2012 at Tongji Hospital and assigned into three groups according to Nutritional Risk Screening Tool 2002 score. A standard combined general anesthesia procedure was performed under regular monitoring. The dosage of propofol needed for induction, consumption during maintenance and recovery time were recorded. RESULTS When compared with normal nutritional status individuals, the propofol dosage at induction was significantly decreased about 4.3% in moderate malnutritional status patients (P < 0.01) and about 16.8% in severely malnutritional status patients (P < 0.01). The average consumption of propofol was also significantly lower in malnourished individuals; for moderate malnutritional, the decrease was about 20% (P < 0.01) while for the severely malnutritional, it was 30% (P < 0.01) when compared with normal nutritional status individuals. For the recovery time of propofol anesthesia, the patients with severe malnutritional status awoke average 6.8 min later than those normally nourished (P < 0.01), but those patients with moderate malnutrition status did not (P = 0.885). CONCLUSION The present results indicate that the dosage and recovery time of propofol does change in malnourished individuals. Therefore, malnutrition may somehow affect the outcome of general anesthesia.
Collapse
Affiliation(s)
- X. TIAN
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| | - Y. XIANG
- Department of Ophthalmology; Tongji Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| | - Y. FAN
- Department of Nutrition and Food Hygiene; School of Public Health; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| | - H. BU
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| | - H. YANG
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| | - A. MANYANDE
- School of Psychology; Social Work and Human Sciences; University of West London; London UK
| | - F. GAO
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| | - Y. TIAN
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| |
Collapse
|
24
|
Quantitative structure–activity relationship (QSAR) studies as strategic approach in drug discovery. Med Chem Res 2014. [DOI: 10.1007/s00044-014-1072-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
25
|
Assessment of homology templates and an anesthetic binding site within the γ-aminobutyric acid receptor. Anesthesiology 2013; 119:1087-95. [PMID: 23770602 DOI: 10.1097/aln.0b013e31829e47e3] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Anesthetics mediate portions of their activity via modulation of the γ-aminobutyric acid receptor (GABAaR). Although its molecular structure remains unknown, significant progress has been made toward understanding its interactions with anesthetics via molecular modeling. METHODS The structure of the torpedo acetylcholine receptor (nAChRα), the structures of the α4 and β2 subunits of the human nAChR, the structures of the eukaryotic glutamate-gated chloride channel (GluCl), and the prokaryotic pH-sensing channels, from Gloeobacter violaceus and Erwinia chrysanthemi, were aligned with the SAlign and 3DMA algorithms. A multiple sequence alignment from these structures and those of the GABAaR was performed with ClustalW. The Modeler and Rosetta algorithms independently created three-dimensional constructs of the GABAaR from the GluCl template. The CDocker algorithm docked a congeneric series of propofol derivatives into the binding pocket and scored calculated binding affinities for correlation with known GABAaR potentiation EC50s. RESULTS Multiple structure alignments of templates revealed a clear consensus of residue locations relevant to anesthetic effects except for torpedo nAChR. Within the GABAaR models generated from GluCl, the residues notable for modulating anesthetic action within transmembrane segments 1, 2, and 3 converged on the intersubunit interface between α and β subunits. Docking scores of a propofol derivative series into this binding site showed strong linear correlation with GABAaR potentiation EC50. CONCLUSION Consensus structural alignment based on homologous templates revealed an intersubunit anesthetic binding cavity within the transmembrane domain of the GABAaR, which showed a correlation of ligand docking scores with experimentally measured GABAaR potentiation.
Collapse
|
26
|
Propofol modulates the lipid phase transition and localizes near the headgroup of membranes. Chem Phys Lipids 2013; 175-176:84-91. [DOI: 10.1016/j.chemphyslip.2013.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/08/2013] [Accepted: 08/14/2013] [Indexed: 12/11/2022]
|
27
|
Naghibi K, Kashefi P, Abtahi AM. The comparison of preemptive effects of propofol, remifentanil and ketamine on post-operative pain scores and analgesic requirements in elective lower abdominal surgery under general anesthesia: A randomized, double-blinded study. JOURNAL OF RESEARCH IN MEDICAL SCIENCES : THE OFFICIAL JOURNAL OF ISFAHAN UNIVERSITY OF MEDICAL SCIENCES 2013; 18:567-72. [PMID: 24516488 PMCID: PMC3897023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 11/12/2012] [Accepted: 04/30/2013] [Indexed: 11/01/2022]
Abstract
BACKGROUND In this randomized, double-blinded study, we investigated the preemptive effects of propofol, remifentanil or ketamine on post-operative pain scores and analgesic requirements in elective lower abdominal surgeries under general anesthesia during the first 24 h of post-operative period. MATERIALS AND METHODS Seventy five patients, American Society of Anesthesiologists physical status I or II candidate for elective lower abdominal surgery under general anesthesia were randomized to three groups (25 each). According to their allocated group, patients received either propofol 0.25 mg/kg, remifentanil 0.25 mic/kg or ketamine 0.3 mg/kg as preemptive analgesia immediately after the induction of general anesthesia. Post-operative pain scores with a numerical rating scale (visual analogue scale 0-10) were assessed and analgesic requirements and side-effects were compared through analysis using the SPSS version 18 in the post-operative period; post-anesthesia care unit 2, 6, 12 and 24 h. RESULTS Patients' demographics were similar in all groups. The pain scores were significantly lower in remifentanil group immediately after recovery and also at 2 and 6 h post-operatively, but it reversed at 12 and 24 h after recovery comparing with propofol and ketamine. However, the mean of administered morphine in the first 24 h was significantly lower in propofol group (18.97 ± 6.6) comparing with remifentanil group (21.96 ± 6.55) and ketamine group (24.26 ± 5.84) (P value, 0.01). CONCLUSION Prophylactic preemptive single dose of intravenous (IV) 0.25 mg/kg propofol significantly decreased post-operative analgesia requirements comparing with IV 0.3 mg/kg ketamine or 0.25 μg/kg remifentanil.
Collapse
Affiliation(s)
- Khosrou Naghibi
- Department of Anesthesia and Intensive Care, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parviz Kashefi
- Department of Anesthesia and Intensive Care, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran,Address for correspondence: Dr. Parviz Kashefi, Department of Anesthesia and Intensive Care, Alzahra University Hospital, Isfahan, Iran. E-mail:
| | - Amir Mohamad Abtahi
- Department of Anesthesia and Intensive Care, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
28
|
Robust photoregulation of GABA(A) receptors by allosteric modulation with a propofol analogue. Nat Commun 2013; 3:1095. [PMID: 23033071 PMCID: PMC4023869 DOI: 10.1038/ncomms2094] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 08/29/2012] [Indexed: 01/09/2023] Open
Abstract
Photochemical switches represent a powerful method for improving pharmacological therapies and controlling cellular physiology. Here we report the photo-regulation of GABAA receptors (GABAARs) by a derivative of propofol (2,6-diisopropylphenol), a GABAAR allosteric modulator, that we have modified to contain photo-isomerizable azobenzene. Using α1β2γ2 GABAARs expressed in Xenopus laevis oocytes and native GABAARs of isolated retinal ganglion cells, we show that the trans-azobenzene isomer of the new compound (trans-MPC088), generated by visible light (wavelengths ~440 nm), potentiates the GABA-elicited response and at higher concentrations directly activates the receptors. cis-MPC088, generated from trans-MPC088 by UV light (~365 nm), produces little if any receptor potentiation/activation. In cerebellar slices, MPC088 co-applied with GABA affords bidirectional photo-modulation of Purkinje cell membrane current and spike-firing rate. The findings demonstrate photo-control of GABAARs by an allosteric ligand and open new avenues for fundamental and clinically oriented research on GABAARs, a major class of neurotransmitter receptors in the central nervous system.
Collapse
|
29
|
Tong F, Coats JR. Quantitative structure-activity relationships of monoterpenoid binding activities to the housefly GABA receptor. PEST MANAGEMENT SCIENCE 2012; 68:1122-1129. [PMID: 22461383 DOI: 10.1002/ps.3280] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 01/01/2012] [Accepted: 01/25/2012] [Indexed: 05/31/2023]
Abstract
BACKGROUND Monoterpenoids are a large group of plant secondary metabolites. Many of these naturally occurring compounds have shown good insecticidal potency on pest insects. Previous studies in this laboratory have indicated that some monoterpenoids have positive modulatory effects on insect GABA receptors. In this study, the key properties of monoterpenoids involved in monoterpenoid binding activity at the housefly GABA receptor were determined by developing quantitative structure-activity relationship (QSAR) models, and the relationship between the toxicities of these monoterpenoids and their GABA receptor binding activities was evaluated. RESULTS Two QSAR models were determined for nine monoterpenoids showing significant effects on [³H]-TBOB binding and for nine p-menthane analogs with at least one oxygen atom attached to the ring. The Mulliken charges on certain carbon atoms, the log P value and the total energy showed significant relationships with binding activities to the housefly GABA receptor in these two QSAR models. CONCLUSIONS From the QSAR models, some chemical and structural parameters, including the electronic properties, hydrophobicity and stability of monoterpenoid molecules, were suggested to be strongly involved in binding activities to the housefly GABA receptor. These findings will help to understand the mode of action of these natural insecticides, and provide guidance to predict more monoterpenoid insecticides.
Collapse
Affiliation(s)
- Fan Tong
- Pesticide Toxicology Laboratory, Department of Entomology, Iowa State University, Ames, IA, USA
| | | |
Collapse
|
30
|
Recognition of anesthetic barbiturates by a protein binding site: a high resolution structural analysis. PLoS One 2012; 7:e32070. [PMID: 22359658 PMCID: PMC3281113 DOI: 10.1371/journal.pone.0032070] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 01/23/2012] [Indexed: 01/30/2023] Open
Abstract
Barbiturates potentiate GABA actions at the GABAA receptor and act as central nervous system depressants that can induce effects ranging from sedation to general anesthesia. No structural information has been available about how barbiturates are recognized by their protein targets. For this reason, we tested whether these drugs were able to bind specifically to horse spleen apoferritin, a model protein that has previously been shown to bind many anesthetic agents with affinities that are closely correlated with anesthetic potency. Thiopental, pentobarbital, and phenobarbital were all found to bind to apoferritin with affinities ranging from 10–500 µM, approximately matching the concentrations required to produce anesthetic and GABAergic responses. X-ray crystal structures were determined for the complexes of apoferritin with thiopental and pentobarbital at resolutions of 1.9 and 2.0 Å, respectively. These structures reveal that the barbiturates bind to a cavity in the apoferritin shell that also binds haloalkanes, halogenated ethers, and propofol. Unlike these other general anesthetics, however, which rely entirely upon van der Waals interactions and the hydrophobic effect for recognition, the barbiturates are recognized in the apoferritin site using a mixture of both polar and nonpolar interactions. These results suggest that any protein binding site that is able to recognize and respond to the chemically and structurally diverse set of compounds used as general anesthetics is likely to include a versatile mixture of both polar and hydrophobic elements.
Collapse
|
31
|
The great descriptor melting pot: mixing descriptors for the common good of QSAR models. J Comput Aided Mol Des 2011; 26:39-43. [DOI: 10.1007/s10822-011-9511-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/02/2011] [Indexed: 10/14/2022]
|
32
|
Stewart DS, Savechenkov PY, Dostalova Z, Chiara DC, Ge R, Raines DE, Cohne JB, Forman SA, Bruzik KS, Miller KW. p-(4-Azipentyl)propofol: a potent photoreactive general anesthetic derivative of propofol. J Med Chem 2011; 54:8124-35. [PMID: 22029276 PMCID: PMC3580944 DOI: 10.1021/jm200943f] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We synthesized 2,6-diisopropyl-4-[3-(3-methyl-3H-diazirin-3-yl)propyl]phenol (p-(4-azipentyl)propofol), or p-4-AziC5-Pro, a novel photoactivable derivative of the general anesthetic propofol. p-4-AziC5-Pro has an anesthetic potency similar to that of propofol. Like propofol, the compound potentiates inhibitory GABA(A) receptor current responses and allosterically modulates binding to both agonist and benzodiazepine sites, assayed on heterologously expressed GABA(A) receptors. p-4-AziC5-Pro inhibits excitatory current responses of nACh receptors expressed in Xenopus oocytes and photoincorporates into native nACh receptor-enriched Torpedo membranes. 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.
Collapse
Affiliation(s)
- Deirdre S. Stewart
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, Massachusetts 02114
| | - Pavel Y. Savechenkov
- University of Illinois at Chicago, College of Pharmacy, 833 S. Wood Street (M/C 781), Chicago, IL 60612-7231
| | - Zuzana Dostalova
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, Massachusetts 02114
| | - David C. Chiara
- Department of Neurobiology, 220 Longwood Avenue, Harvard Medical School, Boston, Massachusetts 02115
| | - Rile Ge
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, Massachusetts 02114
| | - Douglas E. Raines
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, Massachusetts 02114
| | - Jonathan B. Cohne
- Department of Neurobiology, 220 Longwood Avenue, Harvard Medical School, Boston, Massachusetts 02115
| | - Stuart A. Forman
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, Massachusetts 02114
| | - Karol S. Bruzik
- University of Illinois at Chicago, College of Pharmacy, 833 S. Wood Street (M/C 781), Chicago, IL 60612-7231
| | - Keith W. Miller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 32 Fruit Street, Boston, Massachusetts 02114
- Department of Biological Chemistry and Molecular Pharmacology, 220 Longwood Avenue, Harvard Medical School, Boston, Massachusetts 02115
| |
Collapse
|
33
|
Krasowski MD, Hopfinger AJ. The discovery of new anesthetics by targeting GABAAreceptors. Expert Opin Drug Discov 2011; 6:1187-201. [DOI: 10.1517/17460441.2011.627324] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
34
|
Hall AC, Griffith TN, Tsikolia M, Kotey FO, Gill N, Humbert DJ, Watt EE, Yermolina YA, Goel S, El-Ghendy B, Hall CD. Cyclohexanol analogues are positive modulators of GABA(A) receptor currents and act as general anaesthetics in vivo. Eur J Pharmacol 2011; 667:175-81. [PMID: 21658385 DOI: 10.1016/j.ejphar.2011.05.058] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 05/18/2011] [Accepted: 05/22/2011] [Indexed: 11/16/2022]
Abstract
GABA(A) receptors meet all the pharmacological criteria required to be considered important general anaesthetic targets. In the following study, the modulatory effects of various commercially available and novel cyclohexanols were investigated on recombinant human γ-aminobutyric acid (GABA(A), α(1)β(2)γ(2s)) receptors expressed in Xenopus oocytes, and compared to the modulatory effects on GABA currents observed with exposures to the intravenous anaesthetic agent, propofol. Submaximal EC(20) GABA currents were typically enhanced by co-applications of 3-300 μM cyclohexanols. For instance, at 30 μM 2,6-diisopropylcyclohexanol (a novel compound) GABA responses were increased ~3-fold (although similar enhancements were achieved at 3 μM propofol). As regards rank order for modulation by the cyclohexanol analogues at 30 μM, the % enhancements for 2,6-dimethylcyclohexanol~2,6-diethylcyclohexanol~2,6-diisopropylcyclohexanol~2,6-di-sec-butylcyclohexanol ≫2,6-di-tert-butylcyclohexanol~4-tert-butylcyclohexanol>cyclohexanol~cyclopentanol~2-methylcyclohexanol. We further tested the potencies of the cyclohexanol analogues as general anaesthetics using a tadpole in vivo assay. Both 2,6-diisopropylcyclohexanol and 2,6-dimethylcyclohexanol were effective as anaesthetics with EC(50)s of 14.0 μM and 13.1 μM respectively, while other cyclohexanols with bulkier side chains were less potent. In conclusion, our data indicate that cyclohexanols are both positive modulators of GABA(A) receptors currents and anaesthetics. The positioning and size of the alkyl groups at the 2 and 6 positions on the cyclohexanol ring were critical determinants of activity.
Collapse
Affiliation(s)
- Adam C Hall
- Neuroscience Program, Department of Biological Sciences, Smith College, Northampton, MA 01063, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Sahin K, Sarıpınar E, Yanmaz E, Geçen N. Quantitative bioactivity prediction and pharmacophore identification for benzotriazine derivatives using the electron conformational-genetic algorithm in QSAR. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2011; 22:217-238. [PMID: 21391137 DOI: 10.1080/1062936x.2010.548341] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The electron conformational-genetic algorithm (EC-GA), a sophisticated hybrid approach combining the GA and EC methods, has been employed for a 4D-QSAR procedure to identify the pharmacophore for benzotriazines as sarcoma inhibitors and for quantitative prediction of activity. The calculated geometry and electronic structure parameters of every atom and bond of each molecule are arranged in a matrix described as the electron-conformational matrix of contiguity (ECMC). By comparing the ECMC of one of the most active compounds with other ECMCs we were able to obtain the features of the pharmacophore responsible for the activity, as submatrices of the template known as electron conformational submatrices of activity. The GA was used to select the most important descriptors and to predict the theoretical activity of training and test sets. The predictivity of the model was internally validated. The best QSAR model was selected, having r² = 0.9008, standard error = 0.0510 and cross-validated squared correlation coefficient, q² = 0.8192.
Collapse
Affiliation(s)
- K Sahin
- Bitlis Eren University, Science and Art Faculty, Department of Chemistry, Bitlis, Turkey
| | | | | | | |
Collapse
|
36
|
Yue L, Xie A, Bruzik KS, Frølund B, Qian H, Pepperberg DR. Potentiating action of propofol at GABAA receptors of retinal bipolar cells. Invest Ophthalmol Vis Sci 2011; 52:2497-509. [PMID: 21071744 DOI: 10.1167/iovs.10-5991] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Propofol (2,6-diisopropyl phenol), a widely used systemic anesthetic, is known to potentiate GABA(A) receptor activity in a number of CNS neurons and to produce changes in electroretinographically recorded responses of the retina. However, little is known about propofol's effects on specific retinal neurons. The authors investigated the action of propofol on GABA-elicited membrane current responses of retinal bipolar cells, which have both GABA(A) and GABA(C) receptors. METHODS Single, enzymatically dissociated bipolar cells obtained from rat retina were treated with propofol delivered by brief application in combination with GABA or other pharmacologic agents or as a component of the superfusing medium. RESULTS When applied with GABA at subsaturating concentrations and with TPMPA (a known GABA(C) antagonist), propofol markedly increased the peak amplitude and altered the kinetics of the response. Propofol increased the response elicited by THIP (a GABA(A)-selective agonist), and the response was reduced by bicuculline (a GABA(A) antagonist). The response to 5-methyl I4AA, a GABA(C)-selective agonist, was not enhanced by propofol. Serial brief applications of (GABA + TPMPA + propofol) led to a progressive increase in peak response amplitude and, at higher propofol concentrations, additional changes that included a prolonged time course of response recovery. Pre-exposure of the cell to perfusing propofol typically enhanced the rate of development of potentiation produced by (GABA + TPMPA + propofol) applications. CONCLUSIONS Propofol exerts a marked and selective potentiation on GABA(A) receptors of retinal bipolar cells. The data encourage the use of propofol in future studies of bipolar cell function.
Collapse
Affiliation(s)
- Lan Yue
- Lions of Illinois Eye Research Institute, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | | | | | | | | | | |
Collapse
|
37
|
Ribeiro TL, Copelli M, Caixeta F, Belchior H, Chialvo DR, Nicolelis MAL, Ribeiro S. Spike avalanches exhibit universal dynamics across the sleep-wake cycle. PLoS One 2010; 5:e14129. [PMID: 21152422 PMCID: PMC2994706 DOI: 10.1371/journal.pone.0014129] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 10/27/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Scale-invariant neuronal avalanches have been observed in cell cultures and slices as well as anesthetized and awake brains, suggesting that the brain operates near criticality, i.e. within a narrow margin between avalanche propagation and extinction. In theory, criticality provides many desirable features for the behaving brain, optimizing computational capabilities, information transmission, sensitivity to sensory stimuli and size of memory repertoires. However, a thorough characterization of neuronal avalanches in freely-behaving (FB) animals is still missing, thus raising doubts about their relevance for brain function. METHODOLOGY/PRINCIPAL FINDINGS To address this issue, we employed chronically implanted multielectrode arrays (MEA) to record avalanches of action potentials (spikes) from the cerebral cortex and hippocampus of 14 rats, as they spontaneously traversed the wake-sleep cycle, explored novel objects or were subjected to anesthesia (AN). We then modeled spike avalanches to evaluate the impact of sparse MEA sampling on their statistics. We found that the size distribution of spike avalanches are well fit by lognormal distributions in FB animals, and by truncated power laws in the AN group. FB data surrogation markedly decreases the tail of the distribution, i.e. spike shuffling destroys the largest avalanches. The FB data are also characterized by multiple key features compatible with criticality in the temporal domain, such as 1/f spectra and long-term correlations as measured by detrended fluctuation analysis. These signatures are very stable across waking, slow-wave sleep and rapid-eye-movement sleep, but collapse during anesthesia. Likewise, waiting time distributions obey a single scaling function during all natural behavioral states, but not during anesthesia. Results are equivalent for neuronal ensembles recorded from visual and tactile areas of the cerebral cortex, as well as the hippocampus. CONCLUSIONS/SIGNIFICANCE Altogether, the data provide a comprehensive link between behavior and brain criticality, revealing a unique scale-invariant regime of spike avalanches across all major behaviors.
Collapse
Affiliation(s)
- Tiago L. Ribeiro
- Department of Physics, Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil
| | - Mauro Copelli
- Department of Physics, Federal University of Pernambuco (UFPE), Recife, Pernambuco, Brazil
- Neuroscience Graduate Program, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Fábio Caixeta
- Neuroscience Graduate Program, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
- Edmond and Lily Safra International Institute of Neuroscience of Natal (ELS-IINN), Natal, Rio Grande do Norte, Brazil
| | - Hindiael Belchior
- Edmond and Lily Safra International Institute of Neuroscience of Natal (ELS-IINN), Natal, Rio Grande do Norte, Brazil
- Department of Physiology, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| | - Dante R. Chialvo
- Department of Physiology, Northwestern University, Chicago, Illinois, United States of America
| | - Miguel A. L. Nicolelis
- Neuroscience Graduate Program, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
- Edmond and Lily Safra International Institute of Neuroscience of Natal (ELS-IINN), Natal, Rio Grande do Norte, Brazil
- Department of Neurobiology, Center for Neuroengineering, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- Department of Psychological and Brain Sciences, Duke University, Durham, North Carolina, United States of America
| | - Sidarta Ribeiro
- Neuroscience Graduate Program, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
- Edmond and Lily Safra International Institute of Neuroscience of Natal (ELS-IINN), Natal, Rio Grande do Norte, Brazil
- Department of Physiology, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil
| |
Collapse
|
38
|
Andrade CH, Pasqualoto KFM, Ferreira EI, Hopfinger AJ. 4D-QSAR: perspectives in drug design. Molecules 2010; 15:3281-94. [PMID: 20657478 PMCID: PMC6263259 DOI: 10.3390/molecules15053281] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 03/30/2010] [Accepted: 04/06/2010] [Indexed: 12/05/2022] Open
Abstract
Drug design is a process driven by innovation and technological breakthroughs involving a combination of advanced experimental and computational methods. A broad variety of medicinal chemistry approaches can be used for the identification of hits, generation of leads, as well as to accelerate the optimization of leads into drug candidates. The quantitative structure–activity relationship (QSAR) formalisms are among the most important strategies that can be applied for the successful design new molecules. This review provides a comprehensive review on the evolution and current status of 4D-QSAR, highlighting present challenges and new opportunities in drug design.
Collapse
Affiliation(s)
- Carolina H. Andrade
- Laboratory of Molecular Modeling, Faculty of Pharmacy, Federal University of Goiás, 1ª Av. c/ Praça Universitária, S/N., Goiânia, Goiás, 74605-220, Brazil
- College of Pharmacy, MSC09 5360, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, USA; E-Mail: (A.J.H.)
- Author to whom correspondence should be addressed; E-Mail:
| | - Kerly F. M. Pasqualoto
- Faculty of Pharmaceutical Sciences, Av. Prof. Lineu Prestes, 580, University of Sao Paulo, Sao Paulo, 05508-900, Brazil; E-Mails: (K.F.M.P.); (E.I.F.)
| | - Elizabeth I. Ferreira
- Faculty of Pharmaceutical Sciences, Av. Prof. Lineu Prestes, 580, University of Sao Paulo, Sao Paulo, 05508-900, Brazil; E-Mails: (K.F.M.P.); (E.I.F.)
| | - Anton J. Hopfinger
- College of Pharmacy, MSC09 5360, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, USA; E-Mail: (A.J.H.)
- The Chem21 Group, Inc., 17870 Wilson Drive. Lake Forest, IL 60045, USA
| |
Collapse
|
39
|
Thipnate P, Liu J, Hannongbua S, Hopfinger AJ. 3D pharmacophore mapping using 4D QSAR analysis for the cytotoxicity of lamellarins against human hormone-dependent T47D breast cancer cells. J Chem Inf Model 2009; 49:2312-22. [PMID: 19799437 PMCID: PMC2798151 DOI: 10.1021/ci9002427] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
4D quantitative structure-activity relationship (QSAR) and 3D pharmacophore models were built and investigated for cytotoxicity using a training set of 25 lamellarins against human hormone dependent T47D breast cancer cells. Receptor-independent (RI) 4D QSAR models were first constructed from the exploration of eight possible receptor-binding alignments for the entire training set. Since the training set is small (25 compounds), the generality of the 4D QSAR paradigm was then exploited to devise a strategy to maximize the extraction of binding information from the training set and to also permit virtual screening of diverse lamellarin chemistry. 4D QSAR models were sought for only six of the most potent lamellarins of the training set as well as another subset composed of lamellarins with constrained ranges in molecular weight and lipophilicity. This overall modeling strategy has permitted maximizing 3D pharmacophore information from this small set of structurally complex lamellarins that can be used to drive future analog synthesis and the selection of alternate scaffolds. Overall, it was found that the formation of an intermolecular hydrogen bond and the hydrophobic interactions for substituents on the E ring most modulate the cytotoxicity against T47D breast cancer cells. Hydrophobic substitutions on the F-ring can also enhance cytotoxic potency. A complementary high-throughput virtual screen to the 3D pharmacophore models, a 4D fingerprint QSAR model, was constructed using absolute molecular similarity. This 4D fingerprint virtual high-throughput screen permits a larger range of chemistry diversity to be assayed than with the 4D QSAR models. The optimized 4D QSAR 3D pharmacophore model has a leave-one-out cross-correlation value of xv-r2 = 0.947, while the optimized 4D fingerprint virtual screening model has a value of xv-r2 = 0.719. This work reveals that it is possible to develop significant QSAR, 3D pharmacophore, and virtual screening models for a small set of lamellarins showing cytotoxic behavior in breast cancer screens that can guide future drug development based upon lamellarin chemistry.
Collapse
Affiliation(s)
- Poonsiri Thipnate
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
- Center of Nanotechnology KU, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Jianzhong Liu
- College of Pharmacy, MSC09 5360, 1 University of New Mexico, Albuquerque, New Mexico 87131-000, USA
- The Chem21 Group, Incorporated, 1780 Wilson Drive, Lake Forest, IL 60045
| | - Supa Hannongbua
- Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
- Center of Nanotechnology KU, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - A. J. Hopfinger
- College of Pharmacy, MSC09 5360, 1 University of New Mexico, Albuquerque, New Mexico 87131-000, USA
- The Chem21 Group, Incorporated, 1780 Wilson Drive, Lake Forest, IL 60045
| |
Collapse
|
40
|
Brown ML, Eidam HA, Paige M, Jones PJ, Patel MK. Comparative molecular field analysis and synthetic validation of a hydroxyamide-propofol binding and functional block of neuronal voltage-dependent sodium channels. Bioorg Med Chem 2009; 17:7056-63. [PMID: 19747831 PMCID: PMC3569859 DOI: 10.1016/j.bmc.2008.11.069] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 11/18/2008] [Accepted: 11/20/2008] [Indexed: 11/17/2022]
Abstract
Voltage gated sodium channels represent an important therapeutic target for a number of neurological disorders including epilepsy. Unfortunately, medicinal chemistry strategies for discovering new classes of antagonist for trans-membrane ion channels have been limited to mostly broad screening compound arrays. We have developed new sodium channel antagonist based on a propofol scaffold using the ligand based strategy of comparative molecular field analysis (CoMFA). The resulting CoMFA model was correlated and validated to provide insights into the design of new antagonists and to prioritize synthesis of these new structural analogs (compounds 4 and 5) that satisfied the steric and electrostatic model. Compounds 4 and 5 were evaluated for [(3)H]-batrachotoxinin-A-20-alpha-benzoate ([(3)H]-BTX-B) displacement yielding IC(50)'s of 22 and 5.7 microM, respectively. We further examined the potency of these two compounds to inhibit neuronal sodium currents recorded from cultured hippocampal neurons. At a concentration of 50 microM, compounds 4 and 5 tonically inhibited sodium channels currents by 59+/-7.8% (n=5) and 70+/-7.5% (n=7), respectively. This clearly demonstrates that these compounds functionally antagonize native neuronal sodium channel currents. In summary, we have shown that CoMFA can be effectively used to discover new classes of sodium channel antagonists.
Collapse
Affiliation(s)
- Milton L Brown
- Department of Oncology, 3970 Reservoir Road, Georgetown University Medical Center, Washington, DC 20057, USA.
| | | | | | | | | |
Collapse
|
41
|
Vedula LS, Brannigan G, Economou NJ, Xi J, Hall MA, Liu R, Rossi MJ, Dailey WP, Grasty KC, Klein ML, Eckenhoff RG, Loll PJ. A unitary anesthetic binding site at high resolution. J Biol Chem 2009; 284:24176-84. [PMID: 19605349 DOI: 10.1074/jbc.m109.017814] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABA(A) receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA(A) receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA(A) receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.
Collapse
Affiliation(s)
- L Sangeetha Vedula
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Structure-based shape pharmacophore modeling for the discovery of novel anesthetic compounds. Bioorg Med Chem 2009; 17:5133-8. [DOI: 10.1016/j.bmc.2009.05.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2009] [Revised: 05/18/2009] [Accepted: 05/22/2009] [Indexed: 11/24/2022]
|
43
|
Thippakorn C, Suksrichavalit T, Nantasenamat C, Tantimongcolwat T, Isarankura-Na-Ayudhya C, Naenna T, Prachayasittikul V. Modeling the LPS neutralization activity of anti-endotoxins. Molecules 2009; 14:1869-88. [PMID: 19471207 PMCID: PMC6254205 DOI: 10.3390/molecules14051869] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 05/15/2009] [Accepted: 05/19/2009] [Indexed: 11/23/2022] Open
Abstract
Bacterial lipopolysaccharides (LPS), also known as endotoxins, are major structural components of the outer membrane of Gram-negative bacteria that serve as a barrier and protective shield between them and their surrounding environment. LPS is considered to be a major virulence factor as it strongly stimulates the secretion of pro-inflammatory cytokines which mediate the host immune response and culminating in septic shock. Quantitative structure-activity relationship studies of the LPS neutralization activities of anti-endotoxins were performed using charge and quantum chemical descriptors. Artificial neural network implementing the back-propagation algorithm was selected for the multivariate analysis. The predicted activities from leave-one-out cross-validation were well correlated with the experimental values as observed from the correlation coefficient and root mean square error of 0.930 and 0.162, respectively. Similarly, the external testing set also yielded good predictivity with correlation coefficient and root mean square error of 0.983 and 0.130. The model holds great potential for the rational design of novel and robust compounds with enhanced neutralization activity.
Collapse
Affiliation(s)
- Chadinee Thippakorn
- Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | | | | | | | | | | | | |
Collapse
|
44
|
Sear JW. What makes a molecule an anaesthetic? Studies on the mechanisms of anaesthesia using a physicochemical approach. Br J Anaesth 2009; 103:50-60. [PMID: 19435782 DOI: 10.1093/bja/aep092] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recent studies of mechanisms of anaesthesia have been mainly 'target orientated', investigating the activity of both volatile and i.v. agents at putative sites of action. An alternative approach is one that is 'ligand orientated', focusing on the properties of molecules that define their immobilizing ability and secondly define their potency. The use of conventional descriptors (such as non-polar solubility or the octanol-water partition coefficient [Log P]) are limited in their utility as predictors of potency as they represent three-dimensional molecular properties as a one-dimensional parameter. Using different computer-based molecular modelling methods (molecular similarity studies and comparative molecular field analysis [CoMFA]), we have identified the molecular bases of the activity of structurally diverse anaesthetics, such that they can be described as a single model based on the spatial distribution of molecular bulk and electrostatic potential. The same approach can also be used to model other properties of anaesthetic agents, such as cardiovascular depression. The present data suggest that, for the i.v. agents, it may be difficult to separate immobilizing (anaesthetic) activity and cardiovascular depression within a single molecule.
Collapse
Affiliation(s)
- J W Sear
- Nuffield Department of Anaesthetics, University of Oxford, John Radcliffe Hospital, Oxford, UK.
| |
Collapse
|
45
|
Corvalán NA, Zygadlo JA, García DA. Stereo-selective activity of menthol on GABAAreceptor. Chirality 2009; 21:525-30. [DOI: 10.1002/chir.20631] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
46
|
García DA, Vendrell I, Galofré M, Suñol C. GABA released from cultured cortical neurons influences the modulation of t-[35S]butylbicyclophosphorothionate binding at the GABAA receptor. Eur J Pharmacol 2008; 600:26-31. [DOI: 10.1016/j.ejphar.2008.10.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 09/29/2008] [Accepted: 10/06/2008] [Indexed: 11/28/2022]
|
47
|
Stewart D, Desai R, Cheng Q, Liu A, Forman SA. Tryptophan mutations at azi-etomidate photo-incorporation sites on alpha1 or beta2 subunits enhance GABAA receptor gating and reduce etomidate modulation. Mol Pharmacol 2008; 74:1687-95. [PMID: 18805938 DOI: 10.1124/mol.108.050500] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The potent general anesthetic etomidate produces its effects by enhancing GABA(A) receptor activation. Its photolabel analog [(3)H]azi-etomidate labels residues within transmembrane domains on alpha and beta subunits: alphaMet236 and betaMet286. We hypothesized that these methionines contribute to etomidate sites formed at alpha-beta subunit interfaces and that increasing side-chain bulk and hydrophobicity at either locus would mimic etomidate binding and block etomidate effects. Channel activity was electrophysiologically quantified in alpha(1)beta(2)gamma(2L) receptors with alpha(1)M236W or beta(2)M286W mutations, in both the absence and the presence of etomidate. Measurements included spontaneous activation, GABA EC(50), etomidate agonist potentiation, etomidate direct activation, and rapid macrocurrent kinetics. Both alpha(1)M236W and beta(2)M286W mutations induced spontaneous channel opening, lowered GABA EC(50), increased maximal GABA efficacy, and slowed current deactivation, mimicking effects of etomidate on alpha(1)beta(2)gamma(2L) channels. These changes were larger with alpha(1)M236W than with beta(2)M286W. Etomidate (3.2 muM) reduced GABA EC(50) much less in alpha(1)M236Wbeta(2)gamma(2L) receptors (2-fold) than in wild type (23-fold). However, etomidate was more potent and efficacious in directly activating alpha(1)M236Wbeta(2)gamma(2L) compared with wild type. In alpha(1)beta(2)M286Wgamma(2L) receptors, etomidate induced neither agonist-potentiation nor direct channel activation. These results support the hypothesis that alpha(1)Met236 and beta(2)Met286 are within etomidate sites that allosterically link to channel gating. Although alpha(1)M236W produced the larger impact on channel gating, beta(2)M286W produced more profound changes in etomidate sensitivity, suggesting a dominant role in drug binding. 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.
Collapse
Affiliation(s)
- Deirdre Stewart
- Beecher/Mallincrodt Labs, Department of Anesthesia & Critical Care, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
| | | | | | | | | |
Collapse
|
48
|
Watt EE, Betts BA, Kotey FO, Humbert DJ, Griffith TN, Kelly EW, Veneskey KC, Gill N, Rowan KC, Jenkins A, Hall AC. Menthol shares general anesthetic activity and sites of action on the GABAA receptor with the intravenous agent, propofol. Eur J Pharmacol 2008; 590:120-6. [DOI: 10.1016/j.ejphar.2008.06.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 05/16/2008] [Accepted: 06/02/2008] [Indexed: 11/16/2022]
|
49
|
Romeiro NC, Albuquerque MG, de Alencastro RB, Ravi M, Hopfinger AJ. Construction of 4D-QSAR models for use in the design of novel p38-MAPK inhibitors. J Comput Aided Mol Des 2008; 19:385-400. [PMID: 16231199 DOI: 10.1007/s10822-005-7927-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Accepted: 05/22/2005] [Indexed: 12/11/2022]
Abstract
The p38-mitogen-activated protein kinase (p38-MAPK) plays a key role in lipopolysaccharide-induced tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) release during the inflammatory process, emerging as an attractive target for new anti-inflammatory agents. Four-dimensional quantitative structure-activity relationship (4D-QSAR) analysis [Hopfinger et al., J. Am. Chem. Soc., 119 (1997) 10509] was applied to a series of 33 (a training set of 28 and a test set of 5) pyridinyl-imidazole and pyrimidinyl-imidazole inhibitors of p38-MAPK, with IC50 ranging from 0.11 to 2100 nM [Liverton et al., J. Med. Chem., 42 (1999) 2180]. Five thousand conformations of each analogue were sampled from a molecular dynamics simulation (MDS) during 50 ps at a constant temperature of 303 K. Each conformation was placed in a 2 angstroms grid cell lattice for each of three trial alignments. 4D-QSAR models were constructed by genetic algorithm (GA) optimization and partial least squares (PLS) fitting, and evaluated by leave-one-out cross-validation technique. In the best models, with three to six terms, the adjusted cross-validated squared correlation coefficients, Q2adj, ranged from 0.67 to 0.85. Model D (Q2adj = 0.84) was identified as the most robust model from alignment 1, and it is representative of the other best models. This model encompasses new molecular regions as containing pharmacophore sites, such as the amino-benzyl moiety of pyrimidine analogs and the N1-substituent in the imidazole ring. These regions of the ligands should be further explored to identify better anti-inflammatory inhibitors of p38-MAPK.
Collapse
Affiliation(s)
- Nelilma Correia Romeiro
- Departamento de Química Orgânica, Laboratório de Modelagem Molecular (LabMMol), Instituto de Química, Centro de Tecnologia, Bloco A, Ilha do Fundão, Universidade Federal do Rio de Janeiro, 21949-900, Rio de Janeiro, RJ, Brasil.
| | | | | | | | | |
Collapse
|
50
|
Abstract
The advent of therapeutic strategies aimed at targeting specific macromolecular components of deregulated signaling pathways associated with particular disease states has given rise to the idea that it should be possible to design ligands as drug candidates to these targets from first principles. This concept has been beckoning for a long time but structure-based ligand design only became feasible once it was possible to determine the 3-D structures of molecular targets at atomic resolution. However, structure-based design turned out to be difficult, chiefly because under physiological conditions both receptors and ligands are not static but they behave dynamically. While it is possible to design ligands with high steric and electronic complementarity to a receptor site, it is always uncertain how biologically relevant the assumed conformations of both ligand and receptor actually are. The fact that it remains beyond our current abilities to predict with sufficient accuracy the affinity between hypothetical ligand and receptor poses is in part connected with this problem and continues to confound the reliable prediction of drug-like ligands for therapeutic targets. Nevertheless, significant progress has been made and so-called virtual screening methods that use computational methods to dock candidate ligands into receptor sites and to score the resulting complexes are now used routinely as one of the components in drug discovery screening campaigns. Here an overview is given of the underlying principles, implementations, and applications of structure-guided computational design technologies. Although the emphasis is on receptor-based strategies, mention will also be made of some of the more established ligand-based approaches, such as similarity analyses and quantitative structure-activity relationship methods.
Collapse
Affiliation(s)
- Peter M Fischer
- Centre for Biomolecular Sciences and School of Pharmacy, University of Nottingham, University Park, Nottingham, UK.
| |
Collapse
|