1
|
Liu J, Gui Y, Rao J, Sun J, Wang G, Ren Q, Qu N, Niu B, Chen Z, Sheng X, Wang Y, Zheng M, Li X. In silico off-target profiling for enhanced drug safety assessment. Acta Pharm Sin B 2024; 14:2927-2941. [PMID: 39027254 PMCID: PMC11252485 DOI: 10.1016/j.apsb.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/21/2024] [Accepted: 02/29/2024] [Indexed: 07/20/2024] Open
Abstract
Ensuring drug safety in the early stages of drug development is crucial to avoid costly failures in subsequent phases. However, the economic burden associated with detecting drug off-targets and potential side effects through in vitro safety screening and animal testing is substantial. Drug off-target interactions, along with the adverse drug reactions they induce, are significant factors affecting drug safety. To assess the liability of candidate drugs, we developed an artificial intelligence model for the precise prediction of compound off-target interactions, leveraging multi-task graph neural networks. The outcomes of off-target predictions can serve as representations for compounds, enabling the differentiation of drugs under various ATC codes and the classification of compound toxicity. Furthermore, the predicted off-target profiles are employed in adverse drug reaction (ADR) enrichment analysis, facilitating the inference of potential ADRs for a drug. Using the withdrawn drug Pergolide as an example, we elucidate the mechanisms underlying ADRs at the target level, contributing to the exploration of the potential clinical relevance of newly predicted off-target interactions. Overall, our work facilitates the early assessment of compound safety/toxicity based on off-target identification, deduces potential ADRs of drugs, and ultimately promotes the secure development of drugs.
Collapse
Affiliation(s)
- Jin Liu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
| | - Yike Gui
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Jingxin Rao
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingjing Sun
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gang Wang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qun Ren
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Ning Qu
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Buying Niu
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyi Chen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, Hangzhou 330106, China
| | - Xia Sheng
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yitian Wang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingyue Zheng
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Nanjing University of Chinese Medicine, Nanjing 210023, China
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, Hangzhou 330106, China
| | - Xutong Li
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
2
|
Ortore G, Orlandini E, Betti L, Giannaccini G, Mazzoni MR, Camodeca C, Nencetti S. Focus on Human Monoamine Transporter Selectivity. New Human DAT and NET Models, Experimental Validation, and SERT Affinity Exploration. ACS Chem Neurosci 2020; 11:3214-3232. [PMID: 32991141 PMCID: PMC8015229 DOI: 10.1021/acschemneuro.0c00304] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
![]()
The most commonly used antidepressant
drugs are the serotonin transporter
inhibitors. Their effects depend strongly on the selectivity for a
single monoamine transporter compared to other amine transporters
or receptors, and the selectivity is roughly influenced by the spatial
protein structure. Here, we provide a computational study on three
human monoamine transporters, i.e., DAT, NET, and SERT. Starting from
the construction of hDAT and hNET models, whose three-dimensional
structure is unknown, and the prediction of the binding pose for 19
known inhibitors, 3D-QSAR models of three human transporters were
built. The training set variability, which was high in structure and
activity profile, was validated using a set of in-house compounds.
Results concern more than one aspect. First of all, hDAT and hNET
three-dimensional structures were built, validated, and compared to
the hSERT one; second, the computational study highlighted the differences
in binding site arrangement statistically correlated to inhibitor
selectivity; third, the profiling of new inhibitors pointed out a
conservation of the inhibitory activity trend between rabbit and human
SERT with a difference of about 1 order of magnitude; fourth, binding
and functional studies confirmed 4-(benzyloxy)-4-phenylpiperidine 20a–d and 21a–d as potent SERT
inhibitors. In particular, one of the compounds (compound 20b) revealed a higher affinity for SERT than paroxetine in human platelets.
Collapse
Affiliation(s)
- Gabriella Ortore
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Elisabetta Orlandini
- Research Center “E. Piaggio”, University of Pisa, Pisa 56122, Italy
- Department of Earth Sciences, University of Pisa, Via Santa Maria 53-55, 56100 Pisa, Italy
| | - Laura Betti
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Gino Giannaccini
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Maria Rosa Mazzoni
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Caterina Camodeca
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Susanna Nencetti
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| |
Collapse
|
3
|
Djikic T, Martí Y, Spyrakis F, Lau T, Benedetti P, Davey G, Schloss P, Yelekci K. Human dopamine transporter: the first implementation of a combined in silico/in vitro approach revealing the substrate and inhibitor specificities. J Biomol Struct Dyn 2018; 37:291-306. [PMID: 29334320 DOI: 10.1080/07391102.2018.1426044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Parkinson's disease (PD) is characterized by the loss of dopamine-generating neurons in the substantia nigra and corpus striatum. Current treatments alleviate PD symptoms rather than exerting neuroprotective effect on dopaminergic neurons. New drugs targeting the dopaminergic neurons by specific uptake through the human dopamine transporter (hDAT) could represent a viable strategy for establishing selective neuroprotection. Molecules able to increase the bioactive amount of extracellular dopamine, thereby enhancing and compensating a loss of dopaminergic neurotransmission, and to exert neuroprotective response because of their accumulation in the cytoplasm, are required. By means of homology modeling, molecular docking, and molecular dynamics simulations, we have generated 3D structure models of hDAT in complex with substrate and inhibitors. Our results clearly reveal differences in binding affinity of these compounds to the hDAT in the open and closed conformations, critical for future drug design. The established in silico approach allowed the identification of promising substrate compounds that were subsequently analyzed for their efficiency in inhibiting hDAT-dependent fluorescent substrate uptake, through in vitro live cell imaging experiments. Taken together, our work presents the first implementation of a combined in silico/in vitro approach enabling the selection of promising dopaminergic neuron-specific substrates.
Collapse
Affiliation(s)
- Teodora Djikic
- a Department of Bioinformatics and Genetics , Kadir Has University , Cibali campus, Fatih 34083 , Istanbul , Turkey
| | - Yasmina Martí
- b Hector Institute for Translational Brain Research, Central Institute of Mental Health, Medical Faculty Mannheim , Heidelberg University , Mannheim J5, 68159 , Germany.,f Biochemical Laboratory, Psychiatry and Psychotherapy Department, Central Institute of Mental Health, Medical Faculty Mannheim , Heidelberg University , Mannheim J5, 68159 , Germany
| | - Francesca Spyrakis
- c Department of Drug Science and Technology , University of Turin , via P. Giuria 9, Turin 10125 , Italy
| | - Thorsten Lau
- b Hector Institute for Translational Brain Research, Central Institute of Mental Health, Medical Faculty Mannheim , Heidelberg University , Mannheim J5, 68159 , Germany
| | - Paolo Benedetti
- d Department of Chemistry, Biology and Biotechnology , University of Perugia , via Elce di sotto 8, Perugia 06123 , Italy
| | - Gavin Davey
- e School of Biochemistry and Immunology , Trinity College Dublin , Dublin 2, Ireland
| | - Patrick Schloss
- f Biochemical Laboratory, Psychiatry and Psychotherapy Department, Central Institute of Mental Health, Medical Faculty Mannheim , Heidelberg University , Mannheim J5, 68159 , Germany
| | - Kemal Yelekci
- a Department of Bioinformatics and Genetics , Kadir Has University , Cibali campus, Fatih 34083 , Istanbul , Turkey
| |
Collapse
|
4
|
Immadisetty K, Geffert LM, Surratt CK, Madura JD. New design strategies for antidepressant drugs. Expert Opin Drug Discov 2013; 8:1399-414. [PMID: 23991860 DOI: 10.1517/17460441.2013.830102] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION In spite of research efforts spanning six decades, the most prominent antidepressant drugs to date still carry several adverse effects, often serious enough to warrant discontinuation of the drug. Molecular mechanisms of depression are now better understood such that some of the specific receptors responsible can be targeted for activation or inhibition. This advance, coupled with the recent availability of crystal structures of relevant drug targets or their homologs, has opened the door for new antidepressant therapeutic compounds. AREAS COVERED The authors review the evolution of monoamine-based antidepressant drugs, up to the selective serotonin reuptake inhibitors (SSRIs). The authors discuss classic and contemporary antidepressant drug design strategies, with a focus on virtual screening and fragment-based drug design methods. Furthermore, they discuss the recent advancements in the understanding of the serotonin transporter (SERT) structure/function relationship in the context of recognition of SSRIs and outline a strategy for the use of computational approaches in producing new SSRI lead compounds. EXPERT OPINION The authors suggest that given the long-awaited availability of credible three-dimensional structures for the SERT and related monoamine transporter proteins, cutting-edge computational methods should be the linchpin of future drug discovery efforts regarding monoamine-based antidepressant lead compounds. Because these transporter inhibitors cause a ubiquitous increase in extraneuronal neurotransmitter levels leading to side and adverse therapeutic effects, the drug discovery should extend to appropriate manipulation of the 'downstream' receptors affected by the neurotransmitter boost. Efficient use of new computational strategies will accelerate the drug discovery process and reduce its economic burden.
Collapse
Affiliation(s)
- Kalyan Immadisetty
- Duquesne University, Center for Computational Sciences, Department of Chemistry and Biochemistry , 600 Forbes Ave, 308 Mellon Hall, Pittsburgh, PA 15282 , USA +1 412 396 4129 ; +1 412 396 5683 ;
| | | | | | | |
Collapse
|
5
|
Abstract
Neurotransmitter:sodium symporters (NSSs) play a critical role in signaling by reuptake of neurotransmitters. Eukaryotic NSSs are chloride-dependent, whereas prokaryotic NSS homologs like LeuT are chloride-independent but contain an acidic residue (Glu290 in LeuT) at a site where eukaryotic NSSs have a serine. The LeuT-E290S mutant displays chloride-dependent activity. We show that, in LeuT-E290S cocrystallized with bromide or chloride, the anion is coordinated by side chain hydroxyls from Tyr47, Ser290, and Thr254 and the side chain amide of Gln250. The bound anion and the nearby sodium ion in the Na1 site organize a connection between their coordinating residues and the extracellular gate of LeuT through a continuous H-bond network. The specific insights from the structures, combined with results from substrate binding studies and molecular dynamics simulations, reveal an anion-dependent occlusion mechanism for NSS and shed light on the functional role of chloride binding.
Collapse
|
6
|
Manepalli S, Surratt CK, Madura JD, Nolan TL. Monoamine transporter structure, function, dynamics, and drug discovery: a computational perspective. AAPS JOURNAL 2012; 14:820-31. [PMID: 22918625 DOI: 10.1208/s12248-012-9391-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 07/09/2012] [Indexed: 11/30/2022]
Abstract
With the breakthrough crystallization of the bacterial leucine transporter protein LeuT, the first available X-ray structure for the neurotransmitter/sodium symporter family, development of 3-D computational models is suddenly essential for structure-function studies on the plasmalemmal monoamine transporters (MATs). LeuT-based MAT models have been used to guide elucidation of substrate and inhibitor binding pockets, and molecular dynamics simulations using these models are providing insight into conformations involved in the substrate translocation cycle. With credible MAT models finally in hand, structure-based virtual screening for novel ligands is yielding lead compounds toward the development of new medications for psychostimulant dependence, attention deficit hyperactivity, depression, anxiety, schizophrenia, and other disorders associated with dopamine, norepinephrine, or serotonin dysregulation.
Collapse
Affiliation(s)
- Sankar Manepalli
- Department of Chemistry and Biochemistry, Center for Computational Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | | | | | | |
Collapse
|
7
|
Kristensen AS, Andersen J, Jørgensen TN, Sørensen L, Eriksen J, Loland CJ, Strømgaard K, Gether U. SLC6 neurotransmitter transporters: structure, function, and regulation. Pharmacol Rev 2011; 63:585-640. [PMID: 21752877 DOI: 10.1124/pr.108.000869] [Citation(s) in RCA: 591] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The neurotransmitter transporters (NTTs) belonging to the solute carrier 6 (SLC6) gene family (also referred to as the neurotransmitter-sodium-symporter family or Na(+)/Cl(-)-dependent transporters) comprise a group of nine sodium- and chloride-dependent plasma membrane transporters for the monoamine neurotransmitters serotonin (5-hydroxytryptamine), dopamine, and norepinephrine, and the amino acid neurotransmitters GABA and glycine. The SLC6 NTTs are widely expressed in the mammalian brain and play an essential role in regulating neurotransmitter signaling and homeostasis by mediating uptake of released neurotransmitters from the extracellular space into neurons and glial cells. The transporters are targets for a wide range of therapeutic drugs used in treatment of psychiatric diseases, including major depression, anxiety disorders, attention deficit hyperactivity disorder and epilepsy. Furthermore, psychostimulants such as cocaine and amphetamines have the SLC6 NTTs as primary targets. Beginning with the determination of a high-resolution structure of a prokaryotic homolog of the mammalian SLC6 transporters in 2005, the understanding of the molecular structure, function, and pharmacology of these proteins has advanced rapidly. Furthermore, intensive efforts have been directed toward understanding the molecular and cellular mechanisms involved in regulation of the activity of this important class of transporters, leading to new methodological developments and important insights. This review provides an update of these advances and their implications for the current understanding of the SLC6 NTTs.
Collapse
Affiliation(s)
- Anders S Kristensen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Nencetti S, Mazzoni MR, Ortore G, Lapucci A, Giuntini J, Orlandini E, Banti I, Nuti E, Lucacchini A, Giannaccini G, Rossello A. Synthesis, molecular docking and binding studies of selective serotonin transporter inhibitors. Eur J Med Chem 2011; 46:825-34. [DOI: 10.1016/j.ejmech.2010.12.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 12/14/2010] [Accepted: 12/14/2010] [Indexed: 11/27/2022]
|
9
|
Lin Z, Canales JJ, Björgvinsson T, Thomsen MM, Qu H, Liu QR, Torres GE, Caine SB. Monoamine transporters: vulnerable and vital doorkeepers. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 98:1-46. [PMID: 21199769 PMCID: PMC3321928 DOI: 10.1016/b978-0-12-385506-0.00001-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Transporters of dopamine, serotonin, and norepinephrine have been empirically used as medication targets for several mental illnesses in the last decades. These protein-targeted medications are effective only for subpopulations of patients with transporter-related brain disorders. Since the cDNA clonings in early 1990s, molecular studies of these transporters have revealed a wealth of information about the transporters' structure-activity relationship (SAR), neuropharmacology, cell biology, biochemistry, pharmacogenetics, and the diseases related to the human genes encoding these transporters among related regulators. Such new information creates a unique opportunity to develop transporter-specific medications based on SAR, mRNA, DNA, and perhaps transporter trafficking regulation for a number of highly relevant diseases including substance abuse, depression, schizophrenia, and Parkinson's disease.
Collapse
Affiliation(s)
- Zhicheng Lin
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
| | - Juan J. Canales
- Department of Psychology, Behavioural Neuroscience, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Thröstur Björgvinsson
- Behavioral Health Partial Hospital and Psychology Internship Programs, McLean Hospital/Harvard Medical School, Belmont, MA 02478, USA
| | - Morgane M. Thomsen
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
| | - Hong Qu
- Center for Bioinformatics, National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University. Beijing, 100871 China
| | - Qing-Rong Liu
- Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, 251 Bayview Boulevard, Baltimore, MD 21224, USA
| | - Gonzalo E. Torres
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - S. Barak Caine
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
| |
Collapse
|
10
|
Torres-Altoro MI, Kuntz CP, Nichols DE, Barker EL. Structural analysis of the extracellular entrance to the serotonin transporter permeation pathway. J Biol Chem 2010; 285:15369-15379. [PMID: 20304925 DOI: 10.1074/jbc.m109.088138] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neurotransmitter transporters are responsible for removal of biogenic amine neurotransmitters after release into the synapse. These transporters are the targets for many clinically relevant drugs, such as antidepressants and psychostimulants. A high resolution crystal structure for the monoamine transporters has yet to be solved. We have developed a homology model for the serotonin transporter (SERT) based on the crystal structure of the leucine transporter (LeuT(Aa)) from Aquifex aeolicus. The objective of the present studies is to identify the structural determinants forming the entrance to the substrate permeation pathway based on predictions from the SERT homology model. Using the substituted cysteine accessibility method, we identified residues predicted to reside at the entrance to the substrate permeation pathway that were reactive with methanethiosulfonate (MTS) reagents. Of these residues, Gln(332) in transmembrane helix (TMH) VI was protected against MTS inactivation in the presence of serotonin. Surprisingly, the reactivity of Gln(332) to MTS reagents was enhanced in the presence of cocaine. Bifunctional MTS cross-linkers also were used to examine the distances between helices predicted to form the entrance into the substrate and ion permeation pathway. Our studies suggest that substrate and ligand binding may induce conformational shifts in TMH I and/or VI, providing new opportunities to refine existing homology models of SERT and related monoamine transporters.
Collapse
Affiliation(s)
- Melissa I Torres-Altoro
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University School of Pharmacy and Pharmaceutical Sciences, West Lafayette, Indiana 47907-2091
| | - Charles P Kuntz
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University School of Pharmacy and Pharmaceutical Sciences, West Lafayette, Indiana 47907-2091
| | - David E Nichols
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University School of Pharmacy and Pharmaceutical Sciences, West Lafayette, Indiana 47907-2091
| | - Eric L Barker
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University School of Pharmacy and Pharmaceutical Sciences, West Lafayette, Indiana 47907-2091.
| |
Collapse
|
11
|
Wang CIA, Lewis RJ. Emerging structure-function relationships defining monoamine NSS transporter substrate and ligand affinity. Biochem Pharmacol 2009; 79:1083-91. [PMID: 19954741 DOI: 10.1016/j.bcp.2009.11.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/16/2009] [Accepted: 11/23/2009] [Indexed: 11/15/2022]
Abstract
Monoamine transporters are a group of transmembrane neurotransmitter sodium symporter (NSS) transporters that play a crucial role in regulating biogenic monoamine concentrations at peripheral and central synapses. Given the key role played by serotonin, dopamine and noradrenaline in addictive and disease states, structure-function studies have been conducted to help guide the development of improved central nervous system therapeutics. Extensive pharmacological, immunological and biochemical studies, in conjunction with three-dimensional homology modeling, have been performed to structurally and functionally characterise the monoamine transporter substrate permeation pathway, substrate selectivity, and binding sites for ions, substrates and inhibitors at the molecular level. However, only recently has it been possible to start to construct an accurate molecular interaction network for the monoamine transporters and their corresponding substrates and inhibitors. Crystal structures of Aquifex aeolicus leucine transporter (LeuT(Aa)), a homologous protein to monoamine transporters that has been experimentally demonstrated to share similar structural folds with monoamine transporters, have been determined in complex with amino acids and inhibitors. The molecular interactions of leucine and tricyclic antidepressants (TCA) has supported many of the predictions based on the mutational studies. Models constructed from LeuT(Aa) are now allowing a rational approach to further clarify the molecular determinants of NSS transporter-ligand complexes, and potentially the ability to better manipulate drug specificity and affinity. In this review, we compare the structure-function relationships of other SLC6 NSS family transporters with monoamine transporters, and discuss possible mechanisms involved in substrate binding and transport, and modes of inhibition by TCAs.
Collapse
Affiliation(s)
- Ching-I Anderson Wang
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Australia
| | | |
Collapse
|
12
|
Baliova M, Knab A, Franekova V, Jursky F. Modification of the cytosolic regions of GABA transporter GAT1 by calpain. Neurochem Int 2009; 55:288-94. [PMID: 19576516 DOI: 10.1016/j.neuint.2009.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 02/20/2009] [Accepted: 03/18/2009] [Indexed: 11/18/2022]
Abstract
Cytosolic regions of sodium dependent neurotransmitter transporters regulate their surface density and transporting function by interconnecting themselves with intracellular signaling pathways. Here we show that calpain activation in rat brain synaptosomes leads to cleavage of both N- and C-terminal regions of GABA transporter GAT1. In the C-terminal region, calpain removes a short segment of amino acids involved in binding of GAT1 to a high-density PDZ anchoring matrix. Using a protein pull-down assay, we found that C-terminal truncation of GAT1 results in modification of its interacting proteome in vitro. Results indicate that calpain activation/inhibition in GABAergic terminals may influence the scaffolding and surface expression of GABA transporter GAT1 under normal conditions or imbalance GAT1-mediated GABAergic transmission under pathological states.
Collapse
Affiliation(s)
- Martina Baliova
- Laboratory of Neurobiology, Institute of Molecular Biology, Slovak Academy of Sciences, Dubravska cesta 21, 84251 Bratislava, Slovakia
| | | | | | | |
Collapse
|
13
|
Structure and localisation of drug binding sites on neurotransmitter transporters. J Mol Model 2009; 15:1155-64. [PMID: 19238460 DOI: 10.1007/s00894-009-0478-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 01/28/2009] [Indexed: 10/21/2022]
Abstract
The dopamine (DAT), serotontin (SERT) and noradrenalin (NET) transporters are molecular targets for different classes of psychotropic drugs. The crystal structure of Aquifex aeolicus LeuT(Aa) was used as a template for molecular modeling of DAT, SERT and NET, and two putative drug binding sites (pocket 1 and 2) in each transporter were identified. Cocaine was docked into binding pocket 1 of DAT, corresponding to the leucine binding site in LeuT(Aa), which involved transmembrane helices (TMHs) 1, 3, 6 and 8. Clomipramine was docked into binding pocket 2 of DAT, involving TMHs 1, 3, 6, 10 and 11, and extracellular loops 4 and 6, corresponding to the clomipramine binding site in a crystal structure of a LeuT(Aa)-clomipramine complex. The structures of the proposed cocaine- and tricyclic antidepressant-binding sites may be of particular interest for the design of novel DAT interacting ligands.
Collapse
|
14
|
Kaufmann KW, Dawson ES, Henry LK, Field JR, Blakely RD, Meiler J. Structural determinants of species-selective substrate recognition in human and Drosophila serotonin transporters revealed through computational docking studies. Proteins 2009; 74:630-42. [PMID: 18704946 DOI: 10.1002/prot.22178] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To identify potential determinants of substrate selectivity in serotonin (5-HT) transporters (SERT), models of human and Drosophila serotonin transporters (hSERT, dSERT) were built based on the leucine transporter (LeuT(Aa)) structure reported by Yamashita et al. (Nature 2005;437:215-223), PBDID 2A65. Although the overall amino acid identity between SERTs and the LeuT(Aa) is only 17%, it increases to above 50% in the first shell of the putative 5-HT binding site, allowing de novo computational docking of tryptamine derivatives in atomic detail. Comparison of hSERT and dSERT complexed with substrates pinpoints likely structural determinants for substrate binding. Forgoing the use of experimental transport and binding data of tryptamine derivatives for construction of these models enables us to critically assess and validate their predictive power: A single 5-HT binding mode was identified that retains the amine placement observed in the LeuT(Aa) structure, matches site-directed mutagenesis and substituted cysteine accessibility method (SCAM) data, complies with support vector machine derived relations activity relations, and predicts computational binding energies for 5-HT analogs with a significant correlation coefficient (R = 0.72). This binding mode places 5-HT deep in the binding pocket of the SERT with the 5-position near residue hSERT A169/dSERT D164 in transmembrane helix 3, the indole nitrogen next to residue Y176/Y171, and the ethylamine tail under residues F335/F327 and S336/S328 within 4 A of residue D98. Our studies identify a number of potential contacts whose contribution to substrate binding and transport was previously unsuspected.
Collapse
Affiliation(s)
- Kristian W Kaufmann
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235-1822, USA
| | | | | | | | | | | |
Collapse
|
15
|
Aparoy P, Leela T, Reddy RN, Reddanna P. Computational analysis of R and S isoforms of 12-lipoxygenases: homology modeling and docking studies. J Mol Graph Model 2008; 27:744-50. [PMID: 19147381 DOI: 10.1016/j.jmgm.2008.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2008] [Revised: 11/18/2008] [Accepted: 11/19/2008] [Indexed: 11/19/2022]
Abstract
The present study is aimed at predicting human 12R-LOX structure by constructing a homology model. Based upon Blast results, rabbit reticulocyte 15-lipoxygenase 1LOX (protein data bank) was considered as a template for homology modeling. The 3D model was generated with Modeler in InsightII and further refined using AMBER. Further to understand the relationship of protein structure with stereo specificity, a comparative analysis of 12R-LOX model was done with that of 12S-LOX homology model to identify differences in the binding site topology and interacting residues. The large insertion of 31-aa seen in 12R-LOX is located beyond the N-terminal barrel and is accommodated on the outside of the protein without disruption of the overall tertiary structure. The 31-aa region includes SH3 domain binding PXXP motif, seven prolines and five arginines. The docking of the substrate, arachidonic acid was also performed. Our results show that the Gly441 and substrate orientation within the active site play an important role in stereo specificity of 12R-LOX.
Collapse
Affiliation(s)
- P Aparoy
- School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | | | | | | |
Collapse
|
16
|
Martin RS, Henningsen RA, Suen A, Apparsundaram S, Leung B, Jia Z, Kondru RK, Milla ME. Kinetic and thermodynamic assessment of binding of serotonin transporter inhibitors. J Pharmacol Exp Ther 2008; 327:991-1000. [PMID: 18801948 DOI: 10.1124/jpet.108.142307] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Several serotonin reuptake inhibitors are in clinical use for treatment of depression and anxiety disorders. However, to date, reported pharmacological differentiation of these ligands has focused mainly on their equilibrium binding affinities for the serotonin transporter. This study takes a new look at antidepressant binding modes using radioligand binding assays with [(3)H]S-citalopram to determine equilibrium and kinetic rate constants across multiple temperatures. The observed dissociation rate constants at 26 degrees C fall into a narrow range for all molecules. Conversely, association rate constants generally decreased with increasing equilibrium binding affinities. Consistent with this, the measured activation energy for S-citalopram association was relatively large (19.5 kcal . mol(-1)), suggesting conformational change upon ligand binding. For most of the drugs, including citalopram, the enthalpy (DeltaH(O)) and entropy (-TDeltaS(O)) contributions to reaction energetics were determined by van't Hoff analyses to be roughly equivalent (25-75% DeltaG(O)) and to correlate (positively for enthalpy) with the polar surface area of the drug. However, the binding of the drug fluvoxamine was predominantly entropically driven. When these data are considered in the context of the physicochemical properties of these ligands, two distinct binding modes can be proposed. The citalopram-type binding mode probably uses a polar binding pocket that allows charged or polar interactions between ligand and receptor with comparatively small loss in enthalpy due to dehydration. The fluvoxamine-type binding mode is fueled by energy released upon burying hydrophobic ligand moieties into a binding pocket that is flexible enough to suffer minimal loss in entropy from conformational constraint.
Collapse
Affiliation(s)
- Renee S Martin
- Departments of Biochemical Pharmacology, Roche Pharmaceuticals, Palo Alto CA 94304, USA.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Jørgensen AM, Tagmose L, Jørgensen AMM, Bøgesø KP, Peters GH. Molecular dynamics simulations of Na+/Cl(-)-dependent neurotransmitter transporters in a membrane-aqueous system. ChemMedChem 2008; 2:827-40. [PMID: 17436258 DOI: 10.1002/cmdc.200600243] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We have performed molecular dynamics simulations of a homology model of the human serotonin transporter (hSERT) in a membrane environment and in complex with either the natural substrate 5-HT or the selective serotonin reuptake inhibitor escitalopram. We have also included a transporter homologue, the Aquifex aeolicus leucine transporter (LeuT), in our study to evaluate the applicability of a simple and computationally attractive membrane system. Fluctuations in LeuT extracted from simulations are in good agreement with crystallographic B factors. Furthermore, key interactions identified in the X-ray structure of LeuT are maintained throughout the simulations indicating that our simple membrane system is suitable for studying the transmembrane protein hSERT in complex with 5-HT or escitalopram. For these transporter complexes, only relatively small fluctuations are observed in the ligand-binding cleft. Specific interactions responsible for ligand recognition, are identified in the hSERT-5HT and hSERT-escitalopram complexes. Our findings are in good agreement with predictions from mutagenesis studies.
Collapse
Affiliation(s)
- Anne Marie Jørgensen
- MEMPHYS-Center for Biomembrane Physics, Department of Chemistry, Technical University of Denmark, Building 206, 2800 Kgs. Lyngby, Denmark
| | | | | | | | | |
Collapse
|
18
|
Jarończyk M, Chilmonczyk Z, Mazurek AP, Nowak G, Ravna AW, Kristiansen K, Sylte I. The molecular interactions of buspirone analogues with the serotonin transporter. Bioorg Med Chem 2008; 16:9283-94. [PMID: 18812261 DOI: 10.1016/j.bmc.2008.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Revised: 08/26/2008] [Accepted: 09/02/2008] [Indexed: 11/18/2022]
Abstract
A major problem with the selective serotonin reuptake inhibitors (SSRIs) is the delayed onset of action. A reason for that may be that the initial SSRI-induced increase in serotonin levels activates somatodendritic 5-HT(1A) autoreceptors, causing a decrease in serotonin release in major forebrain areas. It has been suggested that compounds combining inhibition of the serotonin transport protein with antagonistic effects on the 5-HT(1A) receptor will shorten the onset time. The anxiolytic drug buspirone is known as 5-HT(1A) partial agonist. In the present work, we are studying the inhibition of the serotonin transporter protein by a series of buspirone analogues by molecular modelling and by experimental affinity measurements. Models of the transporter protein were constructed using the crystal structure of the Escherichia coli major facilitator family transporter-LacY and the X-ray structure of the neurotransmitter symporter family (NSS) transporter-LeuT(Aa) as templates. The buspirone analogues were docked into both SERT models and the interactions with amino acids within the protein were analyzed. Two putative binding sites were identified on the LeuT(Aa) based model, one suggested to be a high-affinity site, and the other suggested to be a low-affinity binding site. Molecular dynamic simulations of the LacY based model in complex with ligands did not induce a helical architecture of the LacY based model into an arrangement more similar to that of the LeuT(Aa) based model.
Collapse
|
19
|
Torres-Altoro MI, White KJ, Rodríguez GJ, Nichols DE, Barker EL. Helix XI contributes to the entrance of the serotonin transporter permeation pathway. Protein Sci 2008; 17:1761-70. [PMID: 18628241 DOI: 10.1110/ps.036749.108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The sodium-dependent transporters for dopamine, norepinephrine, and serotonin that regulate neurotransmission, also translocate the neurotoxin 1-methyl-4-phenylpyridinium (MPP(+)). Previous studies implicated residues in transmembrane helix (TMH) XI of DAT as important sites for MPP(+) transport. We examined the importance of TMH XI residues F551 and F556 for MPP(+) translocation by human SERT. Mutations at hSERT F556, but not F551, reduced both 5-HT and MPP(+) transport compared to wild type. However, F556S/hSERT showed a reduction in surface expression explaining the decrease of transport activity for 5-HT, but did not account for the decrease in MPP(+) transport observed. Cysteine mutants at those positions confirmed the accessibility of hSERT/F556 to different methanethiosulfonate (MTS) reagents, suggesting its presence in a hydrophilic environment of the protein. In the presence of MTSET, current induced by 5-HT and MPP(+) was inhibited at the F556C mutant. In agreement with our homology model of SERT, based on the leucine transporter (LeuT(Aa)) from Aquifex aeolicus structure, these results are consistent with the hypothesis that a portion of TMH XI lines the entrance into the substrate permeation pathway.
Collapse
Affiliation(s)
- Melissa I Torres-Altoro
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University School of Pharmacy and Pharmaceutical Sciences, West Lafayette, Indiana 47907-2091, USA
| | | | | | | | | |
Collapse
|
20
|
Murphy DL, Lesch KP. Targeting the murine serotonin transporter: insights into human neurobiology. Nat Rev Neurosci 2008; 9:85-96. [DOI: 10.1038/nrn2284] [Citation(s) in RCA: 344] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
21
|
Ravna AW, Sager G, Dahl SG, Sylte I. Membrane Transporters: Structure, Function and Targets for Drug Design. TOPICS IN MEDICINAL CHEMISTRY 2008. [DOI: 10.1007/7355_2008_023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
|
22
|
Abstract
Translocation through the extracellular vestibule and binding of leucine in the leucine transporter (LeuT) have been studied with molecular dynamics simulations. More than 0.1 mus of all-atom molecular dynamics simulations have been performed on different combinations of LeuT, bound substrate, and bound structural Na(+) ions to describe molecular events involved in substrate binding and in the formation of the occluded state and to investigate the dynamics of this state. Three structural features are found to be directly involved in the initial steps of leucine transport: a Na(+) ion directly coordinated to leucine (Na-1), two aromatic residues closing the binding site toward the extracellular vestibule (Tyr-108 and Phe-253), and a salt bridge in the extracellular vestibule (Arg-30 and Asp-404). These features account for observed differences between simulations of LeuT with and without bound substrate and for a possible pathway for leucine binding and thereby formation of the occluded LeuT binding site.
Collapse
|
23
|
Ravna AW, Sylte I, Sager G. Molecular model of the outward facing state of the human P-glycoprotein (ABCB1), and comparison to a model of the human MRP5 (ABCC5). Theor Biol Med Model 2007; 4:33. [PMID: 17803828 PMCID: PMC2211457 DOI: 10.1186/1742-4682-4-33] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 09/06/2007] [Indexed: 01/24/2023] Open
Abstract
Background Multidrug resistance is a particular limitation to cancer chemotherapy, antibiotic treatment and HIV medication. The ABC (ATP binding cassette) transporters human P-glycoprotein (ABCB1) and the human MRP5 (ABCC5) are involved in multidrug resistance. Results In order to elucidate structural and molecular concepts of multidrug resistance, we have constructed a molecular model of the ATP-bound outward facing conformation of the human multidrug resistance protein ABCB1 using the Sav1866 crystal structure as a template, and compared the ABCB1 model with a previous ABCC5 model. The electrostatic potential surface (EPS) of the ABCB1 substrate translocation chamber, which transports cationic amphiphilic and lipophilic substrates, was neutral with negative and weakly positive areas. In contrast, EPS of the ABCC5 substrate translocation chamber, which transports organic anions, was generally positive. Positive-negative ratios of amino acids in the TMDs of ABCB1 and ABCC5 were also analyzed, and the positive-negative ratio of charged amino acids was higher in the ABCC5 TMDs than in the ABCB1 TMDs. In the ABCB1 model residues Leu65 (transmembrane helix 1 (TMH1)), Ile306 (TMH5), Ile340 (TMH6) and Phe343 (TMH6) may form a binding site, and this is in accordance with previous site directed mutagenesis studies. Conclusion The Sav1866 X-ray structure may serve as a suitable template for the ABCB1 model, as it did with ABCC5. The EPS in the substrate translocation chambers and the positive-negative ratio of charged amino acids were in accordance with the transport of cationic amphiphilic and lipophilic substrates by ABCB1, and the transport of organic anions by ABCC5.
Collapse
Affiliation(s)
- Aina W Ravna
- Department of Pharmacology, Institute of Medical Biology, University of Tromsø, N-9037 Tromsø, Norway
| | - Ingebrigt Sylte
- Department of Pharmacology, Institute of Medical Biology, University of Tromsø, N-9037 Tromsø, Norway
| | - Georg Sager
- Department of Pharmacology, Institute of Medical Biology, University of Tromsø, N-9037 Tromsø, Norway
| |
Collapse
|
24
|
Jones PM, Turner KM, Djordjevic JT, Sorrell TC, Wright LC, George AM. Role of Conserved Active Site Residues in Catalysis by Phospholipase B1 from Cryptococcus neoformans. Biochemistry 2007; 46:10024-32. [PMID: 17685590 DOI: 10.1021/bi7009508] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phospholipase B1 (PLB1), secreted by the pathogenic yeast Cryptococcus neoformans, has an established role in virulence. Although the mechanism of its phospholipase B, lysophospholipase, and lysophospholipase transacylase activities is unknown, it possesses lipase, subtilisin protease aspartate, and phospholipase motifs containing putative catalytic residues S146, D392, and R108, respectively, conserved in fungal PLBs and essential for human cytosolic phospholipase A2 (cPLA2) catalysis. To determine the role of these residues in PLB1 catalysis, each was substituted with alanine, and the mutant cDNAs were expressed in Saccharomyces cerevisiae. The mutant PLB1s were deficient in all three enzymatic activities. As the active site structure of PLB1 is unknown, a homology model was developed, based on the X-ray structure of the cPLA2 catalytic domain. This shows that the two proteins share a closely related fold, with the three catalytic residues located in identical positions as part of a single active site, with S146 and D392 forming a catalytic dyad. The model suggests that PLB1 lacks the "lid" region which occludes the cPLA2 active site and provides a mechanism of interfacial activation. In silico substrate docking studies with cPLA2 reveal the binding mode of the lipid headgroup, confirming the catalytic dyad mechanism for the cleavage of the sn-2 ester bond within one of two separate binding tracts for the lipid acyl chains. Residues specific for binding arachidonic and palmitic acids, preferred substrates for cPLA2 and PLB1, respectively, are identified. These results provide an explanation for differences in substrate specificity between lipases sharing the cPLA2 catalytic domain fold and for the differential effect of inhibitors on PLB1 enzymatic activities.
Collapse
Affiliation(s)
- Peter M Jones
- Department of Medical and Molecular Biosciences, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia
| | | | | | | | | | | |
Collapse
|
25
|
Jørgensen AM, Tagmose L, Jørgensen AMM, Topiol S, Sabio M, Gundertofte K, Bøgesø KP, Peters GH. Homology Modeling of the Serotonin Transporter: Insights into the Primary Escitalopram-binding Site. ChemMedChem 2007; 2:815-26. [PMID: 17405130 DOI: 10.1002/cmdc.200600242] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The serotonin transporter (SERT) is one of the neurotransmitter transporters that plays a critical role in the regulation of endogenous amine concentrations and therefore is an important target for therapeutic agents affecting the central nervous system. The recently published, high resolution X-ray structure of the closely related amino acid transporter, Aquifex aeolicus leucine transporter (LeuT), provides an opportunity to develop a three-dimensional model of the structure of SERT. We present herein a homology model of SERT using LeuT as the template and containing escitalopram as a bound ligand. Our model explains selectivities known from mutational studies and varying ligand data, which are discussed and illustrated in the paper.
Collapse
Affiliation(s)
- Anne Marie Jørgensen
- MEMPHYS-Center for Biomembrane Physics, Department of Chemistry, Technical University of Denmark, Building 206, 2800 Kgs. Lyngby, Denmark
| | | | | | | | | | | | | | | |
Collapse
|