Binding of ArgTX-636 in the NMDA receptor ion channel
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Binding of ArgTX-636 in the NMDA receptor ion channel. / Poulsen, Mette H; Andersen, Jacob; Christensen, Rune; Hansen, Kasper Bø; Traynelis, Stephen F; Strømgaard, Kristian; Kristensen, Anders Skov.
In: Journal of Molecular Biology, Vol. 427, No. 1, 16.01.2015, p. 176-89.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Binding of ArgTX-636 in the NMDA receptor ion channel
AU - Poulsen, Mette H
AU - Andersen, Jacob
AU - Christensen, Rune
AU - Hansen, Kasper Bø
AU - Traynelis, Stephen F
AU - Strømgaard, Kristian
AU - Kristensen, Anders Skov
N1 - Copyright © 2014 Elsevier Ltd. All rights reserved.
PY - 2015/1/16
Y1 - 2015/1/16
N2 - The N-methyl-d-aspartate receptors (NMDARs) constitute an important class of ligand-gated cation channels that are involved in the majority of excitatory neurotransmission in the human brain. Compounds that bind in the NMDAR ion channel and act as blockers are use- and voltage-dependent inhibitors of NMDAR activity and have therapeutic potential for treatment of a variety of brain diseases or as pharmacological tools for studies of the neurobiological role of NMDARs. We have performed a kinetic analysis of the blocking mechanism of the prototypical polyamine toxin NMDAR ion channel blocker argiotoxin-636 (ArgTX-636) at recombinant GluN1/2A receptors to provide detailed information on the mechanism of block. The predicted binding site of ArgTX-636 is in the pore region of the NMDAR ion channel formed by residues in the transmembrane M3 and the M2 pore-loop segments of the GluN1 and GluN2A subunits. To assess the predicted binding mode in further detail, we performed an alanine- and glycine-scanning mutational analysis of this pore-loop segment to systematically probe the role of pore-lining M2 residues in GluN1 and GluN2A in the channel block by ArgTX-636. Comparison of M2 positions in GluN1 and GluN2A where mutation influences ArgTX-636 potency suggests differential contribution of the M2-loops of GluN1 and GluN2A to binding of ArgTX-636. The results of the mutational analysis are highly relevant for the future structure-based development of argiotoxin-derived NMDAR channel blockers.
AB - The N-methyl-d-aspartate receptors (NMDARs) constitute an important class of ligand-gated cation channels that are involved in the majority of excitatory neurotransmission in the human brain. Compounds that bind in the NMDAR ion channel and act as blockers are use- and voltage-dependent inhibitors of NMDAR activity and have therapeutic potential for treatment of a variety of brain diseases or as pharmacological tools for studies of the neurobiological role of NMDARs. We have performed a kinetic analysis of the blocking mechanism of the prototypical polyamine toxin NMDAR ion channel blocker argiotoxin-636 (ArgTX-636) at recombinant GluN1/2A receptors to provide detailed information on the mechanism of block. The predicted binding site of ArgTX-636 is in the pore region of the NMDAR ion channel formed by residues in the transmembrane M3 and the M2 pore-loop segments of the GluN1 and GluN2A subunits. To assess the predicted binding mode in further detail, we performed an alanine- and glycine-scanning mutational analysis of this pore-loop segment to systematically probe the role of pore-lining M2 residues in GluN1 and GluN2A in the channel block by ArgTX-636. Comparison of M2 positions in GluN1 and GluN2A where mutation influences ArgTX-636 potency suggests differential contribution of the M2-loops of GluN1 and GluN2A to binding of ArgTX-636. The results of the mutational analysis are highly relevant for the future structure-based development of argiotoxin-derived NMDAR channel blockers.
KW - Animals
KW - Binding Sites
KW - Electrophysiology
KW - Glutamic Acid
KW - HEK293 Cells
KW - Humans
KW - Indoleacetic Acids
KW - Ion Channels
KW - Kinetics
KW - Models, Molecular
KW - Mutagenesis
KW - Mutation
KW - Patch-Clamp Techniques
KW - Polyamines
KW - Protein Conformation
KW - Protein Subunits
KW - Rats
KW - Receptors, N-Methyl-D-Aspartate
KW - Recombinant Fusion Proteins
KW - Spider Venoms
U2 - 10.1016/j.jmb.2014.05.017
DO - 10.1016/j.jmb.2014.05.017
M3 - Journal article
C2 - 24862283
VL - 427
SP - 176
EP - 189
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 1
ER -
ID: 138769639