Ion channel properties of a protein complex with characteristics of a glutamate/N-methyl-D-aspartate receptor.
The functional reconstitution of glutamate receptor proteins purified from mammalian brain has been difficult to accomplish. However, channels activated by L-glutamate (L-Glu) and N-methyl-D-aspartate (NMDA) were detected in planar lipid bilayer membranes (PLMs) following the reconstitution of a complex of proteins with binding sites for NMDA receptor (NMDAR) ligands. The presence of glycine was necessary for optimal activation. A linear current-voltage relationship was observed with the reversal potential being zero. Channels activated by L-Glu had conductances of 23, 47 and 65 pS, and were suppressed partially by competitive and fully by noncompetitive inhibitors of NMDARs. Magnesium had little effect on the reconstituted channels.
Aistrup
G L
GL
Department of Biochemistry, Center for Neurobiology and Immunology Research, University of Kansas, Lawrence 66045, USA.
Szentirmay
M
M
Kumar
K N
KN
Babcock
K K
KK
Schowen
R L
RL
Michaelis
E K
EK
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D005998:Glycine / Q000494:pharmacology; D007473:Ion Channels / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D018408:Patch-Clamp Techniques; D051381:Rats; D017470:Receptors, Glutamate / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013570:Synaptic Membranes / Q000737:chemistry*
D018691:Excitatory Amino Acid Antagonists; D007473:Ion Channels; D008051:Lipid Bilayers; D008081:Liposomes; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D001224:Aspartic Acid; D018698:Glutamic Acid; D015763:2-Amino-5-phosphonovalerate; D002118:Calcium; D005998:Glycine