Characterisation of Na+-independent L-[3H]glutamate binding sites in human temporal cortex.
The binding of L-[3H]glutamate to membranes from human temporal cortex was studied in the absence of Na+, Ca2+, and Cl- ions. Pharmacological characterisation revealed that approximately 35% of specific binding at 50 nM L-[3H]glutamate was sensitive to a combination of kainate and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid. The remaining approximately 65% of specific binding was to a single population of sites with a KD of 844 nM and a Bmax of 0.92 pmol/mg protein. The pharmacological characteristics were consistent with an interaction at the N-methyl-D-aspartate subclass of excitatory amino acid receptor. The inclusion of Cl- ions revealed additional glutamate binding; this was sensitive to quisqualate and DL-2-amino-4-phosphonobutyrate, but not to kainate, DL-2-amino-7-phosphonoheptanoate, or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid.
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives*; D000368:Aged; D000596:Amino Acids / Q000494:pharmacology; D000613:Aminobutyrates / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002712:Chlorides / Q000494:pharmacology; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D006801:Humans; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010069:Oxadiazoles / Q000494:pharmacology; D016318:Quisqualic Acid; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology; D013702:Temporal Lobe / Q000187:drug effects / Q000378:metabolism*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D000596:Amino Acids; D000613:Aminobutyrates; D002712:Chlorides; D005971:Glutamates; D010069:Oxadiazoles; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D007051:Ibotenic Acid; D018698:Glutamic Acid; D015763:2-Amino-5-phosphonovalerate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D016318:Quisqualic Acid; D012964:Sodium; C012729:2-amino-4-phosphonobutyric acid; C031231:2-amino-7-phosphonoheptanoic acid; D007608:Kainic Acid