Displaceable binding of [3H]l-glutamic acid to non-receptor materials.
[3H]L-glutamic acid binding to microfuge tubes and glass was investigated in four buffers. Background binding to these materials was negligible, but was increased by centrifugation or suction in Tris-HCl and Tris-citrate buffer. This binding was much less or eliminated when HEPES-KOH, or Tris-acetate buffer was used instead. [3H]L-glutamate binding to microfuge tubes was inhibited by L- but not D-isomers of glutamate and aspartate. DL-2-amino-7-phosphonoheptanoic acid also did not inhibit the binding. Other compounds which showed low to moderate inhibition were: N-methyl-D-aspartate, quisqualate, L-glutamic acid diethyl ester, N-methyl-L-aspartate, kainate, and 2-amino-4-phosphonobutyrate. Binding was inhibited by denatured rat brain membranes. A protein-dependent [3H]glutamate binding was obtained with a repeatedly frozen-thawed membrane preparation when binding was done in Tris-acetate buffer. It is recommended that Tris-acetate or HEPES-KOH buffer should be used in the glutamate binding assay. If Tris-HCl or Tris-citrate buffer is used, appropriate control experiment should be done to correct for binding to microfuge tubes or glass fiber filters.
Ito
M
M
Periyasamy
S
S
Chiu
T H
TH
D000818:Animals; D001921:Brain / Q000378:metabolism; D002498:Centrifugation / Q000295:instrumentation; D005189:False Positive Reactions; D005374:Filtration / Q000295:instrumentation; D005615:Freezing; D005898:Glass; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D007425:Intracellular Membranes / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D051381:Rats; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000378:metabolism*
D005971:Glutamates; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D018698:Glutamic Acid