Freezing eliminates a specific population of L-glutamate receptors in synaptic membranes.
The binding of L-[3H]glutamate (L-Glu) to freeze-thawed synaptic membranes (SPMs) exhibited saturation kinetics, with Kd 507 nM and Bmax 6.99 pmol/mg protein. The effects of ions, the susceptibility to Triton X-100 and the pharmacological properties of the binding indicated that those sites detected in freeze-thawed SPMs were only of the Cl-/Ca2+-independent type. The Cl-/Ca2+-dependent (2-amino-4-phosphonobutyrate-sensitive) L-Glu binding sites which are additionally present in fresh SPMs are abolished by freezing.
D000613:Aminobutyrates / Q000494:pharmacology; D000818:Animals; D005615:Freezing; D007477:Ions; D007700:Kinetics; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D011956:Receptors, Cell Surface / Q000502:physiology*; D017470:Receptors, Glutamate; D013570:Synaptic Membranes / Q000378:metabolism*
D000613:Aminobutyrates; D007477:Ions; D011956:Receptors, Cell Surface; D017470:Receptors, Glutamate; D011092:Polyethylene Glycols; D017830:Octoxynol; C012729:2-amino-4-phosphonobutyric acid