Chaotropic ions affect the conformation of quisqualate receptors in rat cortical membranes.
Binding of [3H](R,S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid ([3H]AMPA) to quisqualate receptors in the presence of SCN- ions produced curvilinear Scatchard plots. Kinetic investigations of [3H]AMPA binding showed that the curvilinearity cannot be explained by assuming binding to two separate binding sites or by considering it due to cooperative interaction. A more likely explanation is that the quisqualate receptors exist in two states, one with high and one with low affinity for [3H]AMPA. Chaotropic ions change the relaxation constant between the two states.
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D003485:Cyanates / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology*; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D007700:Kinetics; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D011487:Protein Conformation / Q000187:drug effects; D051381:Rats; D018091:Receptors, AMPA; D011955:Receptors, Drug / Q000187:drug effects*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D003485:Cyanates; D003486:Cyanides; D018091:Receptors, AMPA; D011955:Receptors, Drug; D007051:Ibotenic Acid; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid