Gamma-L-glutamyl-L-glutamate is an endogenous dipeptide in the rat olfactory bulb which activates N-methyl-D-aspartate receptors.
The concentration of gamma-L-glutamyl-L-glutamate (gamma-glu-glu), a potent displacer of excitatory amino acid receptor binding, and other structurally related dipeptides were determined in extracts of the rat olfactory bulb by a novel liquid chromatographic method. Whole-cell patch clamp recordings of currents from freshly isolated neurons showed that gamma-glu-glu produced inward currents at negative holding potentials, provided microM concentrations of glycine were added and no Mg(2+)-ions were present, indicating activation of N-methyl-D-aspartate receptors. Consistently, geometry optimization of gamma-glu-glu using molecular mechanics calculations, suggested a bent conformer with structural features supporting this view.
Li
X
X
Institute of Neurobiology, University of Göteborg, Sweden.
Orwar
O
O
Persson
J
J
Sandberg
M
M
Jacobson
I
I
D000818:Animals; D002469:Cell Separation; D002853:Chromatography, Liquid / Q000379:methods; D004151:Dipeptides / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D004594:Electrophysiology; D005971:Glutamates / Q000494:pharmacology / Q000502:physiology*; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D009830:Olfactory Bulb / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D004151:Dipeptides; D005971:Glutamates; D016194:Receptors, N-Methyl-D-Aspartate; C082810:gamma-glutamylglutamate