Glutamate-containing dipeptides enhance specific binding at glutamate receptors and inhibit specific binding at kainate receptors in rat brain.
The dipeptide, L-phenylalanyl-L-glutamate (PG), augments the specific binding of the excitatory amino acid receptor antagonist, [3H]2-amino-7-phosphonoheptanoic acid (APH), to rat forebrain membranes by 5-fold at 100 microM with an EC50 of 4.9 microM. The increase in the specific binding of [3H]AHP induced by PG results exclusively from an increase in Bmax. In contrast, PG inhibits the specific binding of [3H]kainic acid to forebrain membranes with a Ki of 6.8 microM. Of several related peptides examined, active ones affected the two receptor sites in a reciprocal fashion. The results suggest an allosteric interaction between [3H]APH and kainate receptors modulated by glutamate-containing peptides.
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives*; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004151:Dipeptides / Q000494:pharmacology*; D005971:Glutamates / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017470:Receptors, Glutamate; D018092:Kainic Acid Receptors; D014018:Tissue Distribution
D015763:2-Amino-5-phosphonovalerate; D000596:Amino Acids; D004151:Dipeptides; D005971:Glutamates; D011956:Receptors, Cell Surface; D017470:Receptors, Glutamate; D018092:Kainic Acid Receptors; C041371:phenylalanylglutamate; C031231:2-amino-7-phosphonoheptanoic acid