Conformationally Defined Neurotransmitter Analogues. Selective Inhibition of Glutamate Uptake by One Pyrrolidine-2,4-dicarboxylate Diastereomer

Article abstract of DOI:10.1021/jm00106a037

In order to determine the conformational requirements for binding of L-glutamate to the proteins involved in the process of neurotransmission, rigid analogues containing an embedded glutamate moiety have been prepared.These "conformer mimics", the pyrrolidine-2,4-dicarboxylates 4, 7, 11, and 14, were synthesized from commercially available trans-4-hydroxy-L-proline and cis-4-hydroxy-D-proline, and then were tested for their ability to inhibit the high-affinity transport of <3H>-L-glutamate into synaptosomes and to block the binding of radioligands to the NMDA (N-methyl-D-aspartate), KA (kainate), and QA (quisqualate) glutamate neurotransmitter receptor sites.While none of the four analogues binds effectively to the excitatory receptors, the L-trans-isomer 7 is a potent and selective competitive inhibitor of L-glutamate transport.These results delineate a specific structural/conformational preference for binding to the uptake system that is distinct from that required for binding to the NMDA, KA, and QA receptors.