Gostatin blocks physiological actions and binding of acidic amino acids in rat brain

Gostatin, an inhibitor of aspartate aminotransferases isolated from Streptomyces sumanensis NK-23, was tested as an antagonist of acidic amino acid-mediated responses in the in vitro hippocampal slice and of acidic amino acid binding. Gostatin blocked responses to N-methylaspartate more potently than responses to kainate, a-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) or L-glutamate. Gostatin also displaced N-methyl-D-aspartate-sensitive [ 3H]-L-glutamate binding (K i = 22.0 μM) more potently than [ 3H]-kainate binding. Gostatin appears to be a relatively nonselective acidic amino acid antagonist in the mammalian central nervous system.