PT  - JOURNAL ARTICLE
AU  - A I Sacaan
AU  - K M Johnson
TI  - Spermine enhances binding to the glycine site associated with the N-methyl-D-aspartate receptor complex.
DP  - 1989 Dec 01
TA  - Molecular Pharmacology
PG  - 836--839
VI  - 36
IP  - 6
4099  - http://molpharm.aspetjournals.org/content/36/6/836.short
4100  - http://molpharm.aspetjournals.org/content/36/6/836.full
SO  - Mol Pharmacol1989 Dec 01; 36
AB  - Spermine enhanced strychnine-insensitive [3H]glycine binding 3-fold with an EC50 of 27 +/- 3.1 microM. Spermidine and putrescine were without effect, whereas the ethylenediamine analog of spermine had an intermediate effect. Eadie-Hofstee analysis revealed that spermine increased the affinity of glycine for its receptor without a significant change in receptor density. This effect persisted in the presence of glycine or N-methyl-D-aspartate receptor antagonists. Furthermore, spermine produced a leftward shift in the IC50 of glycine agonists in displacing [3H]glycine binding, without altering the IC50 for glycine antagonists. These data indicate that spermine interacts with the glycine receptor through a novel binding site and, further, that spermine can be used to discriminate glycine agonist and antagonist binding.