Volume 272, Number 39,
Issue of September 26, 1997
pp. 24247-24251
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.
Carbamoylation of Brain Glutamate Receptors by a Disulfiram
Metabolite
(Received for publication, May 22, 1997)
S. Ningaraj
Nagendra
,
Morris D.
Faiman
,
Kathleen
Davis
¶
,
Jang-Yen
Wu
¶
,
Xiangyue
Newby
and
John
V.
Schloss
From the
Department of Pharmacology and Toxicology,
the ¶ Department of Physiology and Cell Biology, and the
Department of Medicinal Chemistry, University of Kansas,
Lawrence, Kansas 66045
S-Methyl-N,N-diethylthiolcarbamate
sulfoxide (DETC-MeSO), a metabolite of the drug disulfiram, is a
selective carbamoylating agent for sulfhydryl groups. Treatment of
glutamate receptors isolated from mouse brain with DETC-MeSO blocks
glutamate binding. In vivo, carbamoylated glutathione,
administered directly to mice or formed by reaction of DETC-MeSO with
glutathione in the blood, also blocks brain glutamate receptors.
Carbamoyl groups appear to be delivered to brain glutamate receptors or
to liver aldehyde dehydrogenase in vivo by a novel
glutathione-mediated mechanism. Seizures caused by the glutamate
analogs N-methyl-D-aspartate and methionine
sulfoximine, or by hyperbaric oxygen, are prevented by DETC-MeSO,
indicating that carbamoylation of glutamate receptors gives an
antagonist effect. These observations offer an explanation for some of
the previously reported neurological effects of disulfiram, such as its
ability to prevent O2-induced seizures. Furthermore, some
of the physiology of the disulfiram-ethanol reaction, that could not be
accounted for based on the known inhibition of aldehyde dehydrogenase
alone, may be explained by disulfiram's effect on glutamate
receptors.