Linked Life Data

3022871

Source:http://linkedlifedata.com/resource/pubmed/id/3022871

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1987-1-6
pubmed:abstractText
L-, D- and DL-quisqualic acid have been synthesized and their activities at the glutamatergic locust nerve-muscle junction have been compared with those of natural quisqualic acid and with glutamic acid. Two well-characterised locust nerve-muscle preparations were used in these studies, the retractor unguis nerve-muscle system and the extensor tibiae nerve-muscle system. The amino acids were tested on the whole nerve-muscle system in the former, when reduction in neurally evoked twitch contraction amplitude was the measured parameter, and by ionophoretic application to single excitatory junctional sites in the latter, when amplitude of junctional depolarization was the measured parameter. Synthetic L-quisqualic acid exhibited identical potency to its natural counterpart. However, D-quisqualic acid and DL-quisqualic acid were more active than expected from the known stereospecificity of this glutamatergic system towards D- and L-glutamic acid. The hydantoin analogue of quisqualic acid was inactive. X-ray crystallographic analysis of L-quisqualic acid and the hydantoin analogue showed that the ring junction in the former is pyramidal whereas in the latter it is planar. This may account for the high potency of L-quisqualic acid on a receptor system which identifies a partially folded conformation of L-glutamic acid. A pyramidal configuration of D-quisqualic acid would allow either rapid interconversion between active and inactive configurations at its ring junction or adoption of a trigonal configuration in solution. Either interpretation could explain the unexpected potency of D-quisqualic acid.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
385
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
205-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
The action of natural and synthetic isomers of quisqualic acid at a well-defined glutamatergic synapse.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't