UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Interactions of glycine and strychnine with their receptor recognition sites in mouse spinal cord

O'Connor, V; Phelan, PP; Fry, JP; (1996) Interactions of glycine and strychnine with their receptor recognition sites in mouse spinal cord. Neurochemistry International , 29 (4) pp. 423-434. 10.1016/0197-0186(95)00160-3.

[img] Text
Fry_O'Connor%2C Phelan %26 Fry 1996.pdf
Access restricted to UCL open access staff

Download (2MB)

Abstract

Interactions between the inhibitory neurotransmitter glycine and its receptor antagonist strychnine have been studied in mouse spinal cord membranes and both agents employed to protect against residue selective protein modifying reagents in order to identify contact residues for ligand binding. Glycine was found to behave as a full competitive inhibitor of [3H]-strychnine binding, provided that precautions were taken to prevent radioligand binding to the glass-fibre filters used to terminate the assays. Hill coefficients for the glycine inhibition of [3H]-strychnine binding were not significantly different from one, indicating a lack of cooperative interactions. For the protection experiments, N-bromosuccinimide, tetranitromethane, diethylpyrocarbonate and 2,3-butanedione were used under conditions selective for tryptophan, tyrosine, histidine and arginine residues, respectively. Of these reagents, N-bromosuccinimide, tetranitromethane and diethylpyrocarbonate caused a decrease in total [3H]-strychnine binding without affecting the ability of unlabelled strychnine to compete. In contrast, the same reagents disrupted the ability of glycine to inhibit [3H]-strychnine binding. The presence of either excess glycine (10(-2) M) or strychnine (10(-4) M) during the above treatments was found to prevent the decrease in total and strychnine-specific [3H]-strychnine binding. However, only in the case of diethylpyrocarbonate treatment were both agonist and antagonist able to protect against the loss of glycine-specific [3H]-strychnine binding. The reagent 2,3-butanedione caused an increase in total and strychnine-specific [3H]-strychnine binding (which we have shown elsewhere to be at a site unrelated to the inhibitory glycine receptor). When the above protein modifying reagents were applied under the same conditions to specific strychnine binding antibodies, all four caused significant decreases in subsequent [3H]-strychnine binding. Strychnine was found to afford significant protection of the antibodies against N-bromosuccinimide, tetranitromethane and 2,3-butanedione, but not against diethylpyrocarbonate. Our results suggest that glycine and strychnine compete at overlapping but conformationally distinct sites on the receptor. Tyrosine, tryptophan, histidine and arginine residues are implicated as strychnine contact residues with a shared role for histidine in the recognition of glycine.

Type: Article
Title: Interactions of glycine and strychnine with their receptor recognition sites in mouse spinal cord
Location: ENGLAND
DOI: 10.1016/0197-0186(95)00160-3
Publisher version: http://dx.doi.org/10.1016/0197-0186(95)00160-3
Language: English
Keywords: Animals, Antibodies, Glycine, Male, Mice, Mice, Inbred C57BL, Rabbits, Spinal Cord, Strychnine, Taurine, beta-Alanine, gamma-Aminobutyric Acid
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Neuro, Physiology and Pharmacology
URI: https://discovery.ucl.ac.uk/id/eprint/120535
Downloads since deposit
0Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item