The nicotinic acetylcholine receptor channel (AChR) is an allosteric membrane protein that mediates neuromuscular transmission in vertebrates. Experiments are proposed regarding the kinetic properties of wild type and mutant mouse recombinant AChR, probed using single-channel electrophysiology. Three areas that are of fundamental importance with regard to understanding synaptic receptor channels are addressed: agonist binding, channel gating, and desensitization. One goal of this proposal is to understand the mechanisms of molecular recognition at the transmitter binding sites. Experiments are proposed to study the nature of the agonist-protein interactions with both high and low affinity conformations of the AChR. The second objective is to use linear free energy relationships to obtain a snapshot of the gating transition state. These experiments will report the order of events during the closed-open allosteric transition.
The third aim i s to understand the molecular basis of desensitization. Experiments are proposed to make high-resolution measurements of desensitization recovery rate constants in both wild type and mutant AChR. The results of the experiments will provide a deep, mechanistic understanding of AChR both at normal synapses, and at synapses that have been compromised by neuromuscular disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37NS023513-18
Application #
7039222
Study Section
Special Emphasis Panel (ZRG1-MDCN-3 (01))
Program Officer
Silberberg, Shai D
Project Start
1987-07-01
Project End
2007-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
18
Fiscal Year
2006
Total Cost
$473,540
Indirect Cost
Name
State University of New York at Buffalo
Department
Physiology
Type
Schools of Medicine
DUNS #
038633251
City
Buffalo
State
NY
Country
United States
Zip Code
14260
Gupta, Shaweta; Chakraborty, Srirupa; Vij, Ridhima et al. (2017) A mechanism for acetylcholine receptor gating based on structure, coupling, phi, and flip. J Gen Physiol 149:85-103
Purohit, Prasad; Chakraborty, Srirupa; Auerbach, Anthony (2015) Function of the M1 ?-helix in endplate receptor activation and desensitization. J Physiol 593:2851-66
Auerbach, Anthony (2015) Agonist activation of a nicotinic acetylcholine receptor. Neuropharmacology 96:150-6
Nayak, Tapan K; Bruhova, Iva; Chakraborty, Srirupa et al. (2014) Functional differences between neurotransmitter binding sites of muscle acetylcholine receptors. Proc Natl Acad Sci U S A 111:17660-5
Purohit, Prasad; Bruhova, Iva; Gupta, Shaweta et al. (2014) Catch-and-hold activation of muscle acetylcholine receptors having transmitter binding site mutations. Biophys J 107:88-99
Purohit, Prasad; Gupta, Shaweta; Jadey, Snehal et al. (2013) Functional anatomy of an allosteric protein. Nat Commun 4:2984
Purohit, Prasad; Auerbach, Anthony (2013) Loop C and the mechanism of acetylcholine receptor-channel gating. J Gen Physiol 141:467-78
Jadey, Snehal; Purohit, Prasad; Auerbach, Anthony (2013) Action of nicotine and analogs on acetylcholine receptors having mutations of transmitter-binding site residue ýýG153. J Gen Physiol 141:95-104
Nayak, Tapan K; Auerbach, Anthony (2013) Asymmetric transmitter binding sites of fetal muscle acetylcholine receptors shape their synaptic response. Proc Natl Acad Sci U S A 110:13654-9
Gupta, Shaweta; Purohit, Prasad; Auerbach, Anthony (2013) Function of interfacial prolines at the transmitter-binding sites of the neuromuscular acetylcholine receptor. J Biol Chem 288:12667-79

Showing the most recent 10 out of 54 publications