Single Channel Kinetics of a Glutamate Receptor

• Published in: Biophysical journal Vol. 50; no. 2; pp. 367 - 374
• Main Authors: Kerry, Cathryn J., Kits, Karel S., Ramsey, Robert L., Sansom, Mark S.P., Usherwood, Peter N.R.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.08.1986; Biophysical Society
• Subjects: ACIDE GLUTAMIQUE; ACIDO GLUTAMICO; Biochemistry. Physiology. Immunology; Biological and medical sciences; CELL STRUCTURE; ESTRUCTURA CELULAR; Fundamental and applied biological sciences. Psychology; GLUTAMIC ACID; Insecta; Invertebrates; NEUROTRANSMITTERS; Physiology. Development; SCHISTOCERCA; SCHISTOCERCA GREGARIA; STRUCTURE CELLULAIRE; Membrane receptor; Arthropoda; Insecta; Orthoptera; Electrophysiology; Muscle; Invertebrata; Glutamate
• ISSN: 0006-3495; 1542-0086
• DOI: 10.1016/S0006-3495(86)83470-1

The glutamate receptor-channel of locust muscle membrane was studied using the patch-clamp technique. Muscles were pretreated with concanavalin A to block receptor-channel desensitization, thus facilitating analysis of receptor-channel gating kinetics. Single channel kinetics were analyzed to aid in identification of the molecular basis of channel gating. Channel dwell-time distributions and dwell-time autocorrelation functions were calculated from single channel data recorded in the presence of 10 -4 M glutamate. Analysis of the dwell time distributions in terms of mixtures of exponential functions revealed there to be at least three open states of the receptor-channel and at least four closed states. Autocorrelation function analysis showed there to be at least three pathways linking the open states with the closed. This results in a minimal scheme for gating of the glutamate receptor-channel, which is suggestive of allosteric models of receptor-channel gating.