Capturing state-dependent dynamic events of GABAA-receptors: a microscopic look into the structural and functional insights |
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Authors: | Pavan V Payghan Indrani Bera Dhananjay Bhattacharyya |
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Institution: | 1. Structural Biology and Bioinformatics Division, CSIR – Indian Institute of Chemical Biology, Kolkata 700032, India;2. Computational Science Division, Saha Institute of Nuclear Physics, Kolkata 700 064, India |
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Abstract: | The γ-amino butyric acid type A receptors (GABAA-Rs) are the key players in the mammalian brain that meditate fast inhibitory neurotransmission events. The structural integrity of these ligand-gated ion channel controls chloride ion permeability, which in turn monitors important pharmacological functions. Despite ample studies on GABAA-Rs, there was a need for a study on full-length receptor structures, devoted to track structure–function correlations based on their dynamic behavior consideration. We have employed molecular dynamics simulations accompanied by other biophysical methods to shed light on sequential and unaddressed questions like How GABAA-R structure facilitates the entry of GABA molecules at its two orthosteric binding sites? After entry, what structural features and changes monitor site-wise GABA binding differences? In the same context, what are the roles and responsibilities of loops such as C and F? On physiologically relevant time scales, how open to close state transition occurs? How salt bridges such as E155-R207 and E153-R207 maintain state-dependent C-loop structures? In an attempt, our simulation study unravels the complete course of GABA binding-unbinding pathway. This provides us with the relevant understanding of state-dependent dynamic events of GABAA-Rs. |
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Keywords: | GABAA-Receptor GABA pentameric ligand-gated ion channel molecular dynamics simulations Inhibitory PostSynaptic Currents |
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