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Updated: Feb 3, 2026

Human Skeletal Muscle Biopsy Procedures Using the Modified Bergström Technique
Published on: September 10, 2014
Closed- and open-state models of human skeletal muscle sodium channel
João R C Fernandes1, Lucas Bleicher1, Paulo S L Beirão1
1Department of Biochemistry and Immunology - ICB, Universidade Federal de Minas Gerais - UFMG, Av. Antonio Carlos, 6627, 31270-901, Belo Horizonte, MG, Brazil.
Abstract:
Voltage-gated sodium channels play important roles in human physiology. However, their complexity hinders the understanding of their physiology and pathology at atomic level. We took advantage of the structural reports of similar channels obtained by cryo-EM (EeNav1.4, and NavPaS), and constructed models of human Nav1.4 channels at closed and open states. The open-state model is very similar to the recently published cryo-EM structure of hNav1.4. The comparison of both models shows shifts of the voltage sensors (VS) of DIII and DIV. The activated position of VS-DII in the closed model was demonstrated by Ts1 docking, thereby confirming the requirement that VS-DI, VS-DII and VS-DIII must be activated for the channel to open. The interactions observed with VS-DIII suggest a stepwise, yet fast, transition from resting to activated state. These models provide structural insights on the closed-open transition of the channel.
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