Work

Atomistic Details of Charge/Space Competition in the Ca2+ Selectivity of Ryanodine Receptors

Year: 2021

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Ryanodine receptors (RyRs) are ion channels responsible for the fast release of Ca 2+ from the sarco/endoplasmic reticulum to the cytosol and show a selectivity of Ca 2+ over monovalent cations. By utilizing a recently developed multisite Ca 2+ model in molecular dynamic simulations, we show that multiple cations accumulate in the upper selectivity filter of RyRs, and the small size and high valence of Ca 2+ make it preferable to K + in competition for space in this confined region of negative electrostatic potential. The presence of Ca 2+ in the upper selectivity filter significantly increases the energy barrier of K + permeation, while the presence of K + has little impact on the Ca 2+ permeation. Our results provide the atomistic details of the charge/space competition mechanism for the ion selectivity of RyRs, which ensures the robustness of their Ca 2+ release function. The mechanism could be utilized in protein- and nanoengineering for valence selectivity of ion species.

Source: The Journal of Physical Chemistry Letters

DOI: 10.1021/acs.jpclett.1c00681

Authors: Chunhong Liu, Aihua Zhang, Nieng Yan, Chen Song

Institutions: Peking University, Princeton University, Center for Life Sciences

Language: English

Topic: Ion channel regulation and function

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $5,000

Funders: National Natural Science Foundation of China, Ministry of Science and Technology of the People's Republic of China