The effect on ion channel of different protonation states of E90 in channelrhodopsin-2: a molecular dynamics simulation.

ABSTRACT: Channelrhodopsin-2 (ChR2) is a cationic channel protein that has been extensively studied in optogenetics. The ion channel is opened via a series of proton transfers and H-bond changes during the photocycle but the detailed mechanism is still unknown. Molecular dynamics (MD) simulations with enhanced sampling were performed on the dark-adapted state (i.e., D470) and two photocycle intermediates (P₁ ⁵⁰⁰ and P₂ ³⁹⁰) to study the proton transfer path of the Schiff base and the subsequent conformational changes. The results suggest there are two possible proton transfer pathways from the Schiff base to proton acceptors (i.e., E123 or D253), depending on the protonation of E90. If E90 is protonated in the P₁ ⁵⁰⁰

SUBMITTER: Cheng J 

PROVIDER: S-EPMC8697799 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature