E224G Regulation of the PIP2-Induced Gating Kinetics of Kir2.1 Channels

As a member of the inwardly rectifying channel (Kir) family, Kir2.1 allows to influx the cell more easily than to efflux, a biophysical phenomenon named inward rectification. The function of Kir2.1 is to set the resting membrane potential and modulate membrane excitability. It has been reported that residue E224 plays a key role in regulating inward rectification. The mutant Kir2.1 (E224G) displays weaker inward rectification than the WT channel. Gating of Kir2.1 depends on the membrane lipid, PIP2, such that the channel gates are closed in the absence of PIP2. Here we perform electrophysiological and computational approaches, and demonstrate that E224 also plays an important role in the PIP2-dependent activation of Kir2.1 in addition to its influence on inward rectification. The E224G mutant takes 4.5 times longer to be activated by PIP2. To probe the mechanism by which E224G slows the channel opening kinetics, we perform targeted molecular dynamics simulations and find that the mutant weakens the interactions between CD-loop and C-linker (H221-R189) and the adjacent G-loops (R312-E303) which are thought to stabilize the open state of the channel in our previous work. These data provide new insights into the regulation of Kir2.1 channel activity and suggest that a common mechanism may be involved in the distinct biophysical processes, such as inward rectification and PIP2-induced gating.

Recent advances in elaborate interface regulation of BiVO_(4)photoanode for photoelectrochemical water splitting

Bismuth vanadate(BiVO_(4))is an excellent photoanode material for photoelectrochemical(PEC)water splitting system,possessing high theoretical photoelectrocatalytic conversion efficiency.However,the actual PEC activity and stability of BiVO_(4)are faced with great challenges due to factors such as severe charge recombination and slow water oxidation kinetics at the interface.Therefore,various interface regulation strategies have been adopted to optimize the BiVO_(4)photoanode.This review provides an in-depth analysis for the mechanism of interface regulation strategies from the perspective of factors affecting the PEC performance of BiVO_(4)photoanodes.These interface regulation strategies improve the PEC performance of BiVO_(4)photoanode by promoting charge separation and transfer,accelerating interfacial reaction kinetics,and enhancing stability.The research on the interface regulation strategies of BiVO_(4)photoanode is of great significance for promoting the development of PEC water splitting technology.At the same time,it also has inspiration for providing new ideas and methods for designing and preparing efficient and stable catalytic materials.

Improving sulfur transformation of lean electrolyte lithium-sulfur battery using nickel nanoparticles encapsulated in N-doped carbon nanotubes

Efficient redox reactions of lean electrolyte lithium-sulfur(Li-S)batteries highly rely on rational catalyst design.Herein,we report an electrocatalyst based on N-doped carbon nanotubes(CNT)-encapsulated Ni nanoparticles(Ni@NCNT)as kinetics regulators for Li-S batteries to propel the polysulfide-involving multiphase transformation.Moreover,such a CNT-encapsulation strategy greatly prevents the aggregation of Ni nanoparticles and enables the extraordinary structural stability of the hybrid electrocatalyst,which guarantees its persistent catalytic activity on sulfur redox reactions.When used as a modified layer on a commercial separator,the Ni@NCNT interlayer contributes to stabilizing S cathode and Li anode by significantly retarding the shuttle effect.The corresponding batteries with a 3.5 mg cm^(−2)sulfur loading achieve the promising cycle stability with~85%capacity retention at the electrolyte/sulfur ratios of 5 and 3μL mg^(−1).Even at a high loading of 12.2 mg cm^(−2),the battery affords an areal capacity of 7.5 mA h cm^(−2).