Superionic Conduction in K3SbS4 Enabled by Cl-Modified Anion Lattice.

All-solid-state potassium batteries emerge as promising alternatives to lithium batteries, leveraging their high natural abundance and cost-effectiveness. Developing potassium solid electrolytes (SEs) with high room-temperature ionic conductivity is critical for realizing efficient potassium batteries. In this study, we present the synthesis of K2.98Sb0.91S3.53Cl0.47, showcasing a room-temperature ionic conductivity of 0.32 mS/cm and a low activation energy of 0.26 eV. This represents an increase of over two orders of magnitude compared to the parent compound K3SbS4, marking the highest reported ionic conductivity for non-oxide potassium SEs. Solid-state 39K magic-angle-spinning nuclear magnetic resonance on K2.98Sb0.91S3.53Cl0.47 reveals an increased population of mobile K+ ions with fast dynamics. Ab initio molecular dynamics (AIMD) simulations further confirm a delocalized K+ density and significantly enhanced K+ diffusion. This work demonstrates diversification of the anion sublattice as an effective approach to enhance ion transport and highlights K2.98Sb0.91S3.53Cl0.47 as a promising SE for all-solid-state potassium batteries.

Genome-wide identification and expression analysis of the HAK/KUP/KT gene family in Moso bamboo.

The K+ uptake permease/high-affinity K+/K+ transporter (KUP/HAK/KT) family is the most prominent group of potassium (K+) transporters, playing a key role in K+ uptake, transport, plant growth and development, and stress tolerance. However, the presence and functions of the KUP/HAK/KT family in Moso bamboo (Phyllostachys edulis (Carriere) J. Houzeau), the fastest-growing plant, have not been studied. In this study, we identified 41 KUP/HAK/KT genes (PeHAKs) distributed across 18 chromosomal scaffolds of the Moso bamboo genome. PeHAK is a typical membrane protein with a conserved structural domain and motifs. Phylogenetic tree analysis classified PeHAKs into four distinct clusters, while collinearity analysis revealed gene duplications resulting from purifying selection, including both tandem and segmental duplications. Enrichment analysis of promoter cis-acting elements suggested their plausible role in abiotic stress response and hormone induction. Transcriptomic data and STEM analyses indicated that PeHAKs were involved in tissue and organ development, rapid growth, and responded to different abiotic stress conditions. Subcellular localization analysis demonstrated that PeHAKs are predominantly expressed at the cell membrane. In-situ PCR experiments confirmed that PeHAK was mainly expressed in the lateral root primordia. Furthermore, the involvement of PeHAKs in potassium ion transport was confirmed by studying the potassium ion transport properties of a yeast mutant. Additionally, through homology modeling, we revealed the structural properties of HAK as a transmembrane protein associated with potassium ion transport. This research provides a solid basis for understanding the classification, characterization, and functional analysis of the PeHAK family in Moso bamboo.

Leptospiral c-di-AMP-binding protein regulates potassium ion transport / 中华微生物学和免疫学杂志

Objective:To investigate whether KtrA was a binding protein of c-di-AMP, the second messenger in Leptospira, and to explore the function and regulatory mechanism of the c-di-AMP-KtrA/B system. Methods:KtrA gene was amplified by PCR and cloned into pET42a plasmid to construct the pET42a ktrA prokaryotic expression vector. Then the vector was transferred into E. coli BL21DE3 to construct an engineering bacterium E. coli BL21DE3 pET42a-ktrA for the expression of recombinant KtrA (rKtrA). The expressed rKtrA was purified by affinity chromatography. BIAcore technology was used to detect the binding ability of rKtrA to c-di-AMP. Bacterial two-hybrid analysis was used to analyze the interaction between KtrA and KtrB in the leptospiral Ktr system with or without exogenetic c-di-AMP. The above genes were then complemented into the potassium transport-deficient E. coli mutants to analyze the function of the c-di-AMP-KtrA/B pathway. Results:An prokaryotic engineering bacterium for the expression of ktrA gene of Leptospira was constructed successfully. The purified rKtrA could specifically bind to c-di-AMP. There was interaction between KtrA and KtrB, but the interaction could be dissociated by c-di-AMP. The KtrA/B system was involved in potassium ion uptake and it was negatively regulated by c-di-AMP. Conclusions:Leptospiral KtrA was a c-di-AMP-binding protein and the c-di-AMP-KtrA/B system was involved in potassium ion transport.

Inhibition of Regulatory Volume Decrease Enhances the Cytocidal Effect of Hypotonic Shock in Hepatocellular Carcinoma.

Background : Hypotonic shock induces cytocidal effects through cell rupture, and cancer therapy based on this mechanism has been clinically administered to hepatocellular carcinoma patients. We herein investigated the effectiveness of hypotonic shock combined with the inhibition of regulatory volume decrease as cancer therapy for hepatocellular carcinoma. Methods : Morphological changes in human hepatocellular carcinoma cell lines were observed under a differential interference contrast microscope connected to a high-speed digital video camera. Cell volume changes under hypotonic shock with or without chloride, potassium, or water channel blockers were observed using a high-resolution flow cytometer. In order to investigate cytocidal effects, the number of surviving cells was compared after exposure to hypotonic solution with and without each channel blocker (re-incubation experiment). Results : Video recordings showed that cells exposed to distilled water rapidly swelled and then ruptured. Cell volume measurements revealed regulatory volume decrease under mild hypotonic shock, whereas severe hypotonic shock increased the number of broken fragments as a result of cell rupture. Moreover, regulatory volume decrease was inhibited in cells treated with each channel blocker. Re-incubation experiments showed the cytocidal effects of hypotonic shock in cells exposed to hypotonic solution, and additional treatments with each channel blocker enhanced these effects. Conclusion : The inhibition of regulatory volume decrease with chloride, potassium, or water channel blockers may enhance the cytocidal effects of hypotonic shock in hepatocellular carcinoma. Hypotonic shock combined with the inhibition of regulatory volume decrease was a more effective therapy than hypotonic shock alone.