Activation of the voltage-Gated Potassium channels by Amphiphilic Glycopeptides.

Voltage-gated ion channels (VGICs) are allosterically modulated by glycosaminoglycan proteoglycans and sialic acid glycans. However, the structural diversity and heterogeneity of these biomolecules pose significant challenges to precisely delineate their underlying structure-activity relationships. Herein, we demonstrate how heparan sulfate (HS) and sialic acid synthetic glycans appended on amphiphilic glycopeptide backbone influence cell membrane persistence and modulate the gating of the Kv2.

Spin-Frustrated Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) are a fascinating class of structured materials with diverse functionality originating from the distinctive physicochemical properties. This review focuses on the specific chemical design of geometrically frustrated MOFs along with the origin of the intriguing magnetic properties. We have discussed the arrangement of spin centres (metal and ligand) which are responsible for the unusual magnetic phenomena in MOFs.

Access to Bis-Silylene-Stabilized Group 13 Cations.

Herein, we report the isolation of pyridine moiety-functionalized SiNSi pincer-based bis-silylene ligand () and its reactivity toward various halide precursors (X = Br and I) of group 13 elements (M = Al, Ga, and In). This gave us straightforward access to the SiNSi pincer-coordinated group 13 cations (-). These complexes are duly characterized by single-crystal X-ray diffraction studies, multinuclear magnetic resonance spectroscopy (H, C, and Si), and high-resolution mass spectrometry techniques.

EARTH-ABUNDANT 3d-TRANSITION METAL METASILICATES AS EFFECTIVE ELECTROCATALYSTS FOR ALKALINE HER: CuZnSiO3 OUTPERFORMS CuSiO3 AND ZnSiO3.

Hydrogen evolution reaction (HER) is a key reaction in electrochemical water splitting for hydrogen production leading to the development of potentially sustainable energy technology. Importantly, the catalysts required for HER must be earth-abundant for their large-scale deployment; silicates representing one such class. Herein, we have synthesized a series of transition mono- and bi- metal metasilicates (with SO32- group) using facile wet-chemical method followed by calcination at a higher temperature.

AlphaMut: A Deep Reinforcement Learning Model to Suggest Helix-Disrupting Mutations.

Helices are important secondary structural motifs within proteins and are pivotal in numerous physiological processes. While amino acids (AA) such as alanine and leucine are known to promote helix formation, proline and glycine disfavor it. Helical structure formation, however, also depends on its environment, and hence, prior prediction of a mutational effect on a helical structure is difficult.

Highly Sensitive Naphthalene-Based Twisted Intramolecular Charge Transfer Molecules for the Detection of In Vitro and In Cellulo Protein Aggregates.

Newly synthesized naphthalene-based twisted intramolecular charge transfer (TICT) molecules show 8.5- and 2.6-fold increases in fluorescence intensity upon binding with protein aggregates in comparison with the fluorescence enhancement for thioflavin T (ThT).

Dynamic regulation of ion transport through a bis(1,3-propanediol)-based channel allosteric azobenzene photoswitching.

The transportation of ions across cell membranes is vital in biological functions and is frequently controlled by external triggers like light, ligands, and voltage. Synthetic ion transport systems, particularly those featuring gating mechanisms, have attracted considerable interest. In this research, we engineered self-assembled barrel rosette ion channels using a photoresponsive azobenzene integrated at an allosteric site.

[Au]/[Ag]-Catalyzed Glycosidation of Ethynylcyclohexyl Glycosyl Carbonates Enables Direct Stereoselective Synthesis of 2-Azido-2-deoxy-β-mannopyranosides.

We describe the [Au]/[Ag]-catalyzed activation of ethynylcyclohexyl 2-azido-4,6--benzylidene mannosyl carbonates for β-mannosamine linkage preparation in high yield and selectivity in a temperature- and concentration-dependent manner. VT-NMR studies reveal an anomeric triflate intermediate generated in the absence of an acceptor alcohol that is stable up to -10 °C. The generality of the protocol was illustrated by successful application to a series of acceptors and by synthesis of a fully protected type 19F capsular trisaccharide.

Effect of a single water molecule on the conformational preferences of a capped Pro-Gly dipeptide in the gas phase.

Herein, we have investigated the effect of microhydration on the secondary structure of a capped dipeptide Boc-DPro-Gly-NHBn-OMe (Boc = tert-butyloxycarbonyl, Bn = Benzyl), i.e., Pro-Gly (PG) with a single H2O molecule using gas-phase laser spectroscopy combined with quantum chemistry calculations.

Apoptosis-Inducing Activity of a 2-Hydroxyphenyl Benzamide-Based Self-Assembled Anion Channel.

Despite the significant interest in designing artificial ion channels, there is limited availability of channel-forming molecules to tackle complex issues, especially in biological systems. Moreover, a major challenge is the scarcity of chloride transporters that can selectively induce toxicity in cancer cells while minimizing harm to normal healthy cells. This work reports a series of 2-hydroxyphenyl benzamide-based small molecules 1 a-1 c, which self-assemble to form barrel rosette-type artificial ion channels that adequately transport chloride ions across membranes.

C2-Linked Arabinose-Functionalized Polystyrene Microbeads Selectively Target .

Carbohydrates play pivotal roles in the first stages of microbial infections and can be exploited as decoys to hijack the interactions between bacteria and the host cell. Multivalent glycan probes mimicking the natural presentation of glycans in living cells have been successfully employed to study fundamental carbohydrate/protein interactions in microbial systems; however, most pathogenic glycan receptors exhibit a shared specificity for commonly found sugars present in both healthy and pathogenic cells, posing a challenge for target selectivity. In this study, we report the synthesis of a small library of d-arabinose multivalent probes, a sugar absent in human physiology, and their evaluation in a bacteria agglutination assay using cluster analysis.

A stochastic field theory for the evolution of quantitative traits in finite populations.

Infinitely many distinct trait values may arise in populations bearing quantitative traits, and modeling their population dynamics is thus a formidable task. While classical models assume fixed or infinite population size, models in which the total population size fluctuates due to demographic noise in births and deaths can behave qualitatively differently from constant or infinite population models due to density-dependent dynamics. In this paper, I present a stochastic field theory for the eco-evolutionary dynamics of finite populations bearing one-dimensional quantitative traits.

NeoMProbe: a new class of fluorescent cellular and tissue membrane probe.

The development of long-lasting plasma membrane (PM) and basement membrane (BM) probes is in high demand to advance our understanding of membrane dynamics during differentiation and disease conditions. Herein, we report that the microheterogeneity of heparan sulfate (HS) on fluorescent neo-proteoglycans backbone offers a facile platform for designing membrane probes. Confocal live-cell imaging studies of cancer and normal cell lines with a panel of Cy5 fluorescently tagged neo-proteoglycans confirmed that highly sulfated HS ligands with an l-iduronic acid component (PG@ID-6) induce a prolonged and brighter expression on the PM compared to low-sulfated and uronic acid counterparts.

Phenacylselenoesters allow facile selenium transfer and hydrogen selenide generation.

Hydrogen selenide (HSe) is a precursor to several selenium-containing biomolecules and is emerging as an important redox-active species in biology, with yet to be completely characterized roles. Tools that reliably generate HSe are key to achieving a better understanding of selenium biology. Here, we report the design, synthesis and evaluation of phenacylselenoesters as sources of HSe.

Rigidifying the β2-α2 Loop in the Mouse Prion Protein Slows down Formation of Misfolded Oligomers.

Transmissible Spongiform Encephalopathies are fatal neurodegenerative diseases caused by the misfolding of the cellular prion protein (PrP) into its pathological isoform (PrP). Efficient transmission of PrP occurs within the same species, but a species barrier limits interspecies transmission. While PrP structure is largely conserved among mammals, variations at the β2-α2 loop are observed, and even minor changes in the amino acid sequence of the β2-α2 loop can significantly affect transmission efficiency.

[Au]/[Ag]-catalysed synthesis of non-hydrolysable -glycosides.

Many -glycosides are found in natural products, drugs and small molecular probes. Herein, we report the synthesis of -glycosides by the [Au]/[Ag]-catalysed activation of ethynylcyclohexyl glycosyl carbonate donors. This mild, catalytic, fast and high yielding protocol enables the synthesis of a diverse array of -glycosides that were otherwise challenging to synthesize.

Evaluating tree-ring proxies for representing the ecosystem productivity in India.

Terrestrial ecosystems are one of the major sinks of atmospheric CO and play a key role in climate change mitigation. Forest ecosystems offset nearly 25% of the global annual CO emissions, and a large part of this is stored in the aboveground woody biomass. Several studies have focused on understanding the carbon sequestration processes in forest ecosystems and their response to climate change using the eddy covariance (EC) technique and remotely sensed vegetation indices.

N-Heterocyclic Silylene-Cu(I) Complexes as Efficient Catalysts for Three-Component Coupling Reactions.

We have explored NHSi-supported copper(I) complexes as active and highly efficient catalysts for A (aldehyde-alkyne-amine) and KA (ketone-alkyne-amine) three-component coupling reactions to synthesize propargyl amines in excellent yields with high TOF under solvent-and additive-free conditions.

UiO-67 MOF-Encapsulated NHC-Based Single-Site Copper Catalyst and Its Application in Regioselective Borylation of Terminal Alkynes.

N-Heterocyclic carbenes (NHCs) act as versatile ligand backbones due to their strong σ-donation and π-acceptance properties. However, the encapsulation of NHC-coinage metal complexes in a metal-organic framework (MOF) to utilize them in organic catalysis is rare. In this work, an NHC-coordinated CuBr (NHC = BnIm; 1,3-dibenzyl-imidazol-2-ylidene) complex was encapsulated in UiO-67 MOF ((BnIm)CuBr@UiO-67) and further utilized toward the regioselective protoboration of terminal alkynes.

Acylhydrazone-based reversibly photoswitchable ion pair transporter with OFF-ON cotransport activity.

The cellular membrane transport of physiologically important cations and anions is omnipresent and regulates different physiological functions. Whereas a notable number of cation-anion transporters are being developed to transport salts across the membrane, developing an artificial cation-anion symporter with stimulus-responsive activities is an immense obstacle. Herein, for the first time, we report reversibly photoswitchable acylhydrazone-based transporter 2 that has distinctive OFF-ON cation-anion co-transport abilities.

Anomalous lattice contraction and emerging topological phases in Bi-substituted SmIrO.

We demonstrate that substituting Bi for Sm in the pyrochlore Sm$_2$Ir$_2$O$_7$ induces an anomalous lattice contraction, with $\Delta a \sim -0.012$~\AA~observed at 10\% Bi substitution, where 'a' denotes the lattice constant. Beyond 10\% Bi substitution, the lattice expands according to Vegard's law.

Photo-activation of Tolane-based Synthetic Ion Channel for Transmembrane Chloride Transport.

While natural channels respond to external stimuli to regulate ion concentration across cell membranes, creating a synthetic version remains challenging. Here, we present a photo-responsive uncaging technique within an artificial ion channel system, which activates the ion transport process from a transport-inactive o-nitrobenzyl-based caged system. From the comparative ion transport screening, 1 b emerged as the most active transporter.