Enhanced d-mannose production by rational engineering of cellobiose 2-Epimerase.

Simultaneous boosting of thermostability and glucose tolerance in engineered glucosidase through terminal modification.

Ionic liquids for biomacromolecule purification: from molecular interactions to practical applications.

Systems-level understanding of plant immune networks through single-cell and spatial omics.

Understanding the local lattice distortion in response to charge carriers is pivotal for understanding the mechanisms of electron-phonon coupling in halide perovskites. In this work, we present synergistic lattice softening and polaron engineering in Cu2+-doped Cs2SnCl6, revealing mechanisms through which dopant-induced structural perturbations suppress lattice thermal conductivity (κlat) while simultaneously enhancing electrical conductivity (σ). Systematic analysis via temperature-dependent Raman spectroscopy and thermal conductivity studies elucidated the mechanism of phonon scattering. The Cu2+ doping induces chloride vacancies that modulate lattice anharmonicity and acoustic phonon contributions (κa) through tensile-stress-induced reduced bond stiffness. Conversely, the charge transport via the small polaron hopping (SPH) mechanism governs that Cu2+ doping reduces charge carrier activation (Ehop) from 0.57 to 0.15 eV, facilitating superior electrical conductivity. Thus, rational dopant engineering in halide perovskites enhances the charge carrier, which offers a critical strategy for maximizing the thermoelectric figure of merit (zT).

The initiation of the classical complement pathway begins with the binding of the globular head of complement component 1q (C1q) to antigen-bound immunoglobulin M (IgM). To investigate the binding mechanism and sites of C1q, a single-chain protein mimetic of the globular head of C1q and variants thereof were designed. Two approaches were used to generate single-chain globular head C1q variants containing single point mutations potentially altering IgM/C1q binding. The rational protein engineering approach aimed to increase surface charge, considering the negatively charged IgM Cµ3 region and positively charged C1q globular heads. Further, a library of 646variants with single point mutations in the C1q B-chain loops was designed and expressed using yeast surface display. Three rounds of panning in IgM-coated plates yielded twenty-eight sequenced yeast colonies. The His-tagged wild type variant and six of nine selected variants were stably expressed in Chinese hamster ovary cells and purified using immobilized-metal affinity chromatography. All variants were tested for IgM interaction in competition with serum-derived C1q and in a complement activation assay to evaluate the C1q competition potential of the single-chain globular head proteins. Expression levels differed among the globular head C1q variants, and SDS-PAGE analysis revealed variations in migration mobility, suggesting conformational differences. Four variants showed enhanced IgM binding compared to the wild type variant indicated by improved C1q displacement in the competitive interaction assay. These results were further supported by an advanced complement activation assay, where these variants significantly inhibited complement activation. These findings underpin the critical role of specific amino acids for IgM/C1q interaction and highlight the potential of engineered C1q as a potent inhibitor or activator of the classical complement cascade.

An engineered imine reductase variant capable of synthesizing (S)-nicotine was developed through structure-guided directed evolution. Enzyme library screening identified IR-55 as an ideal parent, exhibiting high yield and good enantioselectivity. Targeted combinatorial mutagenesis of a crucial loop (residues 227-236) produced mutant M6 with 97.7% ee. By dynamically regulating the pH within the range of 7.5-8.0, a substrate loading of 250 g/L was achieved, resulting in a conversion rate of 94% after 4 h with space-time yield (STY) of 58.7 g/L/h. Scale-up with 2.5 g of substrate in 20 mL for 6 h yielded 1.23 g of product (97.2% ee, 75.9% isolated yield STY 10.3 g/L/h), demonstrating superior space-time yield and operational efficiency compared to existing biocatalytic routes. This work not only offers an efficient pathway for the industrial synthesis of (S)-nicotine through rational enzyme engineering but also provides a comprehensive strategy to overcome substrate inhibition and enzyme inactivation under high substrate concentration.

The in-situ upcycling of decentralized methane and nitrogen gas (N2)-derived ammonia via methanotrophic bacteria is highly attractive. However, the toxic intermediate generated from ammonia oxidation significantly inhibits cell growth, thereby hindering efficient bioproduction. Herein, by integrating transcriptomic analysis, we develop rational metabolic engineering strategies and an optimized fed-batch fermentation to enhance ammonia utilization in a methanotrophic bacterium of Methylotuvimicrobium sanxanigenens. The modified M. sanxanigenens overexpressing hydroxylamine reductase efficiently co-assimilates methane and ammonia for cell protein synthesis, with an 18-fold increase in productivity. The resulting methanotrophic cell protein (MCP) not only exhibits an ideal essential amino acid profile but also contains bioactive nutrients, including polysaccharides and peptides. Oral administration of this nutritional MCP significantly ameliorates colitis symptoms in male mice by attenuating inflammatory progression and restoring the intestinal barrier. Moreover, MCP treatment maintains gut microbiota homeostasis and promotes the excretion of beneficial metabolites, thereby protecting the intestinal microenvironment. Hence, this study provides a promising biological approach for the local bio-valorization of decentralized CH4 and air into functional feed additives. This biotechnology not only facilitates advancements in developing carbon-negative gas-to-value pathways but also drives green transformations in animal husbandry by reducing the use of antibiotics and vaccines.

Organic afterglow probes activated by X-rays hold considerable potential for deep-tissue imaging and cancer therapy. However, their applications are often limited by short-wavelength emission and the inefficient X-ray-induced generation of reactive oxygen species (ROS). To overcome these challenges, we developed a molecularly engineered small-molecule probe that integrates deep-tissue imaging through X-ray-triggered afterglow (AGL) in the second near-infrared (NIR-II) window. This system features a chemiexcitable phenoxy-adamantylidene donor linked to a rhodamine-based perchlorate acceptor via a vinyl bridge, forming a conjugated donor-π-acceptor (D-π-A) architecture. The extended π-conjugation and reduced excited-state energy of this framework enable efficient NIR-II emission (up to ∼1100 nm). Upon X-ray irradiation, the generated singlet oxygen (1O2) adds to the adamantylidene unit, and the resulting chemiexcitation transfers the released energy to the rhodamine perchlorate acceptor to produce an NIR-II afterglow. Meanwhile, the probe enables sustained singlet-oxygen production, synergistically enhancing tumor cell eradication while reducing the required radiation dose. This integrated molecular design establishes a unified platform for NIR-II afterglow-guided radiotheranostics, demonstrating the potential of rational molecular engineering to address the limitations of conventional X-ray-responsive agents and achieve spatiotemporally controlled cancer diagnosis and treatment.

Nickel oxide (NiOx) is among the most widely used hole-transport materials (HTMs) for inverted perovskite solar cells (PSCs), yet its substantial surface defects compromise the device's performance and long-term stability. Despite the development of various surface engineering strategies, the underlying mechanism governing interfacial dynamics is incompletely understood. Herein, we systematically investigate the structural roles of molecular passivators in tailoring NiOx properties, with a focus on elucidating the distinct mechanisms of two structurally analogous modifiers: the polymer polyvinylpyrrolidone (PVP) and the small-molecule N-methylpyrrolidone (NMP). The results demonstrate that the pronounced steric hindrance arising from the long polymer chains of PVP constructs a physical barrier, which detrimentally impacts charge transport and perovskite crystallization. Conversely, NMP capitalizes on its small molecular size and chemical reactivity to achieve directional selective passivation. This chemical modification not only effectively optimizes interfacial properties but also facilitates the crystallization of perovskite films. As a result, the NMP-modified PSCs achieve a power conversion efficiency (PCE) of 20.89%, in contrast to 18.52% for their PVP-modified counterparts. Notably, the unencapsulated NMP-modified device retains 93% of its initial efficiency following 1800 h of storage at 25 °C under a nitrogen atmosphere. This work sheds light on the intrinsic correlation between molecular structure and device performance, thereby offering valuable guidance for further optimization of both the efficiency and long-term stability of PSCs.

Real-time biochemical sensing is essential for precision medicine, yet current wearable and transdermal biosensors suffer from signal drift, calibration demands, and limited multiplexing capabilities in vivo. Here, we introduce digital fluorescent microneedles that translate analyte concentrations into scannable QR codes via threshold-activated probes. Each microneedle functions as a fluorescent binary switch, turning "on" only above a defined analyte threshold, thereby eliminating the need for calibration and enhancing robustness against tissue heterogeneity and environmental noise. The microneedles feature a biodegradable, mechanically optimized "baby-bottle" design that enables reliable skin penetration and controlled tip detachment. Central to this concept is the rational engineering of fluorescent probes with discrete activation thresholds, which-when embedded in microneedles-produce stepwise readouts spanning physiopathological ranges of pH (4.5-8.5) and glucose (1-10mM). By tuning probe loading, we achieve reproducible threshold activation, enabling fully digital, multiplexed detection of pH and glucose in skin with classification accuracies of 93% and 85%. This digital encoding concept is broadly extensible to diverse probes and biomarkers, providing a scalable route to calibration-free, multiplexed biosensing in vivo. The QR-based output delivers a direct, quantitative representation of biochemical information, facilitating decentralized diagnostics and integration into digital health workflows. Together, these advances establish digital microneedles as a versatile and clinically relevant platform for transdermal biosensing.

ABSTRACT Electrocatalytic technology represents a pivotal pathway for converting low‐value feedstocks into high‐value products, though its practical implementation continues to face fundamental challenges such as sluggish reaction kinetics and high energy barriers. These limitations are increasingly being overcome through multi‐active site (MAS) architectures, which utilize synergistic effects to facilitate multi‐electron transfer processes and establish a new paradigm in catalyst design. This review systematically explores rational design and engineering strategies for MAS structures, covering approaches such as heterostructure construction, dual‐atom site modulation, defect engineering, alloying, and cascade reaction systems, all aimed at improving overall electrocatalytic performance. We further analyze the intrinsic mechanisms responsible for performance breakthroughs in MAS architectures, including their ability to decouple reaction steps, optimize intermediate adsorption, enable electron–proton co‐transfer, and suppress competing side reactions. By integrating advanced characterization techniques with theoretical simulations, this work also reveals key cooperative mechanisms and dynamic reaction pathways, establishes a foundational framework for catalyst refinement, and details applications of multi‐component active sites across major catalytic reactions. Finally, we outline persistent challenges and propose future research directions, offering a systematic theoretical basis for the development of next‐generation electrocatalysts for sustainable energy systems.

Proton transfer (PT) kinetics through the electric double layer is a critical yet often overlooked bottleneck for acidic oxygen evolution reaction (OER) under industrially relevant high potential conditions. Herein, we propose an interfacial water microenvironment engineering strategy to address this challenge by constructing a CdO-Co3-x Cd x O4 heterostructure with a strong built-in electric field. Combined in situ ATR-SEIRAS, kinetic isotope effect (KIE) analysis, and ab initio molecular dynamics (AIMD) simulations reveal that the induced electric field effectively disrupts the rigid interfacial hydrogen-bond network, increasing the proportion of isolated water molecules. Crucially, this disordered water structure significantly lowers the energy barrier for water reorientation, thereby directly accelerating the rate-determining proton transfer kinetics. As a result, the catalyst exhibits an order-of-magnitude enhancement in intrinsic activity at 1.70 V vs. RHE compared to pure Co3O4. This work establishes the rational engineering of the interfacial H-bond network as a decisive strategy for overcoming the kinetic limitations of high-potential electrocatalysis.

ABSTRACT Heterogeneous photo(electro)catalysis involves sequential steps of photon absorption, charge separation, polaron formation, trapping, bulk and surface recombination, charge extraction, and surface catalysis. Among these, the formation and dynamics of polarons, quasiparticles resulting from strong electron‐lattice interactions, play a pivotal yet often underappreciated role. With ultrafast lifetimes ranging from femtoseconds to picoseconds, polarons are challenging to control, but they crucially influence photon absorption, charge carrier mobility, recombination rates, and catalytic reactivity. Recent advances in time‐resolved spectroscopy, scanning probe microscopy, and theoretical modeling have enabled direct observation and mechanistic interpretation of polaronic states in various photoactive semiconductors. This minireview aims to provide a comprehensive and pedagogical overview of polaron phenomena in heterogeneous photo(electro)catalysts, with a focus on how they affect key material functionalities. Special emphasis is placed on correlating material performance with polaron behavior through state‐of‐the‐art experimental characterization and modeling techniques. By highlighting mechanistic insights and unifying design principles, this minireview aims to guide the rational engineering of semiconductors with tailored polaronic properties for enhanced photo(electro)catalytic performance.

Benzylisoquinoline alkaloids (BIAs) represent a diverse class of plant-derived secondary metabolites with significant medicinal and agricultural values. N-methylation is a common structural feature influencing the BIA bioactivity and bioavailability. Here, we report the characterization and rational engineering of two novel BIA N-methyltransferases (NMTs), SyNMT1 and SyNMT2 from Stephania yunnanensis. Key residues governing substrate promiscuity and catalytic efficiency were identified (A216 / F217 in SyNMT1; E218 / L219 / L223 in SyNMT2). Notably, the SyNMT2-L219F variant was engineered into a specific BIA 6OMT, representing the first instance of functional conversion from N- to O-methylation. This strategy was further extended to PsCNMT from Papaver somniferum, where the E197A/L198F mutation altered its substrate specificity and enhanced catalytic efficiency, increasing the Kcat and Kcat/Km values by 1.22- and 1.07-fold, respectively. This work provides a blueprint for engineering both the substrate promiscuity and catalytic efficiency of BIA NMTs, enriching the enzymatic toolkit for producing medicinally and agriculturally relevant BIAs.

The electrochemical nitric oxide (NO) valorization strategy reconciles industrial emission mitigation with distributed ammonia (NH3) production, offering a dual solution for deteriorating urban air quality and fertilizer-deprived agricultural regions. Rational engineering of active sites constitutes the cornerstone for overcoming this catalytic bottleneck. Herein, we report a chemical etching-coordination strategy that enables the precise construction of hollow-architected high-entropy oxides (HEOs) with a nanoporous shell and customizable multimetallic compositions spanning quinary to decenary systems. Employing RuFeCoNiCuZnO as the first HEO catalyst for electrocatalytic low-concentration NO (1 vol %) reduction delivers record-breaking Faraday efficiency of 99.08% and 104.03 μg h-1 mgcat-1 production rate for NH3 synthesis, outperforming FeCoNiCuZnO and some reported catalysts. The Zn-NO battery with RuFeCoNiCuZnO achieves a power density of 1.18 mW cm-2 and an NH3 yield of 69.87 μg h-1 mgcat-1. Experimental results demonstrate that the incorporation of Ru modifies the electronic structure and enhances NO adsorption capacity of FeCoNiCuZnO, thereby promoting NO electroreduction. This work establishes a general method to engineer HEO nanostructures, whose unique configuration offers new possibilities in catalysis and energy conversion.

All-solid-state batteries (ASSBs) have attracted considerable attention as next-generation energy storage systems owing to their high energy density and safety. However, their performance is critically limited by insufficient solid-solid interfacial contact and severe chemomechanical degradation, particularly for micro-sized silicon (µSi) anodes that undergo large volume changes during cycling. In this study, we report an interfacially reinforced crosslinked binder (IRCB) designed to stabilize µSi anodes in ASSBs by simultaneously addressing mechanical integrity and interfacial stability. The IRCB is synthesized via a facile crosslinking reaction between 1,4-butanediol diglycidyl ether and ethylenediamine, forming a robust 3D polymer network. This crosslinked structure enhances mechanical constraint, maintains interparticle contact, and provides ether-rich domains that facilitate Li+ transport, while strong hydrogen bonding improves adhesion to µSi surfaces. As a result, carbon-free µSi anodes employing IRCB exhibit markedly improved electrochemical stability, delivering 90% capacity retention after 300 cycles at 1 C, compared with only 16% for conventional PVDF-based electrodes. Structural and interfacial analyses reveal that IRCB effectively mitigates particle displacement and suppresses interfacial degradation with sulfide solid electrolytes. This work demonstrates that rational binder engineering is a key enabler for achieving stable and high-performance µSi anodes in ASSBs.

Construction and analysis of a cell factory for terpenoid biosynthesis in Pichia pastoris via metabolic engineering and metabolomics.

Natural products provide privileged scaffolds for drug discovery, yet their stereochemical complexity often exceeds the limits of synthetic chemistry. Genome mining has emerged as a transformative strategy to uncover cryptic biosynthetic gene clusters and enzymes with noncanonical activities. Recent studies have revealed enzymes exhibiting unusual stereoselectivities, thereby expanding the enzymatic repertoire for constructing complex chiral architectures. Comparative analyses indicated that subtle variations in sequence and active-site environments produce diverse stereochemical outcomes across enzyme families. This review highlights representative examples of stereodivergent enzymes identified through genome- or sequence-guided approaches, emphasizing their substrate scope, catalytic mechanisms, and stereocontrol features. These advances not only deepen our mechanistic understanding of stereoselectivity but also lay the groundwork for rational enzyme engineering and the development of next-generation biocatalysts in pharmaceutical synthesis.

Rational proton engineering offers a powerful strategy for enhancing the hydrogen evolution reaction (HER) performance of single-atom catalysts (SACs). Notably, achieving concerted proton management across multiple reaction steps presents a highly efficient approach, yet it remains more challenging to implement than single-step regulation. Here, we propose a domino-type proton provision-conversion-spillover programming for Pt SACs in acidic HER, enabled by ultrathin porous nitrogen-doped carbon (main 1-2 atomic layers, sub-1nm) encapsulated TiN nanowires with tips as dual-support tip-platform (Pt-NC1@TiN NWs). Experimental and theoretical results demonstrate that this platform triggers tip-distance-spillover domino effects to drive a proton cascade throughout HER. Specifically, NC1@TiN nanotips induce tip-enhanced effect that promotes interfacial proton accessibility. Concurrently, the short-distance Pt/TiN vertical coupling optimizes electronic modulation of unsaturated Pt-N2 sites to enhance their intrinsic activity. Exposed TiN sites function as hydrogen spillover centers to facilitate H2 desorption. Consequently, Pt-NC1@TiN NWs achieve a superior Pt mass activity of 153.5 A/mgPt@-100mV, surpassing Pt/C by two orders of magnitude. Notably, it reaches 2 A/cm2 at low cell voltage of 1.75V and sustains stable operation at 1 A/cm2 for 1200h in proton exchange membrane water electrolyzer (PEMWE). This work indicates the potential of harnessing multi-step domino processes for advanced catalyst design.