Zhongguo Zhong Yao Za Zhi. 2026 Aug;51(16):4623-4633. doi: 10.19540/j.cnki.cjcmm.20260330.401.

ABSTRACT

Coumarins mainly include simple coumarins, furanocoumarins, and pyranocoumarins. These compounds exhibit diverse biological activities, including anticoagulant, antibacterial, antitumor, and antioxidant effects, and thus possess high value for drug development. At present, coumarins are mainly obtained through traditional plant extraction methods. In recent years, synthetic biology has emerged as a new approach for the sustainable production of natural products. This article reviews the pharmacological effects, biosynthetic pathways, and biomanufacturing methods of different types of coumarins. It focuses on strategies for improving coumarin production, including the application of enzyme engineering based on directed evolution to modify rate-limiting enzymes and thereby enhance catalytic efficiency; the use of metabolic engineering to remodel metabolic flux, strengthen precursor supply, and weaken competing pathways, allowing more carbon flux to be directed toward target products; and the optimization of fermentation parameters through fermentation engineering to improve the viability of engineered strains and increase the yield of target compounds. These studies provide important references for the green, efficient, and sustainable production of coumarins, and are conducive to promoting the development of new coumarin-based drugs.

PMID:42693015 | DOI:10.19540/j.cnki.cjcmm.20260330.401

ACS Nano. 2026 Sep 1;20(34):23893-23906. doi: 10.1021/acsnano.6c07948.

ABSTRACT

Direct solar-to-chemical conversion offers a compelling route to clean, dispatchable energy. Photosystem I (PSI), an evolutionarily optimized light-driven oxidoreductase, can be repurposed for solar-fuel production by coupling its photochemistry to catalytic interfaces. However, the molecular determinants that govern productive electron transfer to abiotic catalysts remain poorly understood. Here, we present molecular structures of active PSI-Pt nanoparticle (PtNP) biohybrids that reveal how protein architecture controls catalyst access, binding geometry, and photocatalytic efficiency. Removal of stromal subunits exposes the electron transfer chain and enables PtNP binding proximal to the FX cluster, demonstrating that steric occlusion limits access to native acceptor regions in PSI. In contrast, in trimeric PSI, PtNPs bind at multiple sites per monomer, but only a subset are positioned within electron transfer distance of terminal cofactors, resulting in a heterogeneous population of productive and nonproductive configurations. Structural analyses and molecular dynamics simulations define the interface topology, electrostatics, and cofactor-to-nanoparticle distances that govern catalyst binding and electron transfer. These results establish that catalytic inefficiency arises not only from intrinsic electron transfer constraints but also from the distribution of binding geometries imposed by the protein scaffold. Together, these findings provide a molecular framework linking protein structure to biohybrid function and define design principles for engineering PSI-based solar fuel systems and protein-nanomaterial interfaces for light-driven catalysis.

PMID:42689710 | DOI:10.1021/acsnano.6c07948

ACS Appl Bio Mater. 2026 Sep 2. doi: 10.1021/acsabm.6c00770. Online ahead of print.

ABSTRACT

Proteases cleave peptide bonds and generate shorter polypeptide products, finding broad applications. For applications in peptide sequencing, protein mapping, and production of bioactive polypeptides, control over where proteolysis initiates and how it proceeds is critical. Natural proteolytic selectivity primarily originates from local recognition of short amino-acid motifs. However, higher-order or regional selectivity (i.e., cleavage biased toward specific termini or domains) remains difficult even with sophisticated protein engineering or complex multi-enzyme, cascade proteolytic design. We recently reported that trypsin@Ca-BPDC preferentially cleaved the N-terminus of T4 phage lysozyme (T4L) [ACS Appl. Mater. Interfaces 2023, 15 (7), 8927-8936], indicating a promising alternative to introduce directional or regional proteolysis through enzyme immobilization via a unique MOF, Ca-BPDC. To confirm such preference, as a follow-up of that work, here, we extend the MOF-based immobilization to two commercial serine proteases (mixture products with unreported compositions). Our time-resolved electron paramagnetic resonance (EPR) shows that, despite differing or weakly defined selectivity in solution, both commercial proteases exhibit a consistent shift toward N-terminal cleavage of T4L upon immobilized in Ca-BPDC through co-crystallization. Control experiments indicate negligible adsorption of the substrate to the Ca-BPDC alone, suggesting that directional selectivity arises from the coupled MOF-protease environment rather than substrate-MOF interactions. These results indicate that Ca-BPDC may be able to impose an additional, material-derived layer of proteolytic selection on commercial serine proteases. Thus, it may offer a practical way for directional or programmable proteolysis without enzyme chemical or genetic modification. Our immobilization platform also offers a reusable matrix compatible with real-time mechanistic analysis. This approach opens opportunities for controlled peptide generation, proteolytic selectivity tuning, and design of programmable proteolytic bioreactors.

PMID:42690895 | DOI:10.1021/acsabm.6c00770

J Agric Food Chem. 2026 Sep 2;74(34):27168-27178. doi: 10.1021/acs.jafc.6c07461.

ABSTRACT

Rhamnosyltransferases are remarkable biocatalysts for the synthesis of rhamnosylated natural products with valuable physicochemical properties and bioactivities. However, their application is hindered by poor stability and low catalytic efficiency. Here, we achieved simultaneous enhancement of catalytic efficiency and stability of a 1,2-rhamnosyltransferase by a distal mutational engineering strategy. The variant M9 exhibited a 589.43-fold extension in half-life, a 2.5 °C increase in Tm, a 13.6 °C increase in T50, and an 8- to 763-fold increase in activity toward diverse flavonoids compared with the wild type. Molecular dynamics simulations provided insights into enhanced thermostability and catalytic efficiency. To demonstrate its synthetic utility, a whole-cell biocatalytic system was constructed in E. coli by coexpressing M9 and UDP-rhamnose synthase, enabling a neohesperidin titer of 1.14 g L-1 without exogenous sugar donor supplementation. This study presents a practical enzyme engineering strategy for simultaneous activity-stability enhancement in glycosyltransferases and provides a promising biocatalyst for rhamnosylated natural product biosynthesis.

PMID:42690770 | DOI:10.1021/acs.jafc.6c07461

ACS Appl Mater Interfaces. 2026 Sep 1. doi: 10.1021/acsami.6c11728. Online ahead of print.

ABSTRACT

Pigments are widely utilized in industries; however, conventional synthetic pigment production relies on petroleum-based feedstocks, consumes significant energy, and involves toxic chemicals. Although natural pigments provide a sustainable alternative, these systems are constrained by seasonal variability, geographical dependence, and limited scalability. To overcome these limitations, we present a whole-cell biocatalytic approach for melanin synthesis and deposition, wherein recombinant Escherichia coli expressing tyrosinase is employed to convert l-tyrosine into melanin through copper-dependent oxidative polymerization. By harnessing intact microbial cells as self-contained biocatalytic units, this system bypasses the need for enzyme extraction and purification. The process conditions were systematically optimized to maximize melanin yield prior to in situ application on various surfaces, including fabric (cotton) and wood. The successful deposition of melanin was confirmed by ultraviolet-visible-near-infrared reflectance and transmittance measurements, wherein the coated cotton exhibited significantly lower reflectance and transmittance than the uncoated cotton, consistent with the formation of a light-absorbing melanin coating. The uncoated and coated cotton samples were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) to evaluate surface morphology and chemical modifications. SEM images of the uncoated cotton revealed cylindrical fibers in a bundled architecture, whereas the coated cotton exhibited a clear adherence of cells to the surface of the fibers. FTIR spectra showed similar characteristic cellulose peaks for both the uncoated and coated cotton, suggesting minimal changes after coating. XPS analysis indicated the presence of an additional N 1s peak, attributable to the biomacromolecules associated with the adhered bacterial cells. Finally, functional evaluation revealed that the coated cotton exhibited superior photothermal conversion properties, achieving a temperature rise of up to 71 °C under near-infrared laser irradiation compared to minimal heating in uncoated controls. To demonstrate the versatility of the platform, the coating strategy was further extended to wood, where similarly effective melanin deposition was achieved. Taken together, this work establishes a simplified, efficient, and potentially scalable route toward sustainable coloration through living whole-cell engineered biocatalysis.

PMID:42689727 | DOI:10.1021/acsami.6c11728

Langmuir. 2026 Sep 1;42(34):25110-25120. doi: 10.1021/acs.langmuir.6c03108.

ABSTRACT

Biodesulfurization offers an energy-efficient alternative to conventional hydrodesulfurization, but its industrial efficiency is severely bottlenecked by the low bioaccessibility of hydrophobic substrates across the oil-water interface. Here, we addressed this mass-transfer challenge using exogenous-surfactant-free water-in-oil Pickering emulsions stabilized solely by Gordonia sp. WQ-01A cells. Exploiting the strain’s native surface hydrophobicity (contact angle > 111°), the bacterial cells spontaneously assembled at the phase boundary to form a protective “bio-armor” without the aid of artificial barriers. Structural optimization indicated that an oil-to-water ratio of 1:4 and a cell loading of 10 g/L maximized the specific interfacial area with uniform droplets, governed by a limited coalescence mechanism that reached physical saturation at 20 g/L. Apparent kinetic modeling demonstrated a transition from a mass-transfer-limited regime to a pseudohomogeneous reaction regime, characterized by a significantly reduced apparent Michaelis constant Kmapp of 0.25 mmol/L and a maximum specific reaction rate Vmaxappof 9.96 mmol/kg-DCW/h. Consequently, the specific desulfurization rate was enhanced 3-fold to 5.17 mmol/kg-DCW/h compared to conventional aqueous systems, while maintaining over 90% activity across four consecutive 48-h cycles. This carrier-free strategy offers a practical, mechanically robust template for intensifying interfacial mass transfer in multiphase biocatalysis.

PMID:42689678 | DOI:10.1021/acs.langmuir.6c03108

J Biotechnol. 2026 Aug 7;419:58-69. doi: 10.1016/j.jbiotec.2026.08.002. Online ahead of print.

ABSTRACT

Vanadium-dependent haloperoxidases are enzymes found in bacteria, fungi and red or brown macroalgae. They are used as a defense system for the latter by producing bromoform. The intermediate product, HOBr or HOCl, is also a microbicidal compound that can be exploited in many domains as medical tools or disinfectant sprays for example. We show that the mutation identified in Ohshiro’s work, which alters substrate specificity toward chloride, is transferable to the homologous enzyme from Chondrus crispus. We then applied genetic and enzymatic engineering to design a chimera with glucose oxidase, thereby enhancing antimicrobial properties by providing a local source of H₂O₂. We used the SpyTag/SpyCatcher technology to form the chimera and obtained homogenous objects, indicating that one oligomeric form is favored. We demonstrated the release of HOBr and HOCl thanks to NADH that reacts spontaneously with it outside the active site of the enzyme. We also measured the steady-state kinetic parameters of the wild-type or modified enzymes. The formation of the chimera increased the specificity of ccVHPO1 inside the chimera, towards KBr or H₂O₂, compared to the enzyme alone with the SpyCatcher. Finally, we showed a significant increase in the microbicidal effect between a coupled enzymatic system with the glucose oxidase (the two enzymes are free in solution) compared to the chimera system, which is completely bactericidal at concentrations around 20 nM.

PMID:42567274 | DOI:10.1016/j.jbiotec.2026.08.002

J Biotechnol. 2026 Aug 7;419:58-69. doi: 10.1016/j.jbiotec.2026.08.002. Online ahead of print.

ABSTRACT

Vanadium-dependent haloperoxidases are enzymes found in bacteria, fungi and red or brown macroalgae. They are used as a defense system for the latter by producing bromoform. The intermediate product, HOBr or HOCl, is also a microbicidal compound that can be exploited in many domains as medical tools or disinfectant sprays for example. We show that the mutation identified in Ohshiro’s work, which alters substrate specificity toward chloride, is transferable to the homologous enzyme from Chondrus crispus. We then applied genetic and enzymatic engineering to design a chimera with glucose oxidase, thereby enhancing antimicrobial properties by providing a local source of H₂O₂. We used the SpyTag/SpyCatcher technology to form the chimera and obtained homogenous objects, indicating that one oligomeric form is favored. We demonstrated the release of HOBr and HOCl thanks to NADH that reacts spontaneously with it outside the active site of the enzyme. We also measured the steady-state kinetic parameters of the wild-type or modified enzymes. The formation of the chimera increased the specificity of ccVHPO1 inside the chimera, towards KBr or H₂O₂, compared to the enzyme alone with the SpyCatcher. Finally, we showed a significant increase in the microbicidal effect between a coupled enzymatic system with the glucose oxidase (the two enzymes are free in solution) compared to the chimera system, which is completely bactericidal at concentrations around 20 nM.

PMID:42567274 | DOI:10.1016/j.jbiotec.2026.08.002

J Biotechnol. 2026 Aug 7;419:58-69. doi: 10.1016/j.jbiotec.2026.08.002. Online ahead of print.

ABSTRACT

Vanadium-dependent haloperoxidases are enzymes found in bacteria, fungi and red or brown macroalgae. They are used as a defense system for the latter by producing bromoform. The intermediate product, HOBr or HOCl, is also a microbicidal compound that can be exploited in many domains as medical tools or disinfectant sprays for example. We show that the mutation identified in Ohshiro’s work, which alters substrate specificity toward chloride, is transferable to the homologous enzyme from Chondrus crispus. We then applied genetic and enzymatic engineering to design a chimera with glucose oxidase, thereby enhancing antimicrobial properties by providing a local source of H₂O₂. We used the SpyTag/SpyCatcher technology to form the chimera and obtained homogenous objects, indicating that one oligomeric form is favored. We demonstrated the release of HOBr and HOCl thanks to NADH that reacts spontaneously with it outside the active site of the enzyme. We also measured the steady-state kinetic parameters of the wild-type or modified enzymes. The formation of the chimera increased the specificity of ccVHPO1 inside the chimera, towards KBr or H₂O₂, compared to the enzyme alone with the SpyCatcher. Finally, we showed a significant increase in the microbicidal effect between a coupled enzymatic system with the glucose oxidase (the two enzymes are free in solution) compared to the chimera system, which is completely bactericidal at concentrations around 20 nM.

PMID:42567274 | DOI:10.1016/j.jbiotec.2026.08.002

J Biotechnol. 2026 Aug 7;419:58-69. doi: 10.1016/j.jbiotec.2026.08.002. Online ahead of print.

ABSTRACT

Vanadium-dependent haloperoxidases are enzymes found in bacteria, fungi and red or brown macroalgae. They are used as a defense system for the latter by producing bromoform. The intermediate product, HOBr or HOCl, is also a microbicidal compound that can be exploited in many domains as medical tools or disinfectant sprays for example. We show that the mutation identified in Ohshiro’s work, which alters substrate specificity toward chloride, is transferable to the homologous enzyme from Chondrus crispus. We then applied genetic and enzymatic engineering to design a chimera with glucose oxidase, thereby enhancing antimicrobial properties by providing a local source of H₂O₂. We used the SpyTag/SpyCatcher technology to form the chimera and obtained homogenous objects, indicating that one oligomeric form is favored. We demonstrated the release of HOBr and HOCl thanks to NADH that reacts spontaneously with it outside the active site of the enzyme. We also measured the steady-state kinetic parameters of the wild-type or modified enzymes. The formation of the chimera increased the specificity of ccVHPO1 inside the chimera, towards KBr or H₂O₂, compared to the enzyme alone with the SpyCatcher. Finally, we showed a significant increase in the microbicidal effect between a coupled enzymatic system with the glucose oxidase (the two enzymes are free in solution) compared to the chimera system, which is completely bactericidal at concentrations around 20 nM.

PMID:42567274 | DOI:10.1016/j.jbiotec.2026.08.002