Catalytic Function Research Articles

Water Migration through Enzyme Tunnels Is Sensitive to the Choice of Explicit Water Model.

The utilization of tunnels and water transport within enzymes is crucial for their catalytic function as water molecules can stabilize bound substrates and help with unbinding processes of products and inhibitors. Since the choice of water models for molecular dynamics simulations was shown to determine the accuracy of various calculated properties of the bulk solvent and solvated proteins, we have investigated if and to what extent water transport through the enzyme tunnels depends on the selection of the water model. Here, we focused on simulating enzymes with various well-defined tunnel geometries. In a systematic investigation using haloalkane dehalogenase as a model system, we focused on the well-established TIP3P, OPC, and TIP4P-Ew water models to explore their impact on the use of tunnels for water molecule transport. The TIP3P water model showed significantly faster migration, resulting in the transport of approximately 2.5 times more water molecules compared to that of the OPC and 1.7 times greater than that of the TIP4P-Ew. Finally, the transport was 1.4-fold more pronounced in TIP4P-Ew than in OPC. The increase in migration of TIP3P water molecules was mainly due to faster transit times through dehalogenase tunnels. We observed similar behavior in two different enzymes with buried active sites and different tunnel network topologies, i.e., alditol oxidase and cytochrome P450, indicating that our findings are likely not restricted to a particular enzyme family. Overall, this study showcases the critical importance of water models in comprehending the use of enzyme tunnels for small molecule transport. Given the significant role of water availability in various stages of the catalytic cycle and the solvation of substrates, products, and drugs, choosing an appropriate water model may be crucial for accurate simulations of complex enzymatic reactions, rational enzyme design, and predicting drug residence times.

Graph theory approaches for molecular dynamics simulations.

Graph theory, a branch of mathematics that focuses on the study of graphs (networks of nodes and edges), provides a robust framework for analysing the structural and functional properties of biomolecules. By leveraging molecular dynamics (MD) simulations, atoms or groups of atoms can be represented as nodes, while their dynamic interactions are depicted as edges. This network-based approach facilitates the characterization of properties such as connectivity, centrality, and modularity, which are essential for understanding the behaviour of molecular systems. This review details the application and development of graph theory-based models in studying biomolecular systems. We introduce key concepts in graph theory and demonstrate their practical applications, illustrating how innovative graph theory approaches can be employed to design biomolecular systems with enhanced functionality. Specifically, we explore the integration of graph theoretical methods with MD simulations to gain deeper insights into complex biological phenomena, such as allosteric regulation, conformational dynamics, and catalytic functions. Ultimately, graph theory has proven to be a powerful tool in the field of molecular dynamics, offering valuable insights into the structural properties, dynamics, and interactions of molecular systems. This review establishes a foundation for using graph theory in molecular design and engineering, highlighting its potential to transform the field and drive advancements in the understanding and manipulation of biomolecular systems.

Molecular basis for the diversification of lincosamide biosynthesis by pyridoxal phosphate-dependent enzymes.

The biosynthesis of the lincosamide antibiotics lincomycin A and celesticetin involves the pyridoxal-5'-phosphate (PLP)-dependent enzymes LmbF and CcbF, which are responsible for bifurcation of the biosynthetic pathways. Despite recognizing the same S-glycosyl-L-cysteine structure of the substrates, LmbF catalyses thiol formation through β-elimination, whereas CcbF produces S-acetaldehyde through decarboxylation-coupled oxidative deamination. The structural basis for the diversification mechanism remains largely unexplored. Here we conduct structure-function analyses of LmbF and CcbF. X-ray crystal structures, docking and molecular dynamics simulations reveal that active-site aromatic residues play important roles in controlling the substrate binding mode and the reaction outcome. Furthermore, the reaction selectivity and oxygen-utilization of LmbF and CcbF were rationally engineered through structure- and calculation-based mutagenesis. Thus, the catalytic function of CcbF was switched to that of LmbF, and, remarkably, both LmbF and CcbF variants gained the oxidative-amidation activity to produce an unnatural S-acetamide derivative of lincosamide.

Effect of High Voltage Electrode Material on Methanol Synthesis in a Pulsed Dielectric Barrier Discharge Plasma Reactor

Plasma methanol synthesis from captured CO2 and renewable H2 is one of the most promising technologies that can drastically lower the carbon footprint in methanol production, but the associated high energy costs make it less competitive. Herein, we investigated the impact of the high-voltage electrode configuration on methanol formation. The effect of electrode materials Cu, Al, and stainless steel (SS) SUS304 on CO2 hydrogenation to methanol using a temperature-controlled pulsed dielectric barrier discharge (DBD) plasma reactor was examined. The electrode surface area (ESA) was varied from 157 mm2 to 628 mm2 to determine the effect on discharge characteristics and the overall influence of plasma surface reactions on methanol production. The Cu electrode showed superior methanol synthesis performance (0.14 mmol/kWh) which was attributed to its catalytic activity function, while the Al electrode had the least production (0.08 mmol/kWh) ascribed to the excessive oxide coating on its surface, passivating its ability to promote methanol synthesis chemical reactions. In all electrode materials, the highest methanol production was achieved at 157 mm2 ESA at a constant applied voltage. Lastly, the plasma charge concentration per discharge volume was determined to be an important parameter in fine-tuning the DBD reactor to enhance methanol synthesis.

Synergistic role of Rubisco inhibitor release and degradation inphotosynthesis.

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) exhibits catalytic promiscuity, resulting in error-prone reactions and the formation of inhibitory sugar phosphates. Specifically, Xylulose-1,5-bisphosphate (XuBP) acts as an inhibitor by binding to the active site of Rubisco, thereby impairing its catalytic function. Thermolabile Rubisco activase (Rca) facilitates the release of such inhibitors, including XuBP, by remodelling Rubisco. In Arabidopsis thaliana, the phosphatase pair CbbYA and CbbYB subsequently hydrolyses XuBP to prevent its rebinding to Rubisco. To explore the functional interplay between these components in maintaining photosynthesis, cbbya, cbbyb and cbbyab mutants were crossed with RCA knockdown (rca-2) lines. Additionally, both RCA and CBBYA were overexpressed in wild-type (WT) Arabidopsis thaliana. Phenotypic analyses revealed an exacerbation in decreased growth and photosynthetic efficiency in the cbbyab rca-2 double mutants compared with the control mutants (cbbyab and rca-2), indicating a negative genetic interaction. Furthermore, the co-overexpression of RCA and CBBYA did not improve photosynthesis under short-term heat stress, and light reactions were adversely affected relative to the WT. These findings illustrate the synergistic roles of Rca, CbbYA and CbbYB in maintaining carbon fixation and promoting plant growth in Arabidopsis thaliana. Thus, the coordinated regulation of Rca and CbbY enzymes is crucial for optimizing photosynthetic efficiency.

Eco‐Friendly Self‐Adaptive Catalytic Strategy for Plastics Lifecycles: Achieving Green Preparation, Superior Flame Retardancy, and Self‐Driven Sustainability

AbstractSemi‐rigid polyurethane foams (SPUF) with high deformation resistance and strength are indispensable for cushioning applications. However, for high fire risk and cascaded pollutant effects, overused multifarious additives and foam wastes exacerbate global environmental concerns. One option to address this issue is to develop eco‐friendly multifunctional flame retardants that participate in the material lifecycles of preparation, safe service, waste management, and sustainable recycling. Herein, a novel self‐adaptive catalytic strategy is reported that exploits the temperature and agent structure‐responsive catalytic ability of eco‐friendly sodium propionate (SP), reconciling the often‐conflicting properties of fabrication and recycling while effectively mitigating combustion risks and additive pollution. The adaptive catalytic function of SP impressively involves all aspects of foam life cycles: 1) catalyzing foaming without complex/hazardous catalysts; 2) providing superior flame‐retardant efficiency with a high limiting oxygen index of 25.5% without relying on traditional flame retardants; 3) promoting in situ network fragmentation and reorganization into strong adhesives (5.8 MPa); and 4) further recycling of the newly formed adhesives in a self‐driven sustainable manner. A novel green strategy is presented that addresses fire hazards, plastic pollution, and the unsustainability of recycling, minimizing the ecological risks of foam, which will positively impact future sustainable material design involving diverse additives.

Moisture‐Resistant Nanofiber Membrane Loaded with Copper‐Manganese‐Tin Oxides for Dust and CO Filtration in High Humidity Environments

AbstractThis study presents a novel protective membrane, (0.8MnCuSnOx‐NaCl)@M, designed for high‐efficiency filtration of dust particles and carbon monoxide (CO) gas offers superior moisture resistance, air permeability, and catalytic functionality in high‐humidity underground settings. The membrane, incorporating tin oxide‐doped CuMnOx into polyvinylidene fluoride (PVDF) fibers with sodium chloride (NaCl), achieves 99.99% air filtration efficiency, 323.68 mm s−1 air permeability, and 92.5% CO catalytic filtration efficiency. Concurrently, the membrane exhibited exceptional hydrophobicity, characterized by a substantial water contact angle of 116.7°, negligible water staining, and a high hydrostatic pressure rating of 2035 Pa, suitable for humid environments. Furthermore, the water absorption profile of the membrane featured a diminished hydroxyl vibrational band, accompanied by a sustained CO conversion efficiency, attesting to its resistance to moisture‐induced deterioration. Computational fluid dynamics (CFD) simulations further clarify the membrane's filtration mechanism, indicating its potential for selective CO and particle filtration. This study provides a reliable idea for the development of moisture‐resistant fiber membranes with high efficiency for filtration of dust and CO. and underscores the synergy of experimental and theoretical approaches.

Molecular insights into the aspartate protease Plasmepsin II activity inhibition by fluoroquinolones: A pathway to antimalarial drug development

Plasmepsin II (PlmII) belongs to the aspartate proteases and is involved in hemoglobin degradation in Plasmodium falciparum. Due to its critical role in the survival of the Plasmodium, PlmII is considered as a potent drug target for antimalarial therapy. We have done recombinant protein production of pro-plasmepsin II (Pro-plmII). Pro-PlmII was further activated to mature form (mPlmII) and its activity was confirmed by enzyme kinetics studies. The fluorescence spectroscopic and isothermal titration calorimetric studies show that fluoroquinolone-based antibiotic drugs norfloxacin, ciprofloxacin, and sparfloxacin bind with mPlmII. Molecular docking results show that only norfloxacin and ciprofloxacin are able to bind at the active site of mPlmII via hydrogen binding and hydrophobic interactions. Enzyme kinetics analysis reveals that norfloxacin and ciprofloxacin effectively inhibit mPlmII activity, while sparfloxacin does not exhibit any inhibitory effect on the enzyme's catalytic function. The two methyl groups on the 3rd and 5th carbon atoms of the piperazine ring make sparfloxacin unable to go inside mPlmII and bind at its active site. Overall, the results here suggested that fluoroquinolone-based antibiotic drugs norfloxacin, and ciprofloxacin, can be repurposed as antimalarial inhibitors targeting aspartic proteases. These findings contribute to pave the way for potential therapeutic interventions targeted at malaria.

Visualize PIM-1 Protein Function and Its Interaction With PI3K/Akt/mTOR Pathway Regulated by Its Active Sites Through FRET Biosensors.

Pro-viral Insertion site for the Moloney Murine Leukemia virus 1 (PIM-1) is widely involved in various biological processes and diseases, which is based on its structure and functional sites. However, the relationship between active sites and function of PIM-1 kinase remains unclear due to the lack of effective study approaches in live cells. Herein, to visualize the effect of different active sites in PIM-1 protein on its function activity and relation with PI3K/Akt/mTOR pathway, three mutant probes of EPHY which was developed previously based on fluorescence resonance energy transfer (FRET) technology to detect PIM-1 kinase activity in living cells were further constructed and transfected into cells followed by treating with PIM-1 inhibitors, ATP and PI3K inhibitor, respectively. The results showed that Lys67 is related to substrate binding and catalytic activity of PIM-1 kinase, thereby directly regulating PI3K/Akt/mTOR signaling pathway. Pro81/Asn82 are primarily participated in PIM-1 binding to ATP, thus also involving in the modulation on PI3K/Akt/mTOR signaling pathway, but play less role in the interaction between PIM-1 protein and its substrate. Asp167 has few effects on both the catalytic function activity of PIM-1 and PI3K/AKT/mTOR pathway, even though the binding ability of PIM-1 protein to its substrate is dramatically inhibited by D167A mutation. Altogether, the mutant probes works well as visualization tools to unearth the function of active sites in PIM-1 kinase, not only facilitating the further clarification of molecular mechanism underlying PIM-1 related signaling pathways, but also shedding light on drug development and disease therapy targeting PIM-1 protein.

The potential inhibitory mechanism of EGCG against the Chikungunya virus targeting non-structural protein 2 through molecular dynamics simulation

This study explores the potential of Indonesian herbal compounds against the chikungunya virus (CHIKV), which causes widespread illness without a specific cure known as chikungunya fever (CHIKF). By focusing on the nsP2 protein, crucial for the virus’s replication, the research utilizes computational methods identifying inhibitor compounds with high binding affinity. These promising candidates are further analyzed through 1 µs of molecular dynamic (MD) simulation studies, aiming to find effective inhibitors to control the chikungunya spread, leveraging Indonesia’s rich biodiversity for novel anti-CHIKV therapies. The results of our study highlight the molecular mechanism of the potential of epigallocatechin 3-O-gallate (EGCG) from Camelia sinensis in inhibiting nsP2 protease by binding to essential catalytic residues and exploring more energetically favorable orientations within the catalytic pocket. This dynamic binding process suggests that EGCG may disrupt the protease’s catalytic functions, potentially altering domain interactions without compromising the protein’s overall structure. Given nsP2’s minimal homology with human proteins, the risk of cross-reactivity is reduced, making it a suitable target for CHIKV therapy. This study suggests EGCG as a prime candidate for further development as a broad-spectrum inhibitor against CHIKF.

Magnetic field-assisted nanochain formation of intermixed catalytic Co-Pd nanoparticles.

Engineering on the nanoscale often involves optimizing performance by designing and creating new types of nanostructured materials. Multifunctional nanoparticles can be formed by combining elements that carry fundamentally different properties. The elements can be chosen based on the desired functionality, and by combining, e.g., magnetic, and catalytic elements, it is possible to self-assemble nanoparticles into catalytically active magnetic nanochains. However, mixing and assembling nanoparticles in a controlled way is challenging, and it is not obvious how the intermixing of the elements influences the properties of the individual nanoparticles. In this work, we synthesize and assemble intermixed magnetic and catalytic Cobalt-Palladium (Co-Pd) nanoparticles into multifunctional nanochains. The magnetic behavior is explored by studying the magnetic field-directed self-assembly of the nanoparticles into elongated nanochains. The catalytic properties are determined by measuring CO oxidation at elevated temperatures. Our results confirm that the magnetic and catalytic functionalities of the individual elements are retained when intermixed, which implies the potential to create nanochains with dual functionality that can be assembled in a controlled way.

Microcephaly, progressive, seizures, and cerebral and cerebellar atrophy: QARS1 variants associated with a severe phenotype in a patient

Microcephaly, progressive, seizures, and cerebral and cerebellar atrophy is a rare disease due to QARS1 pathogenic variants altering the Glutaminyl-tRNA synthetase 1 activity. We report a Tunisian child presenting with neonatal onset seizures, severe psychomotor delay, retinal abnormalities and MRI cerebral supratentorial atrophy lesions. Whole exome and Sanger sequencing revealed two compound heterozygous variants of QARS1. Three-dimensional analysis of the mutant Glutaminyl-tRNA synthetase 1 predicted altered catalytic and tRNA-binding functions. Genotype–phenotype correlations emphasize the combined effect of the zygosity and the location of the pathogenic variants within the protein domains on the severity of the disease.

Synchrotron-Based Characterizations of Electrocatalytic Metal-Organic Frameworks and Covalent Organic Framework-Based Solid Electrolyte Interphase for Stabilizing Anode of Rechargeable Batteries

Considering energy-related technologies including rechargeable batteries and water electrolysis, effective catalytic materials play a crucial role in the rise and unceasing development. Metal-organic frameworks (MOFs) have drawn attention due to their abundant and identical catalytic sites along the periodic network with tunable catalytic functionality and stability. Herein, structural information, catalytic sites, and their corresponding mechanistic pathways have been investigated by employing synchrotron-based X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). The framework stability, the accessible active sites related to pre-designed metal clusters, the alteration of oxidation state of, and the coordination geometry around the active metal centers evolving along the electrochemical oxygen evolution reaction (OER) are thoroughly revealed. In addition, aqueous zinc-ion batteries (AZIBs) are promising energy storage systems due to their cost-effectiveness and eco-friendliness. However, there are some limitations restricting their practical utilizations such as the high activity of water leading to Zn corrosion and hydrogen evolution, along with the formation of dendrites on the Zn surface during repeated charge–discharge cycles. To limit parasitic side reactions, an artificial solid electrolyte interphase (ASEI) protective layer made of a covalent organic framework (COFs) is an effective strategy. Herein, grazing-incidence XAS was employed to specifically characterize the Zn speciation on the electrode surface. According to XAS results, the protective COF-ASEI layer can retard the coordination of water at the electrolyte–Zn interface, improve Zn plating/stripping kinetics, and increase the stability of the Zn anode. This presentation highlights the significance of synchrotron characterizations in energy-related technologies.

Second-Sphere Histidine Catalytic Function in a Fungal Polysaccharide Monooxygenase.

Fungal polysaccharide monooxygenases (PMOs) oxidatively degrade cellulose and other carbohydrate polymers via a mononuclear copper active site using either O2 or H2O2 as a cosubstrate. Cellulose-active fungal PMOs in the auxiliary activity 9 (AA9) family have a conserved second-sphere hydrogen-bonding network consisting of histidine, glutamine, and tyrosine residues. The second-sphere histidine has been hypothesized to play a role in proton transfer in the O2-dependent PMO reaction. Here the role of the second-sphere histidine (H157) in an AA9 PMO, MtPMO9E, was investigated. This PMO is active on soluble cello-oligosaccharides such as cellohexaose (Glc6), thus enabling kinetic analysis with the point variants H157A and H157Q. The variants appeared to fold similarly to the wild-type (WT) enzyme and yet exhibited weaker affinity toward Glc6 than WT (WT KD = 20 ± 3 μM). The variants had comparable oxidase (O2 reduction to H2O2) activity to WT at all pH values tested. Using O2 as a cosubstrate, the variants were less active for Glc6 hydroxylation than WT, with H157A being the least active. Similarly, H157Q was competent for Glc6 hydroxylation with H2O2, but H157A was less active. Comparison of the crystal structures of H157Q and WT MtPMO9E reveals that a terminal heteroatom of Q157 overlays with Nε of H157. Altogether, the data suggest that H157 is not important for proton transfer, but support a role for H157 as a hydrogen-bond donor to diatomic-oxygen intermediates, thus facilitating catalysis with either O2 or H2O2.

UGT708S6 from Dendrobium catenatum, catalyzes the formation of flavonoid C-glycosides.

Dendrobium catenatum is a perennial herb of the genus Dendrobium orchidaceae. It has been known as "Golden Grass, Soft Gold" since ancient times with effects of strengthening the body, benefiting the stomach, generating body fluid, nourishing Yin and clearing internal heat. The flowers of D. catenatum have anti-oxidation, immune regulation and other biological activities. The composition analysis of flowers showed that flavonoid glycosides were significantly accumulated in floral tissue. However, in the flowers of D. catenatum, there was only one case of the UDP-glycosyltransferase (UGT) responsible for the glycosylation of flavonoids has been reported. In this study, a new UGT (named UGT708S6) was cloned from D. catenatum flowers rich in O-glycosides and C-glycosides, and its function and biochemical properties were characterized. Through homology comparison and molecular docking, we identified the key amino acid residues affecting the catalytic function of UGT708S6. The glycosyltransferase UGT708S6 was characterized and demonstrated C-glycosyltransferase (CGT) activity in vitro assay using phloretin and 2-hydroxynaringenin as sugar acceptors. The catalytic promiscuity assay revealed that UGT708S6 has a clear sugar donor preference, and displayed O-glycosyltransferase (OGT) activity towards luteolin, naringenin and liquiritigenin. Furthermore, the catalytic characteristics of UGT708S6 were explored, shedding light on the structural basis of substrate promiscuity and the catalytic mechanism involved in the formation of flavonoid C-glycosides. R271 was a key amino acid residue site that sustained the catalytic reaction. The smaller binding pocket resulted in the production of new O-glycosides and the reduction of C-glycosides. This highlighted the importance of the binding pocket in determining whether C-glycosides or O-glycosides were produced. The findings suggest that UGT708S6 holds promise as a new glycosyltransferase for synthesizing flavonoid glycosides and offer valuable insights for further understanding the catalytic mechanisms of flavonoid glycosyltransferases.

L-Histidine Modulates the Catalytic Activity and Conformational Changes of the HD3 Deoxyribozyme.

Background/Objectives: Riboswitches are functional nucleic acids that regulate biological processes by interacting with small molecules, such as metabolites, influencing gene expression. Artificial functional nucleic acids, including deoxyribozymes, have been developed through in vitro selection for various catalytic functions. In a previous study, an l-histidine-dependent deoxyribozyme was identified, exhibiting RNA cleavage activity in the presence of l-histidine resembling ribonuclease catalytic mechanisms. This study aims to clarify the role of l-histidine in the activity and structural formation of the l-histidine-dependent deoxyribozyme (HD), focusing on the binding properties and conformational changes of its derivative HD3. Methods: Conformational changes in HD3 were analyzed using circular dichroism (CD) under varying concentrations of l-histidine. Direct binding analysis was conducted using carbon-14 (14C)-labeled l-histidine and a liquid scintillation counter. The catalytic activity of HD3 in the presence of different l-histidine concentrations was measured. Results: The binding constant for l-histidine-induced conformational changes (Ka(CD)) was found to be 2.0 × 103 (M-1), whereas for catalytic activity (Ka(Rxn)) and scintillation counting (Ka(RI)), it was approximately 1.0 × 103 (M-1). Conclusions: l-Histidine plays an essential role in both the catalytic activity and structural formation of the HD3 deoxyribozyme. The consistent binding constants across different experimental methods highlight the significant contribution of l-histidine to the active folding of deoxyribozymes.

Microwave-assisted biodiesel synthesis from waste cooking oil: Exploring the potential of carob pod-derived solid base catalyst

This work examined the potency of carob (Ceratonia siliqua) pod as a heterogeneous base catalyst for converting waste cooking oil (WCO) into biodiesel via a microwave irradiation system. The optimal calcination for the catalyst synthesis was achieved at 500 °C for 4 h. Various analytical techniques were employed to investigate the properties of the developed catalyst. The results indicate that the catalyst primarily consists of mesoporous particles abundant in potassium, with medium to strong basic sites, which are crucial for its catalytic function. WCO underwent pretreatment with H2SO4 before being converted to biodiesel. Optimum conditions for the biodiesel production were a methanol-to-WCO molar ratio of 9.87, 1.00 wt% catalyst dosage, 3.03 min reaction time, 450 rpm stirring speed, and 600 W microwave power, yielding 98.20 ± 0.81 wt% biodiesel. The low specific energy consumption value of 0.91 kWh/kg and specific CO2 emission of 0.73 kg/kg of biodiesel suggest the effective utilization of microwave energy in driving the transesterification reaction and in promoting a reduction in carbon footprint, respectively. The synthesized catalyst remained effective up to the 5th production cycle and the biodiesel produced met established specifications. The results of this study show that carob pod is a suitable candidate to be included in the database of biobased catalysts currently being developed for heterogeneous catalysis of cost-effective biodiesel production.

Occurrence of protease-like catalytic activity in the polyclonal IgG in schizophrenia and bipolar disorder

Neuro-immune dysfunction and inflammation are said to be involved in the aetiology of major mental illnesses. This study describes the assessment of the protease-like catalytic function of serum IgG in psychiatric disorders, schizophrenia and bipolar disorder, along with healthy controls of Indian ethnicity. Systemic lupus erythematosus patients experiencing neuropsychiatry conditions were included as comparators for the comprehensive evaluation of IgG catalytic function. The catalytic activity of serum IgG was determined using the generic peptide substrate Pro-Phe-Arg-methylcoumarylamide, and then the apparent kinetic data was computed. Compared to healthy controls (n = 25), the activity of those with schizophrenia (n = 30) was found to be 11-fold higher. The neuropsychiatry lupus patients (n = 25) exhibited 2.7 times less activity than the schizophrenia group. The IgG activity of the bipolar patients’ (n = 30) were found to be 2.9 and 12 times higher than lupus and healthy controls. IgG activity showed a modest, no significant, link with PANSS positive and negative disease scores, in a subset of schizophrenia patients. The study’s findings express presence of catalytic antibodies in the blood as well as neuro-immune dysfunction in major psychosis disorders. In addition, subsets of schizophrenia patients indicate presence of autoimmune component in them.

Catalytic Enantioselective Functionalization of Maleimides: An Update

Comprehensive SummaryMaleimide derivatives are well‐established reactive intermediates also found in natural products, synthetic pharmaceuticals and functional polymers. Their specific reactivity found widespread applications in the field of bioconjugation and allowed for the development of highly selective functionalizations based on simple additions and cycloadditions with the possible control of central and C–N axial chirality. These multisite‐reactive scaffolds have aroused a long‐standing interest throughout the scientific community more particularly as powerful electrophilic partners and more recently as nucleophilic partners in some specific transformations. The persistent interest in these easily accessible synthetic platforms over the last decade has enabled the development of new enantioselective transformations and the major advancements in this field are presented in this review. Key Scientists

Computational Stabilization of a Non‐Heme Iron Enzyme Enables Efficient Evolution of New Function

AbstractDeep learning tools for enzyme design are rapidly emerging, and there is a critical need to evaluate their effectiveness in engineering workflows. Here we show that the deep learning‐based tool ProteinMPNN can be used to redesign Fe(II)/αKG superfamily enzymes for greater stability, solubility, and expression while retaining both native activity and industrially relevant non‐native functions. This superfamily has diverse catalytic functions and could provide a rich new source of biocatalysts for synthesis and industrial processes. Through systematic comparisons of directed evolution trajectories for a non‐native, remote C(sp3)−H hydroxylation reaction, we demonstrate that the stabilized redesign can be evolved more efficiently than the wild‐type enzyme. After three rounds of directed evolution, we obtained a 6‐fold activity increase from the wild‐type parent and an 80‐fold increase from the stabilized variant. To generate the initial stabilized variant, we identified multiple structural and sequence constraints to preserve catalytic function. We applied these criteria to produce stabilized, catalytically active variants of a second Fe(II)/αKG enzyme, suggesting that the approach is generalizable to additional members of the Fe(II)/αKG superfamily. ProteinMPNN is user‐friendly and widely accessible, and our results provide a framework for the routine implementation of deep learning‐based protein stabilization tools in directed evolution workflows for novel biocatalysts.