Light-Driven Metabolic Pathways in Non-Photosynthetic Biohybrid Bacteria.

Biomanufacturing via microorganisms relies on carbon substrates for molecular feedstocks and a source of energy to carry out enzymatic reactions. This creates metabolic bottlenecks and lowers the efficiency for substrate conversion. Nanoparticle biohybridization with proteins and whole cell surfaces can bypass the need for redox cofactor regeneration for improved secondary metabolite production in a non-specific manner. Here we propose using nanobiohybrid organisms (Nanorgs), intracellular protein-nanoparticle hybrids formed through the spontaneous coupling of core-shell quantum dots (QDs) with histidine-tagged enzymes in non-photosynthetic bacteria, for light-mediated control of bacterial metabolism. This proved to eliminate metabolic constrictions and replace glucose with light as the source of energy in Escherichia coli, with an increase in growth by 1.7-fold in 75 % reduced nutrient media. Metabolomic tracking through carbon isotope labeling confirmed flux shunting through targeted pathways, with accumulation of metabolites downstream of respective targets. Finally, application of Nanorgs with the Ehrlich pathway improved isobutanol titers/yield by 3.9-fold in 75 % less sugar from E. coli strains with no genetic alterations. These results demonstrate the promise of Nanorgs for metabolic engineering and low-cost biomanufacturing.

Transcriptome-based design of antisense inhibitors potentiates carbapenem efficacy in CRE Escherichia coli.

In recent years, the prevalence of carbapenem-resistant Enterobacteriaceae (CRE) has risen substantially, and the study of CRE resistance mechanisms has become increasingly important for antibiotic development. Although much research has focused on genomic resistance factors, relatively few studies have examined CRE pathogens through changes in gene expression. In this study, we examined the gene expression profile of a CRE Escherichia coli clinical isolate that is sensitive to meropenem but resistant to ertapenem to explore transcriptomic contributions to resistance and to identify gene knockdown targets for carbapenem potentiation. We sequenced total and short RNA to analyze the gene expression response to ertapenem or meropenem treatment and found significant expression changes in genes related to motility, maltodextrin metabolism, the formate hydrogenlyase complex, and the general stress response. To validate these findings, we used our laboratory's Facile Accelerated Specific Therapeutic (FAST) platform to create antisense peptide nucleic acids (PNAs), gene-specific molecules designed to inhibit protein translation. PNAs were designed to inhibit the pathways identified in our transcriptomic analysis, and each PNA was then tested in combination with each carbapenem to assess its effect on the antibiotics' minimum inhibitory concentrations. We observed significant PNA-antibiotic interaction with five different PNAs across six combinations. Inhibition of the genes hycA, dsrB, and bolA potentiated carbapenem efficacy in CRE E. coli, whereas inhibition of the genes flhC and ygaC conferred added resistance. Our results identify resistance factors and demonstrate that transcriptomic analysis is a potent tool for designing antibiotic PNA.

Design of a De Novo Aggregating Antimicrobial Peptide and a Bacterial Conjugation-Based Delivery System.

Antibacterial resistance necessitates the development of novel treatment methods for infections. Protein aggregates have recently been applied as antimicrobials to disrupt bacterial homeostasis. Past work on protein aggregates has focused on genome mining for aggregation-prone sequences in bacterial genomes rather than on rational design of aggregating antimicrobial peptides. Here, we use a synthetic biology approach to design an artificial gene encoding a de novo aggregating antimicrobial peptide. This artificial gene, opaL (overexpressed protein aggregator lipophilic), disrupts bacterial homeostasis by expressing extremely hydrophobic peptides. When this hydrophobic sequence is disrupted by acidic residues, consequent aggregation and antimicrobial effect decrease. Further, we developed a probiotic delivery system using the broad-host range conjugative plasmid RK2 to transfer the gene from donor to recipient bacteria. We utilize RK2 to mobilize a shuttle plasmid carrying opaL by adding the RK2 origin of transfer. We show that opaL is nontoxic to the donor, allowing for maintenance and transfer since its expression is under control of a promoter with a recipient-specific T7 RNA polymerase. Upon mating of donor and recipient Escherichia coli, we observe selective growth repression in T7 polymerase-expressing recipients. This technique could be used to target desired pathogens by selecting pathogen-specific promoters to control T7 RNA polymerase expression and provides a basis for the design and delivery of aggregating antimicrobial peptides.

Intracellular Hepatitis C Virus Modeling Predicts Infection Dynamics and Viral Protein Mechanisms.

Hepatitis C virus (HCV) infection is a global health problem, with nearly 2 million new infections occurring every year and up to 85% of these infections becoming chronic infections that pose serious long-term health risks. To effectively reduce the prevalence of HCV infection and associated diseases, it is important to understand the intracellular dynamics of the viral life cycle. Here, we present a detailed mathematical model that represents the full hepatitis C virus life cycle. It is the first full HCV model to be fit to acute intracellular infection data and the first to explore the functions of distinct viral proteins, probing multiple hypotheses of cis- and trans-acting mechanisms to provide insights for drug targeting. Model parameters were derived from the literature, experiments, and fitting to experimental intracellular viral RNA, extracellular viral titer, and HCV core and NS3 protein kinetic data from viral inoculation to steady state. Our model predicts higher rates for protein translation and polyprotein cleavage than previous replicon models and demonstrates that the processes of translation and synthesis of viral RNA have the most influence on the levels of the species we tracked in experiments. Overall, our experimental data and the resulting mathematical infection model reveal information about the regulation of core protein during infection, produce specific insights into the roles of the viral core, NS5A, and NS5B proteins, and demonstrate the sensitivities of viral proteins and RNA to distinct reactions within the life cycle.IMPORTANCE We have designed a model for the full life cycle of hepatitis C virus. Past efforts have largely focused on modeling hepatitis C virus replicon systems, in which transfected subgenomic HCV RNA maintains autonomous replication in the absence of virion production or spread. We started with the general structure of these previous replicon models and expanded it to create a model that incorporates the full virus life cycle as well as additional intracellular mechanistic detail. We compared several different hypotheses that have been proposed for different parts of the life cycle and applied the corresponding model variations to infection data to determine which hypotheses are most consistent with the empirical kinetic data. Because the infection data we have collected for this study are a more physiologically relevant representation of a viral life cycle than data obtained from a replicon system, our model can make more accurate predictions about clinical hepatitis C virus infections.

Near-Infrared-Light-Triggered Antimicrobial Indium Phosphide Quantum Dots.

The emergence of multidrug-resistant (MDR) pathogens represents one of the most urgent global public health crises. Light-activated quantum dots (QDs) are alternative antimicrobials, with efficient transport, low cost, and therapeutic efficacy, and they can act as antibiotic potentiators, with a mechanism of action orthogonal to small-molecule drugs. Furthermore, light-activation enhances control over the spatiotemporal release and dose of the therapeutic superoxide radicals from QDs. However, the limited deep-tissue penetration of visible light needed for QD activation, and concern over trace heavy metals, have prevented further translation. Herein, we report two indium phosphide (InP) QDs that operate in the near-infrared and deep-red light window, enabling deeper tissue penetration. These heavy-metal-free QDs eliminate MDR pathogenic bacteria, while remaining non-toxic to host human cells. This work provides a pathway for advancing QD nanotherapeutics to combat MDR superbugs.

High-Throughput Block Optical DNA Sequence Identification.

Optical techniques for molecular diagnostics or DNA sequencing generally rely on small molecule fluorescent labels, which utilize light with a wavelength of several hundred nanometers for detection. Developing a label-free optical DNA sequencing technique will require nanoscale focusing of light, a high-throughput and multiplexed identification method, and a data compression technique to rapidly identify sequences and analyze genomic heterogeneity for big datasets. Such a method should identify characteristic molecular vibrations using optical spectroscopy, especially in the "fingerprinting region" from ≈400-1400 cm-1 . Here, surface-enhanced Raman spectroscopy is used to demonstrate label-free identification of DNA nucleobases with multiplexed 3D plasmonic nanofocusing. While nanometer-scale mode volumes prevent identification of single nucleobases within a DNA sequence, the block optical technique can identify A, T, G, and C content in DNA k-mers. The content of each nucleotide in a DNA block can be a unique and high-throughput method for identifying sequences, genes, and other biomarkers as an alternative to single-letter sequencing. Additionally, coupling two complementary vibrational spectroscopy techniques (infrared and Raman) can improve block characterization. These results pave the way for developing a novel, high-throughput block optical sequencing method with lossy genomic data compression using k-mer identification from multiplexed optical data acquisition.

Conformational Smear Characterization and Binning of Single-Molecule Conductance Measurements for Enhanced Molecular Recognition.

Electronic conduction or charge transport through single molecules depends primarily on molecular structure and anchoring groups and forms the basis for a wide range of studies from molecular electronics to DNA sequencing. Several high-throughput nanoelectronic methods such as mechanical break junctions, nanopores, conductive atomic force microscopy, scanning tunneling break junctions, and static nanoscale electrodes are often used for measuring single-molecule conductance. In these measurements, "smearing" due to conformational changes and other entropic factors leads to large variances in the observed molecular conductance, especially in individual measurements. Here, we show a method for characterizing smear in single-molecule conductance measurements and demonstrate how binning measurements according to smear can significantly enhance the use of individual conductance measurements for molecular recognition. Using quantum point contact measurements on single nucleotides within DNA macromolecules, we demonstrate that the distance over which molecular junctions are maintained is a measure of smear, and the resulting variance in unbiased single measurements depends on this smear parameter. Our ability to identify individual DNA nucleotides at 20× coverage increases from 81.3% accuracy without smear analysis to 93.9% with smear characterization and binning (SCRIB). Furthermore, merely 7 conductance measurements (7× coverage) are needed to achieve 97.8% accuracy for DNA nucleotide recognition when only low molecular smear measurements are used, which represents a significant improvement over contemporary sequencing methods. These results have important implications in a broad range of molecular electronics applications from designing robust molecular switches to nanoelectronic DNA sequencing.

Single Nucleobase Identification Using Biophysical Signatures from Nanoelectronic Quantum Tunneling.

Nanoelectronic DNA sequencing can provide an important alternative to sequencing-by-synthesis by reducing sample preparation time, cost, and complexity as a high-throughput next-generation technique with accurate single-molecule identification. However, sample noise and signature overlap continue to prevent high-resolution and accurate sequencing results. Probing the molecular orbitals of chemically distinct DNA nucleobases offers a path for facile sequence identification, but molecular entropy (from nucleotide conformations) makes such identification difficult when relying only on the energies of lowest-unoccupied and highest-occupied molecular orbitals (LUMO and HOMO). Here, nine biophysical parameters are developed to better characterize molecular orbitals of individual nucleobases, intended for single-molecule DNA sequencing using quantum tunneling of charges. For this analysis, theoretical models for quantum tunneling are combined with transition voltage spectroscopy to obtain measurable parameters unique to the molecule within an electronic junction. Scanning tunneling spectroscopy is then used to measure these nine biophysical parameters for DNA nucleotides, and a modified machine learning algorithm identified nucleobases. The new parameters significantly improve base calling over merely using LUMO and HOMO frontier orbital energies. Furthermore, high accuracies for identifying DNA nucleobases were observed at different pH conditions. These results have significant implications for developing a robust and accurate high-throughput nanoelectronic DNA sequencing technique.

Photoexcited quantum dots for killing multidrug-resistant bacteria.

Multidrug-resistant bacterial infections are an ever-growing threat because of the shrinking arsenal of efficacious antibiotics. Metal nanoparticles can induce cell death, yet the toxicity effect is typically nonspecific. Here, we show that photoexcited quantum dots (QDs) can kill a wide range of multidrug-resistant bacterial clinical isolates, including methicillin-resistant Staphylococcus aureus, carbapenem-resistant Escherichia coli, and extended-spectrum ß-lactamase-producing Klebsiella pneumoniae and Salmonella typhimurium. The killing effect is independent of material and controlled by the redox potentials of the photogenerated charge carriers, which selectively alter the cellular redox state. We also show that the QDs can be tailored to kill 92% of bacterial cells in a monoculture, and in a co-culture of E. coli and HEK 293T cells, while leaving the mammalian cells intact, or to increase bacterial proliferation. Photoexcited QDs could be used in the study of the effect of redox states on living systems, and lead to clinical phototherapy for the treatment of infections.

ROS mediated selection for increased NADPH availability in Escherichia coli.

The economical production of chemicals and fuels by microbial processes remains an intense area of interest in biotechnology. A key limitation in such efforts concerns the availability of key co-factors, in this case NADPH, required for target pathways. Many of the strategies pursued for increasing NADPH availability in Escherichia coli involve manipulations to the central metabolism, which can create redox imbalances and overall growth defects. In this study we used a reactive oxygen species based selection to search for novel methods of increasing NADPH availability. We report a loss of function mutation in the gene hdfR appears to increase NADPH availability in E. coli. Additionally, we show this excess NADPH can be used to improve the production of 3HP in E. coli.

Antagonistic self-sensing and mate-sensing signaling controls antibiotic-resistance transfer.

Conjugation is one of the most common ways bacteria acquire antibiotic resistance, contributing to the emergence of multidrug-resistant "superbugs." Bacteria of the genus Enterococcus faecalis are highly antibiotic-resistant nosocomial pathogens that use the mechanism of conjugation to spread antibiotic resistance between resistance-bearing donor cells and resistance-deficient recipient cells. Here, we report a unique quorum sensing-based communication system that uses two antagonistic signaling molecules to regulate conjugative transfer of tetracycline-resistance plasmid pCF10 in E. faecalis. A "mate-sensing" peptide sex pheromone produced by recipient cells is detected by donor cells to induce conjugative genetic transfer. Using mathematical modeling and experimentation, we show that a second antagonistic "self-sensing" signaling peptide, previously known to suppress self-induction of donor cells, also serves as a classic quorum-sensing signal for donors that functions to reduce antibiotic-resistance transfer at high donor density. This unique form of quorum sensing may provide a means of limiting the spread of the plasmid and present opportunities to control antibiotic-resistance transfer through manipulation of intercellular signaling, with implications in the clinical setting.

Convergent transcription confers a bistable switch in Enterococcus faecalis conjugation.

Convergent gene pairs with head-to-head configurations are widespread in both eukaryotic and prokaryotic genomes and are speculated to be involved in gene regulation. Here we present a unique mechanism of gene regulation due to convergent transcription from the antagonistic prgX/prgQ operon in Enterococcus faecalis controlling conjugative transfer of the antibiotic resistance plasmid pCF10 from donor cells to recipient cells. Using mathematical modeling and experimentation, we demonstrate that convergent transcription in the prgX/prgQ operon endows the system with the properties of a robust genetic switch through premature termination of elongating transcripts due to collisions between RNA polymerases (RNAPs) transcribing from opposite directions and antisense regulation between complementary counter-transcripts. Evidence is provided for the presence of truncated RNAs resulting from convergent transcription from both the promoters that are capable of sense-antisense interactions. A mathematical model predicts that both RNAP collision and antisense regulation are essential for a robust bistable switch behavior in the control of conjugation initiation by prgX/prgQ operons. Moreover, given that convergent transcription is conserved across species, the mechanism of coupling RNAP collision and antisense interaction is likely to have a significant regulatory role in gene expression.

Cell-Penetrating Peptide Delivery of Nucleic Acid Cargo to Emiliania huxleyi, a Calcifying Marine Coccolithophore.

Coccolithophores are a group of unicellular marine phytoplankton that exhibit a prolific capacity for carbon conversion and are critical to ocean biogeochemistry. A fundamental understanding of coccolithophore biomineralization has been limited, in part, by the lack of genetic and molecular tools to investigate the organisms. In particular, it has proven to be difficult to deliver macromolecules across the coccosphere-membrane complex. To overcome this barrier, we employed cell-penetrating peptides (CPP) in the Emiliania huxleyi coccolithophores. We evaluated three established CPPs (TAT, R9, and KFF) and designed a CPP that incorporates a high proline content identified in the protein transduction domain of EhV060, an E. huxleyi virus lectin protein. To measure the delivery performance, we covalently linked CPPs to synthetic peptide nucleic acids (PNA) and attached a fluorescein marker. CPP-PNA-FITC complexes were efficiently delivered across the coccosphere-membrane complex to the cytoplasm of E. huxleyi cells. Characterization of E. huxleyi demonstrates that CPP-PNA are nontoxic and reveals specific effects of CPP-PNA on cell biology and calcification. Direct delivery and characterization of synthetic nucleic acids represent a step forward in synthetic biology to explore coccolithophore biomineralization.

A systematic review of peptide nucleic acids (PNAs) with antibacterial activities: Efficacy, potential and challenges.

Peptide nucleic acids (PNAs) are synthetic molecules that are like DNA/RNA, but with different building blocks. PNAs target and bind to mRNAs and disrupt the function of a targeted gene, hence they have been studied as potential antibacterials. The aim of this systematic review was to provide an in-depth analysis of the current status of PNAs as antibacterial agents, define the characteristics of the effective PNA constructs, and address the gap in advancing PNAs to become clinically competent agents. Following the PRISMA model, four electronic databases were searched: Web of Science, PubMed, SciFinder and Scopus. A total of 627 articles published between 1994 and 2023 were found. After screening and a rigorous selection process using explicit inclusion and exclusion criteria, 65 scientific articles were selected, containing 656 minimum inhibitory concentration (MIC) data. The antibacterial activity of PNAs was assessed against 20 bacterial species. The most studied Gram-negative and Gram-positive bacteria were Escherichia coli (n=266) and Staphylococcus aureus (n=53), respectively. In addition, the effect of PNA design, including construct length, binding location, and carrier agents, on antibacterial activity was shown. Finally, antibacterial test models to assess the inhibitory effects of PNAs were examined, emphasising gaps and prospects. This systematic review provides a comprehensive assessment of the potential of PNAs as antibacterial agents and offers valuable insights for researchers and clinicians seeking novel therapeutic strategies in the context of increasing rates of antibiotic-resistant bacteria.

Targeted-Neuroinflammation Mitigation Using Inflammasome-Inhibiting Nanoligomers is Therapeutic in an Experimental Autoimmune Encephalomyelitis Mouse Model.

Multiple sclerosis (MS) is a debilitating autoimmune disease that impacts millions of patients worldwide, disproportionately impacting women (4:1), and often presenting at highly productive stages of life. This disease affects the spinal cord and brain and is characterized by severe neuroinflammation, demyelination, and subsequent neuronal damage, resulting in symptoms like loss of mobility. While untargeted and pan-immunosuppressive therapies have proven to be disease-modifying and manage (or prolong the time between) symptoms in many patients, a significant fraction are unable to achieve remission. Recent work has suggested that targeted neuroinflammation mitigation through selective inflammasome inhibition can offer relief to patients while preserving key components of immune function. Here, we show a screening of potential therapeutic targets using inflammasome-inhibiting Nanoligomers (NF-κB1, TNFR1, TNF-α, IL-6) that meet or far-exceed commercially available small-molecule counterparts like ruxolitinib, MCC950, and deucravacitinib. Using the human brain organoid model, top Nanoligomer combinations (NF-κB1 + TNFR1: NI111, and NF-κB1 + NLRP3: NI112) were shown to significantly reduce neuroinflammation without any observable negative impact on organoid function. Further testing of these top Nanoligomer combinations in an aggressive experimental autoimmune encephalomyelitis (EAE) mouse model for MS using intraperitoneal (IP) injections showed that NF-κB1 and NLRP3 targeting Nanoligomer combination NI112 rescues mice without observable loss of mobility or disability, minimal inflammation in brain and spinal cord histology, and minimal to no immune cell infiltration of the spinal cord and no demyelination, similar to or at par with mice that received no EAE injections (negative control). Mice receiving NI111 (NF-κB1 + TNFR1) also showed reduced neuroinflammation compared to saline (sham)-treated EAE mice and at par/similar to other inflammasome-inhibiting small molecule treatments, although it was significantly higher than NI112 leading to subsequent worsening clinical outcomes. Furthermore, treatment with an oral formulation of NI112 at lower doses showed a significant reduction in EAE severity, albeit with higher variance owing to administration and formulation/fill-and-finish variability. Overall, these results point to the potential of further development and testing of these inflammasome-targeting Nanoliogmers as an effective neuroinflammation treatment for multiple neurodegenerative diseases and potentially benefit several patients suffering from such debilitating autoimmune diseases like MS.

Nanoligomers targeting NF-κB and NLRP3 reduce neuroinflammation and improve cognitive function with aging and tauopathy.

Neuroinflammation contributes to impaired cognitive function in brain aging and neurodegenerative disorders like Alzheimer's disease, which is characterized by the aggregation of pathological tau. One major driver of both age- and tau-associated neuroinflammation is the NF-κB and NLRP3 signaling axis. However, current treatments targeting NF-κB or NLRP3 may have adverse/systemic effects, and most have not been clinically translatable. In this study, we tested the efficacy of a novel, nucleic acid therapeutic (Nanoligomer) cocktail specifically targeting both NF-κB and NLRP3 in the brain for reducing neuroinflammation and improving cognitive function in old (aged 19 months) wildtype mice, and in rTg4510 tau pathology mice (aged 2 months). We found that 4 weeks of NF-κB/NLRP3-targeting Nanoligomer treatment strongly reduced neuro-inflammatory cytokine profiles in the brain and improved cognitive-behavioral function in both old and rTg4510 mice. These effects of NF-κB/NLRP3-targeting Nanoligomers were also associated with reduced glial cell activation and pathology, favorable changes in transcriptome signatures of glia-associated inflammation (reduced) and neuronal health (increased), and positive systemic effects. Collectively, our results provide a basis for future translational studies targeting both NF-κB and NLRP3 in the brain, perhaps using Nanoligomers, to inhibit neuroinflammation and improve cognitive function with aging and neurodegeneration.

NF-κB/NLRP3 Translational Inhibition by Nanoligomer Therapy Mitigates Ethanol and Advanced Age-Related Neuroinflammation.

Binge alcohol use is increasing among aged adults (>65 years). Alcohol-related toxicity in aged adults is associated with neurodegeneration, yet the molecular underpinnings of age-related sensitivity to alcohol are not well described. Studies utilizing rodent models of neurodegenerative disease reveal heightened activation of Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and Nod like receptor 3 (NLRP3) mediate microglia activation and associated neuronal injury. Our group, and others, have implicated hippocampal-resident microglia as key producers of inflammatory mediators, yet the link between inflammation and neurodegeneration has not been established in models of binge ethanol exposure and advanced age. Here, we report binge ethanol increased the proportion of NLRP3+ microglia in the hippocampus of aged (18-20 months) female C57BL/6N mice compared to young (3-4 months). In primary microglia, ethanol-induced expression of reactivity markers and NLRP3 inflammasome activation were more pronounced in microglia from aged mice compared to young. Making use of an NLRP3-specific inhibitor (OLT1177) and a novel brain-penetrant Nanoligomer that inhibits NF-κB and NLRP3 translation (SB_NI_112), we find ethanol-induced microglial reactivity can be attenuated by OLT1177 and SB_NI_112 in microglia from aged mice. In a model of intermittent binge ethanol exposure, SB_NI_112 prevented ethanol-mediated microglia reactivity, IL-1ß production, and tau hyperphosphorylation in the hippocampus of aged mice. These data suggest early indicators of neurodegeneration occurring with advanced age and binge ethanol exposure are NF-κB- and NLRP3-dependent. Further investigation is warranted to explore the use of targeted immunosuppression via Nanoligomers to attenuate neuroinflammation after alcohol consumption in the aged.

Targeting Neuroinflammation by Pharmacologic Downregulation of Inflammatory Pathways Is Neuroprotective in Protein Misfolding Disorders.

Neuroinflammation plays a crucial role in the development of neurodegenerative protein misfolding disorders. This category of progressive diseases includes, but is not limited to, Alzheimer's disease, Parkinson's disease, and prion diseases. Shared pathogenesis involves the accumulation of misfolded proteins, chronic neuroinflammation, and synaptic dysfunction, ultimately leading to irreversible neuronal loss, measurable cognitive deficits, and death. Presently, there are few to no effective treatments to halt the advancement of neurodegenerative diseases. We hypothesized that directly targeting neuroinflammation by downregulating the transcription factor, NF-κB, and the inflammasome protein, NLRP3, would be neuroprotective. To achieve this, we used a cocktail of RNA targeting therapeutics (SB_NI_112) shown to be brain-penetrant, nontoxic, and effective inhibitors of both NF-κB and NLRP3. We utilized a mouse-adapted prion strain as a model for neurodegenerative diseases to assess the aggregation of misfolded proteins, glial inflammation, neuronal loss, cognitive deficits, and lifespan. Prion-diseased mice were treated either intraperitoneally or intranasally with SB_NI_112. Behavioral and cognitive deficits were significantly protected by this combination of NF-κB and NLRP3 downregulators. Treatment reduced glial inflammation, protected against neuronal loss, prevented spongiotic change, rescued cognitive deficits, and significantly lengthened the lifespan of prion-diseased mice. We have identified a nontoxic, systemic pharmacologic that downregulates NF-κB and NLRP3, prevents neuronal death, and slows the progression of neurodegenerative diseases. Though mouse models do not always predict human patient success and the study was limited due to sample size and number of dosing methods utilized, these findings serve as a proof of principle for continued translation of the therapeutic SB_NI_112 for prion disease and other neurodegenerative diseases. Based on the success in a murine prion model, we will continue testing SB_NI_112 in a variety of neurodegenerative disease models, including Alzheimer's disease and Parkinson's disease.

Light-driven Transformation of Carbon Monoxide into Hydrocarbons using CdS@ZnS : VFe Protein Biohybrids.

Enzymatic Fisher-Tropsch (FT) process catalyzed by vanadium (V)-nitrogenase can convert carbon monoxide (CO) to longer-chain hydrocarbons (>C2) under ambient conditions, although this process requires high-cost reducing agent(s) and/or the ATP-dependent reductase as electron and energy sources. Using visible light-activated CdS@ZnS (CZS) core-shell quantum dots (QDs) as alternative reducing equivalent for the catalytic component (VFe protein) of V-nitrogenase, we first report a CZS : VFe biohybrid system that enables effective photo-enzymatic C-C coupling reactions, hydrogenating CO into hydrocarbon fuels (up to C4) that can be hardly achieved with conventional inorganic photocatalysts. Surface ligand engineering optimizes molecular and opto-electronic coupling between QDs and the VFe protein, realizing high efficiency (internal quantum yield >56 %), ATP-independent, photon-to-fuel production, achieving an electron turnover number of >900, that is 72 % compared to the natural ATP-coupled transformation of CO into hydrocarbons by V-nitrogenase. The selectivity of products can be controlled by irradiation conditions, with higher photon flux favoring (longer-chain) hydrocarbon generation. The CZS : VFe biohybrids not only can find applications in industrial CO removal for high-value-added chemical production by using the cheap, renewable solar energy, but also will inspire related research interests in understanding the molecular and electronic processes in photo-biocatalytic systems.