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During the COVID-19 2020 outbreak, a large body of data has been provided on general management and outcomes of hospitalized COVID-19 patients. Yet, relatively little is known on characteristics and outcome of patients managedin Internal Medicine Units (IMU). To address this gap, the Italian Society of Internal Medicine has conducted a nationwide cohort multicentre study on death outcome in adult COVID-19 patients admitted and managed in IMU. This study assessed 3044 COVID-19 patients at 41 referral hospitals across Italy from February 3rd to May 8th 2020. Demographics, comorbidities, organ dysfunction, treatment, and outcomes including death were assessed. During the study period, 697 patients (22.9%) were transferred to intensive care units, and 351 died in IMU (death rate 14.9%). At admission, factors independently associated with in-hospital mortality were age (OR 2.46, p = 0.000), productive cough (OR 2.04, p = 0.000), pre-existing chronic heart failure (OR 1.58, p = 0.017) and chronic obstructive pulmonary disease (OR 1.17, p = 0.048), the number of comorbidities (OR 1.34, p = 0.000) and polypharmacy (OR 1.20, p = 0.000). Of note, up to 40% of elderly patients did not report fever at admission. Decreasing PaO2/FiO2 ratio at admission was strongly inversely associated with survival. The use of conventional oxygen supplementation increased with the number of pre-existing comorbidities, but it did not associate with better survival in patients with PaO2/FiO2 ratio

Pollution, accidents, and misinformation have earned the pharmaceutical and chemical industry a poor public reputation, despite their undisputable importance to society. Biotechnological advances hold the promise to enable a future of drastically reduced environmental impact and rigorously more efficient production routes at the same time. This is exemplified in the Baeyer-Villiger reaction, which offers a simple synthetic route to oxidize ketones to esters, but application is hampered by the requirement of hazardous and dangerous reagents. As an attractive alternative, flavin-containing Baeyer-Villiger monooxygenases (BVMOs) have been investigated for their potential as biocatalysts for a long time, and many variants have been characterized. After a general look at the state of biotechnology, we here summarize the literature on biochemical characterizations, mechanistic and structural investigations, as well as enzyme engineering efforts in BVMOs. With a focus on recent developments, we critically outline the advances toward tuning these enzymes suitable for industrial applications.

With the aim of applying redox-neutral cascade reactions in organic media, fusions of a type II flavin-containing monooxygenase (FMO-E) and horse liver alcohol dehydrogenase (HLADH) were designed. The enzyme orientation and expression vector were found to influence the overall fusion enzyme activity. The resulting bifunctional enzyme retained the catalytic properties of both individual enzymes. The lyophilized cell-free extract containing the bifunctional enzyme was applied for the convergent cascade reaction consisting of cyclobutanone and butane-1,4-diol in different microaqueous media with only 5 % (v/v) aqueous buffer without any addition of external cofactor. Methyl tert-butyl ether and cyclopentyl methyl ether were found to be the best organic media for the synthesis of γ-butyrolactone, resulting in about 27 % analytical yield.

BACKGROUND. Patients with coronavirus disease 2019 (COVID-19) develop pneumonia generally associated with lymphopenia and a severe inflammatory response due to uncontrolled cytokine release. These mediators are transcriptionally regulated by the JAK/ STAT signaling pathways, which can be disabled by small molecules. METHODS. We treated a group of patients (n = 20) with baricitinib according to an off-label use of the drug. The study was designed as an observational, longitudinal trial and approved by the local ethics committee. The patients were treated with 4 mg baricitinib twice daily for 2 days, followed by 4 mg per day for the remaining 7 days. Changes in the immune phenotype and expression of phosphorylated STAT3 (p-STAT3) in blood cells were evaluated and correlated with serum-derived cytokine levels and antibodies against severe acute respiratory syndrome–coronavirus 2 (anti–SARS-CoV-2). In a single treated patient, we also evaluated the alteration of myeloid cell functional activity. RESULTS. We provide evidence that patients treated with baricitinib had a marked reduction in serum levels of IL-6, IL-1β, and TNF-α, a rapid recovery of circulating T and B cell frequencies, and increased antibody production against the SARS-CoV-2 spike protein, all of which were clinically associated with a reduction in the need for oxygen therapy and a progressive increase in the P/F (PaO2, oxygen partial pressure/FiO2, fraction of inspired oxygen) ratio. CONCLUSION. These data suggest that baricitinib prevented the progression to a severe, extreme form of the viral disease by modulating the patients’ immune landscape and that these changes were associated with a safer, more favorable clinical outcome for patients with COVID-19 pneumonia.

Enzyme instability is an important limitation for the investigation and application of enzymes. Therefore, methods to rapidly and effectively improve enzyme stability are highly appealing. In this study we applied a computational method (FRESCO) to guide the engineering of an alcohol dehydrogenase. Of the 177 selected mutations, 25 mutations brought about a significant increase in apparent melting temperature (Delta T-m >= +3 degrees C). By combining mutations, a 10-fold mutant was generated with a T-m of 94 degrees C (+51 degrees C relative to wild type), almost reaching water's boiling point, and the highest increase with FRESCO to date. The 10-fold mutant's structure was elucidated, which enabled the identification of an activity-impairing mutation. After reverting this mutation, the enzyme showed no loss in activity compared to wild type, while displaying a T-m of 88 degrees C (+45 degrees C relative to wild type). This work demonstrates the value of enzyme stabilization through computational library design.

To expand the arsenal of industrially applicable oxidative enzymes, fusions of alcohol dehydrogenases with an NADPH‐oxidase were designed. Three different alcohol dehydrogenases (LbADH, TbADH, ADHA) were expressed with a thermostable NADPH‐oxidase fusion partner (PAMO C65D) and purified. The resulting bifunctional biocatalysts retained the catalytic properties of the individual enzymes, and acted essentially like alcohol oxidases: transforming alcohols to ketones by using dioxygen as mild oxidant, while merely requiring a catalytic amount of NADP+. In small‐scale reactions, the purified fusion enzymes show good performances, with 69–99 % conversion, 99 % ee with a racemic substrate, and high cofactor and enzyme total turnover numbers. As the fusion enzymes essentially act as oxidases, we found that commonly used high‐throughput oxidase‐activity screening methods can be used. Therefore, if needed, the fusion enzymes could be easily engineered to tune their properties., Going self‐sufficient: Alcohol dehydrogenases (ADHs) can catalyze selective alcohol oxidations and can be applied to kinetically resolve racemic alcohols, or to produce carbonyl building blocks. By fusing ADHs with an NADPH oxidase, self‐sufficient biocatalysts can be produced that act like alcohol oxidases. These enzyme fusions can be used for conversions and for activity screening to aid enzyme engineering.

Enzymes are the core of biological life. These tiny molecular machines can transform molecules, which enables organisms to grow. Aside from their biological role, enzymes are also used for various applications, such as: brewing of beer, making cheese, and removing dirt from clothes.There is great interest in the application of enzymes for the production of useful compounds, such as: (bio)materials, (bio)fuels, medicine, and food additives. Compared to chemical processes, a process with enzymes is greener and more sustainable. However, enzymes from nature are often not stable enough for large-scale industrial application; they rapidly fall apart. Aside from this lack of stability, it is also difficult and costly to produce enzymes.In this thesis, we studied the approach of producing two enzymes together, as one: enzyme fusion. Not only does this make the production of enzymes more favorable, in some cases the enzymes can directly work together in a 2-step process.In the final research chapter, we used another approach to improve enzyme application: mutagenesis through computational predictions. Enzymes are composed of hundreds of amino acids, and single amino acids can be exchanged by mutagenesis. Each amino acid interacts with all neighbouring amino acids. By swapping an amino acid with another one of different shape and property, such that it can make more and better interactions with the neighbouring amino acids, we can fortify the enzyme’s structure. The mutated enzyme could nearly resist boiling water, while the original enzyme fell apart around 40 °C.

NADPH-oxidases (NOXs) purposefully produce reactive-oxygen-species (ROS) and are found in most kingdoms of life. The seven human NOXs are each characterized by a specific expression profile and a fine regulation to spatio-temporally tune ROS concentration in cells and tissues. One of the best known roles for NOXs is in host protection against pathogens but ROS themselves are important second messengers involved in tissue regeneration and the modulation of pathways that induce and sustain cell proliferation. As such, NOXs are attractive pharmacological targets in immunomodulation, fibrosis and cancer. We have studied an extensive number of available NOX inhibitors, with the specific aim to identify bona fide ligands versus ROS-scavenging molecules. Accordingly, we have established a comprehensive platform of biochemical and biophysical assays. Most of the investigated small molecules revealed ROS-scavenging and/or assay-interfering properties to various degrees. A few compounds, however, were also demonstrated to directly engage one or more NOX enzymes. Diphenylene iodonium was found to react with the NOXs’ flavin and heme prosthetic groups to form stable adducts. We also discovered that two compounds, VAS2870 and VAS3947, inhibit NOXs through the covalent alkylation of a cysteine residue. Importantly, the amino acid involved in covalent binding was found to reside in the dehydrogenase domain, where the nicotinamide ring of NADPH is bound. This work can serve as a springboard to guide further development of bona fide ligands with either agonistic or antagonistic properties toward NOXs., Graphical abstract Image 1, Highlights • NOX inhibition by twenty-four compounds was tested using multiple assays. • Most of the evaluated compounds displayed significant ROS scavenging and/or assay-interfering effects. • DPI is demonstrated to engage the heme and the flavin cofactors of NOXs. • VAS2870 and VAS3947 are covalent bona-fide NOX inhibitors. • A conserved active-site cysteine can be targeted for inhibition.

In this manuscript we describe how, by taking a systems approach, complex energy landscapes of supramolecular assemblies can be navigated using stoichiometry to control, with remarkable selectivity, which assembly gets populated. The perhaps counterintuitive finding is that it is not necessarily the assembly that, in a one-to-one comparison, is the most stable that wins the competition for common building blocks, even though the system is under thermodynamic control. Instead, an individually less stable assembly may completely dominate the system. This domination is possible when the building block stoichiometry in the system matches the stoichiometry of this specific assembly, allowing the system to maximize binding energy by making a large number of assemblies of moderate stability as opposed to a small number of more stable assemblies.

One approach to bringing enzymes together for multienzyme biocatalysis is genetic fusion. This enables the production of multifunctional enzymes that can be used for whole‐cell biotransformations or for in vitro (cascade) reactions. In some cases and in some aspects, such as expression and conversions, the fused enzymes outperform a combination of the individual enzymes. In contrast, some enzyme fusions are greatly compromised in activity and/or expression. In this Minireview, we give an overview of studies on fusions between two or more enzymes that were used for biocatalytic applications, with a focus on oxidative enzymes. Typically, the enzymes are paired to facilitate cofactor recycling or cosubstrate supply. In addition, different linker designs are briefly discussed. Although enzyme fusion is a promising tool for some biocatalytic applications, future studies could benefit from integrating the findings of previous studies in order to improve reliability and effectiveness.

Glycoside hydrolases are clustered into families based on amino acid sequence similarities, and belonging to a particular family can infer biological activity of an enzyme. Family GH115 contains α-glucuronidases where several members have been shown to hydrolyze terminal α-1,2-linked glucuronic acid and 4-O-methylated glucuronic acid from the plant cell wall polysaccharide glucuronoxylan. Other GH115 enzymes show no activity on glucuronoxylan, and therefore, it has been proposed that family GH115 may be a poly-specific family. In this study, we reveal that a putative periplasmic GH115 from the human gut symbiont Bacteroides thetaiotaomicron, BtGH115A, hydrolyzes terminal 4-O-methyl-glucuronic acid residues from decorated arabinogalactan isolated from acacia tree. The three-dimensional structure of BtGH115A reveals that BtGH115A has the same domain architecture as the other structurally characterized member of this family, BoAgu115A; however the position of the C-terminal module is altered with respect to each individual enzyme. Phylogenetic analysis of GH115 amino sequences divides the family into distinct clades that may distinguish different substrate specificities. Finally, we show that BtGH115A α-glucuronidase activity is necessary for the sequential digestion of branched galactans from acacia gum by a galactan-β-1,3-galactosidase from family GH43; however, while B. thetaiotaomicron grows on larch wood arabinogalactan, the bacterium is not able to metabolize acacia gum arabinogalactan, suggesting that BtGH115A is involved in degradation of arabinogalactan fragments liberated by other microbial species in the gastrointestinal tract.

The monomers 2-methyl-2-oxazine (MeOZI), 2-ethyl-2-oxazine (EtOZI), and 2-n-propyl-2-oxazine (nPropOZI) were synthesized and polymerized via the living cationic ring-opening polymerization (CROP) under microwave-assisted conditions. pEtOZI and pnPropOZI were found to be thermoresponsive, exhibiting LCST behavior in water and their cloud point temperatures (T(CP)) are lower than for poly(2-oxazoline)s with similar side chains. However, comparison of poly(2-oxazine) and poly(2-oxazoline)s isomers reveals that poly(2-oxazine)s are more water soluble, indicating that the side chain has a stronger impact on polymer solubility than the main chain. In conclusion, variations of both the side chains and the main chains of the poly(cyclic imino ether)s resulted in a series of distinct homopolymers with tunable T(CP).