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INTRODUCTION: COVID-19 causes a considerable degradation of pulmonary function to the point of an acute respiratory distress syndrome (ARDS). Over the course of the disease the gas exchange capability of the lung can get impaired to such an extent that extracorporeal membrane oxygenation (ECMO) is needed as a life-saving intervention. In patients COVID-19 as well as ECMO may cause severe coagulopathies which manifest themselves in micro and macro thrombosis. Previous studies established D-dimers as a marker for critical thrombosis of the ECMO system while on admission increased D-dimers are associated with a higher mortality in COIVD-19 patients. It is therefore crucial to determine if COVID-19 poses an increased risk of early thrombosis of the vital ECMO system. METHODS: 40 patients who required ECMO support were enrolled in a retrospective analysis and assigned into 2 groups. The COVID group consist of 20 COVID-19 patients who required ECMO support (n = 20), whereas 20 ECMO patients without COVID-19 were assigned to the control group. D-dimers, fibrinogen, antithrombin III (AT III), lactate dehydrogenase (LDH) and platelet count were analysed using locally weighted scatterplot smoothing and MANOVAs. RESULTS: The analysis of both groups shows highly significant differences in the dynamics of hemostasis. The increase in D-dimers that is associated with thrombosis of the ECMO systems occurs in COVID-19 patients around 2 days earlier (p = 2,8115 10–11) while fibrinogen is consumed steadily. In the control group fibrinogen levels increase rapidly after ten days with a plateau phase of around five days (p = 1,407 10–3) . Both groups experience a rapid increase in AT III after start of support by ECMO (p = 5,96 10–15). In the COVID group platelet count decreased from 210 giga/l to 130 giga/l within eight days, while in the same time span in the control group platelets decreased from 180 giga/l to 105 giga/l (p = 1,1 10–15). In both groups a marked increase in LDH beyond 5000 U/l occurs (p = 3,0865 10–15). CONCLUSION: The early increase in D-dimers and decrease in fibrinogen suggests that COVID-19 patients bear an increased risk of early thrombosis of the ECMO system compared to other diseases treated with ECMO. Additionally, the control group shows signs of severe inflammation 10 days after the start of ECMO which were absent in COVID-19 patients. [ABSTRACT FROM AUTHOR]

INTRODUCTION: COVID-19 causes a considerable degradation of pulmonary function to the point of an acute respiratory distress syndrome (ARDS). Over the course of the disease the gas exchange capability of the lung can get impaired to such an extent that extracorporeal membrane oxygenation (ECMO) is needed as a life-saving intervention. In patients COVID-19 as well as ECMO may cause severe coagulopathies which manifest themselves in micro and macro thrombosis. Previous studies established D-dimers as a marker for critical thrombosis of the ECMO system while on admission increased D-dimers are associated with a higher mortality in COIVD-19 patients. It is therefore crucial to determine if COVID-19 poses an increased risk of early thrombosis of the vital ECMO system. METHODS: 40 patients who required ECMO support were enrolled in a retrospective analysis and assigned into 2 groups. The COVID group consist of 20 COVID-19 patients who required ECMO support (n = 20), whereas 20 ECMO patients without COVID-19 were assigned to the control group. D-dimers, fibrinogen, antithrombin III (AT III), lactate dehydrogenase (LDH) and platelet count were analysed using locally weighted scatterplot smoothing and MANOVAs. RESULTS: The analysis of both groups shows highly significant differences in the dynamics of hemostasis. The increase in D-dimers that is associated with thrombosis of the ECMO systems occurs in COVID-19 patients around 2 days earlier (p = 2,8115 10–11) while fibrinogen is consumed steadily. In the control group fibrinogen levels increase rapidly after ten days with a plateau phase of around five days (p = 1,407 10–3) . Both groups experience a rapid increase in AT III after start of support by ECMO (p = 5,96 10–15). In the COVID group platelet count decreased from 210 giga/l to 130 giga/l within eight days, while in the same time span in the control group platelets decreased from 180 giga/l to 105 giga/l (p = 1,1 10–15). In both groups a marked increase in LDH beyond 5000 U/l occurs (p = 3,0865 10–15). CONCLUSION: The early increase in D-dimers and decrease in fibrinogen suggests that COVID-19 patients bear an increased risk of early thrombosis of the ECMO system compared to other diseases treated with ECMO. Additionally, the control group shows signs of severe inflammation 10 days after the start of ECMO which were absent in COVID-19 patients. [ABSTRACT FROM AUTHOR]

Online analytics provides insights into the progress of an ongoing reaction without the need for extensive sampling and offline analysis. In this study, we investigated benchtop NMR as an online reaction monitoring tool for complex enzyme cascade reactions. Online NMR was used to monitor a two‐step cascade beginning with an aromatic aldehyde and leading to an aromatic amino alcohol as the final product, applying two different enzymes and a variety of co‐substrates and intermediates. Benchtop NMR enabled the concentration of the reaction components to be detected in buffered systems in the single‐digit mM range without using deuterated solvent. The concentrations determined via NMR were correlated with offline samples analyzed via uHPLC and displayed a good correlation between the two methods. In summary, benchtop NMR proved to be a sensitive, selective and reliable method for online reaction monitoring in (multi‐step) biosynthesis. In future, online analytic systems such as the benchtop NMR devices described might not only enable direct monitoring of the reaction, but may also form the basis for self‐regulation in biocatalytic reactions. [ABSTRACT FROM AUTHOR]

Compartmentalization of biocatalysts is an effective tool to integrate biocatalytic steps in continuous (chemo)enzymatic cascades. Therefore, efficient covalent immobilization techniques are of utmost importance, which enable a fast and selective immobilization of the enzyme directly from crude cell extracts. Here we demonstrate that the HaloTag™ mediates the covalent immobilization of such fusion enzymes in only a few minutes contact time with the respective modified carrier in a packed-bed reactor, thereby enabling enzyme immobilization directly in the flow setup. In this study, we evaluated this concept for a continuous enzymatic cascade towards a chiral vicinal diol by combining a variant of the benzoylformate decarboxylase from Pseudomonas putida (PpBFD) and the alcohol dehydrogenase from Lactobacillus brevis (LbADH). Limitations in PpBFD stability were overcome by optimization of buffer salt, cofactor concentration and choice of a different substrate. For optimal LbADH activity, excess acetaldehyde was removed in-line. This optimization lead to a high operational stability of the individual cascade steps up to several weeks and resulting in the efficient stereoselective production of (1S,2S)-1-phenylpropane-1,2-diol with high conversion up to 99%, high stereoselectivities (ee/ic) up to 96% and space–time yields up to 1850 g L−1 d−1. [ABSTRACT FROM AUTHOR]

The nitrogen phosphotransferase system (PTSNtr) of Pseudomonas putida is a multi-component regulatory device that participates in controlling a variety of physiological processes in a post-translational fashion. A general survey of genes regulated by PtsN exposed transcription of the kdpFABC operon is most conspicuously affected. Measurements of kdpFp promoter activity in different pts mutants showed that PtsN is responsible for repression of kdpFABC transcription. This effect could be assigned mainly to PtsN~P, depending on the external K+ concentration. Bacterial two-hybrid assays demonstrated that kdpFp regulation is implemented through direct interaction of the PtsN protein with the sensor kinase KdpD of the KdpD/KdpE two-component system. Interaction between KdpD and PtsN was detectable with a PtsN variant that imitates the non-phosphorylated form as well as with a PtsN type mimicking the phosphorylated form of PtsN. These results raise a regulatory scenario in which the Kdp system is regulated by the action of PtsN through direct interaction with the sensor kinase KdpD, and the outcome of such an interaction depends on the phosphorylation state of PtsN as well as on the external K+ concentration. [ABSTRACT FROM AUTHOR]

When accounting for structural fluctuations or measurement errors, a single rigid structure may not be sufficient to represent a protein. One approach to solve this problem is to represent the possible conformations as a discrete set of observed conformations, an ensemble. In this work, we follow a different richer approach and introduce a framework for estimating probability density functions in very high dimensions and then apply it to represent ensembles of folded proteins. This proposed approach combines techniques such as kernel density estimation, maximum likelihood, cross validation, and bootstrapping. We present the underlying theoretical and computational framework and apply it to artificial data and protein ensembles obtained from molecular dynamics simulations. We compare the results with those obtained experimentally, illustrating the potential and advantages of this representation. [ABSTRACT FROM PUBLISHER]

An abstract of the article "Combining Advantages of Nature and Classic Chemistry: Enzymatic Two-Step Synthesis of Anethole-1,2 Diol," by R. Oeggl and D. Rohter is presented.

An abstract of the article "Enzyme Toolboxes & Reaction Engineering - Solutions for Applied Viocatalysis," by professor D. Rother and colleagues is presented.

An abstract of the article "Imine Reductases (IREDs) in Micro-Aqueous Reaction Systems," by Z. Maugeri and D. Rother is presented.

An abstract of the article "Exploring the Sequence-Function Space of ThDP-Dependent Enzymes," by S. Bock and colleagues is presented.