Structural and Functional Characterisation of TesA - A Novel Lysophospholipase A from Pseudomonas aeruginosa

TesA from Pseudomonas aeruginosa belongs to the GDSL hydrolase family of serine esterases and lipases that possess a broad substrate- and regiospecificity. It shows high sequence homology to TAP, a multifunctional enzyme from Escherichia coli exhibiting thioesterase, lysophospholipase A, protease and arylesterase activities. Recently, we demonstrated high arylesterase activity for TesA, but only minor thioesterase and no protease activity. Here, we present a comparative analysis of TesA and TAP at the structural, biochemical and physiological levels. The crystal structure of TesA was determined at 1.9 Å and structural differences were identified, providing a possible explanation for the differences in substrate specificities. The comparison of TesA with other GDSL-hydrolase structures revealed that the flexibility of active-site loops significantly affects their substrate specificity. This assumption was tested using a rational approach: we have engineered the putative coenzyme A thioester binding site of E. coli TAP into TesA of P. aeruginosa by introducing mutations D17S and L162R. This TesA variant showed increased thioesterase activity comparable to that of TAP. TesA is the first lysophospholipase A described for the opportunistic human pathogen P. aeruginosa. The enzyme is localized in the periplasm and may exert important functions in the homeostasis of phospholipids or detoxification of lysophospholipids

Refusing Medication Therapy in Involuntary Inpatient Treatment—A Multiperspective Qualitative Study

Objective: Between June 2012 and February 2013, two decisions by the German Federal Constitutional Court restricted the so-far common practice to use involuntary medication in inpatients who were involuntarily hospitalized. Up to then, involuntary medication was justified by a judge’s decision on involuntary hospitalization. It could be applied according to clinical judgment even against the declared will of a patient. Since then, all domestic laws related to involuntary treatment had to be revised. For several months, involuntary medication was allowed only in an emergency. We were interested in the impact of the changed legal framework on the experiences of inpatients, their relatives, and clinical professionals during that time.Methods: Thirty-two interviews were analyzed qualitatively using a grounded theory methodology framework.Results: As a consequence of the restrictions to involuntary medication, special efforts by nursing and medical staff were required concerning de-escalation, ward management, and the promotion of treatment commitment in inpatients who refused medication. Family caregivers were also under strong pressure. They wanted to help and to protect their relatives, but some also welcomed the use of coercion if the patient refused treatment. Most of the interviewed patients had not even noticed that their rights to refuse medication had been strengthened. They complained primarily about the involuntary hospital stay and the associated limitations of their everyday lives. While patients and family members evaluated the refusal of medication from a biographical perspective, the mental health care professionals’ focus was on the patients’ symptoms, and they understood the situation from a professional perspective. It was obvious that, in any of the four perspectives, the problem of feeling restricted was crucial and that all groups strived to gain back their scope of action.Conclusion: The temporary ban on involuntary medication questioned the hitherto common routines in inpatient treatment, in particular when patients refused to take medication. Each of the different groups did not feel good about the situation, for different reasons, however. As a consequence, it might be indispensable to increase awareness of the different perspectives and to focus the efforts on the establishment of nonviolent treatment structures and practices

Amphiphilic Perylene-Calix[4]arene hybrids:synthesis and tunable self-assembly

The first highly water-soluble perylene–calix[4]­arene hybrid with the calixarene scaffold acting as a structure-determining central platform is presented. In this tetrahedrally shaped amphiphilic architecture the hydrophilic and hydrophobic subunits are oriented at the opposite side of the calixarene platform. The hydrophobic part contains the two perylene diimide moieties, which enable strong π–π interactions in self-assembly processes. Two hydrophilic Newkome-type dendrons provide sufficient water solubility at slightly basic conditions. The tetrahedrally shaped amphiphile displays an unprecedented aggregation behavior down to concentrations as low as 10^–7 mol L^–1. The intriguing self-assembly process of the compound in water as well as under changed polarity conditions, achieved by addition of THF, could be monitored by the complemented use of cryogenic transmission electron microscopy (cryo-TEM), UV–vis spectroscopy, and fluorescence spectroscopy. Molecular-dynamics and molecular modeling simulations helped in understanding the interplay of supramolecular and optical behavior

Directed evolution of an enantioselective Bacillus subtilis lipase

Chiral compounds are of steadily increasing importance to the chemical industry, in particular for the production of pharmaceuticals. Where do these compounds come from? Apart from natural resources, two synthetic strategies are available: asymmetric chemical catalysis using transition metal catalysts and biocatalysis using enzymes. In the latter case, screening programs have identified a number of enzymes. However, their enantioselectivity is often not high enough for a desired reaction. This problem can be solved by applying directed evolution to create enantioselective enzymes as shown here for a lipase from Bacillus subtilis. The reaction studied was the asymmetric hydrolysis of meso-1,4-diacetoxy-2-cyclopentene with the formation of chiral alcohols which were detected by electrospray ionization mass spectrometry. Iterative cycles of random mutagenesis and screening allowed the identification of several variants with improved enantioselectivities. In parallel, we have started to use X-ray structural data to simulate the Bacillus subtilis lipase A-catalyzed substrate hydrolysis by using quantum mechanical and molecular mechanical calculations. This combined approach should finally enable us to devise more efficient strategies for the directed evolution of enantioselective enzymes

Smoking in Systemic Sclerosis: a Longitudinal European Scleroderma Trials and Research Group Study

Data on the role of tobacco exposure in systemic sclerosis (SSc) severity and progression are scarce. We aimed to assess the effects of smoking on the evolution of pulmonary and skin manifestations in the EUSTAR database

A membrane-bound esterase PA2949 from Pseudomonas aeruginosa is expressed and purified from Escherichia coli

Pseudomonas aeruginosa strain 1001 produces an esterase (EstA) that can hydrolyse the racemic methyl ester of b-acetylthioisobutyrate to produce the (D)-enantiomer, which serves as a precursor of captopril, a drug used for treatment of hypertension. We show here that PA2949 from P. aeruginosa PA01, a homologue of EstA, can efficiently be expressed in an enzymatically active form in E. coli. The enzyme is membrane-associated as demonstrated by cell fractionation studies. PA2949 was purified to homogeneity after solubilisation with the nonionic detergent, Triton X-100, and was shown to possess a conserved esterase catalytic triad consisting of Ser137–His258–Asp286. Our results should allow the development of an expression and purification strategy to produce this biotechnologically relevant esterase in a pure form with a high yield

Consensus recommendations of the german consortium for hereditary breast and ovarian cancer

BACKGROUND: The German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC) has established a multigene panel (TruRisk®) for the analysis of risk genes for familial breast and ovarian cancer. SUMMARY: An interdisciplinary team of experts from the GC-HBOC has evaluated the available data on risk modification in the presence of pathogenic mutations in these genes based on a structured literature search and through a formal consensus process. KEY MESSAGES: The goal of this work is to better assess individual disease risk and, on this basis, to derive clinical recommendations for patient counseling and care at the centers of the GC-HBOC from the initial consultation prior to genetic testing to the use of individual risk-adapted preventive/therapeutic measures

Enzymes for consumer products to achieve climate neutrality

29 pags., 4 figs., 3 tabs., 1 graf.Accumulated greenhouse gas emissions are expected to increase from 36.2 Giga-tons (Gt) to 60 Gt over the next three decades. The global surface temperature has increased by¿+¿1.09¿°C since 2001, and might increase by¿+¿2.2¿°C in 2100, +3.6¿°C in 2200 and +4.6¿°C in 2500. These emissions and temperature rises cannot be reduced in their entirety, but they can be lowered by using enzymes. Enzymes are proteins that catalyze biochemical reactions that make life possible since 3.8 billion years ago. Scientists have been able to "domesticate" them in such a way that enzymes, and their engineered variants, are now key players of the circular economy. With a world production of 117 Kilo-tons and a trade of 14.5 Billion-dollars, they have the potential to annually decrease CO2 emissions by 1 to 2.5 Billion-tons (Bt), the carbon demand to synthesise chemicals by 200 Million tons (Mt), the amount of chemicals by 90¿Mt, and the economic losses derived from global warming by 0.5%, while promoting biodiversity and our planet¿s health. Our success to increase these benefits will depend on better integration of enzymatic solutions in different sectors.This study was conducted under the auspices of the FuturEnzyme Project funded by the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 101000327. MF also acknowledges Grants PID2020-112758RB-I00, PDC2021-121534-I00, and TED2021-130544B-I00 from the MCIN/AEI/10.13039/501100011033 and the European Union (“NextGenerationEU/PRTR”)

Unmanned aircraft systems as a new source of disturbance for wildlife: A systematic review.

The use of small Unmanned Aircraft Systems (UAS; also known as "drones") for professional and personal-leisure use is increasing enormously. UAS operate at low altitudes (<500 m) and in any terrain, thus they are susceptible to interact with local fauna, generating a new type of anthropogenic disturbance that has not been systematically evaluated. To address this gap, we performed a review of the existent literature about animals' responses to UAS flights and conducted a pooled analysis of the data to determine the probability and intensity of the disturbance, and to identify the factors influencing animals' reactions towards the small aircraft. We found that wildlife reactions depended on both the UAS attributes (flight pattern, engine type and size of aircraft) and the characteristics of animals themselves (type of animal, life-history stage and level of aggregation). Target-oriented flight patterns, larger UAS sizes, and fuel-powered (noisier) engines evoked the strongest reactions in wildlife. Animals during the non-breeding period and in large groups were more likely to show behavioral reactions to UAS, and birds are more prone to react than other taxa. We discuss the implications of these results in the context of wildlife disturbance and suggest guidelines for conservationists, users and manufacturers to minimize the impact of UAS. In addition, we propose that the legal framework needs to be adapted so that appropriate actions can be undertaken when wildlife is negatively affected by these emergent practices