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1.
Ther Umsch ; 77(1): 3-9, 2020.
Artigo em Alemão | MEDLINE | ID: mdl-32486993

RESUMO

Opioid crisis: What now? A pain specialist's point of view Abstract. In acute pain, opioids in combination with co-analgesics can be useful and indicated. It is important to evaluate and to treat every single patient individually. Therefore, experienced patient guidance is crucial in pain treatment to reduce the risk of side effects and inappropriate long-term opioid use. The indication and doses for opioids need continuous re-evaluation. Ineffective treatments with opioids have to be tapered. Furthermore, opioid prescription should always be limited in time with a plan to taper it to prevent misuse or even addiction. Alternative medical and non-medical treatment options are important as well. The following text gives advice on how to approach a patient with pain and contains a manual on how to handle opioids in different settings.

2.
Int J Mol Sci ; 21(12)2020 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32545914

RESUMO

Tendinopathy is a rare but serious complication of quinolone therapy. Risk factors associated with quinolone-induced tendon disorders include chronic kidney disease accompanied by the accumulation of uremic toxins. Hence, the present study explored the effects of the representative uremic toxins phenylacetic acid (PAA) and quinolinic acid (QA), both alone and in combination with ciprofloxacin (CPX), on human tenocytes in vitro. Tenocytes incubated with uremic toxins +/- CPX were investigated for metabolic activity, vitality, expression of the dominant extracellular tendon matrix (ECM) protein type I collagen, cell-matrix receptor ß1-integrin, proinflammatory interleukin (IL)-1ß, and the ECM-degrading enzyme matrix metalloproteinase (MMP)-1. CPX, when administered at high concentrations (100 mM), suppressed tenocyte metabolism after 8 h exposure and at therapeutic concentrations after 72 h exposure. PAA reduced tenocyte metabolism only after 72 h exposure to very high doses and when combined with CPX. QA, when administered alone, led to scarcely any cytotoxic effect. Combinations of CPX with PAA or QA did not cause greater cytotoxicity than incubation with CPX alone. Gene expression of the pro-inflammatory cytokine IL-1ß was reduced by CPX but up-regulated by PAA and QA. Protein levels of type I collagen decreased in response to high CPX doses, whereas PAA and QA did not affect its synthesis significantly. MMP-1 mRNA levels were increased by CPX. This effect became more pronounced in the form of a synergism following exposure to a combination of CPX and PAA. CPX was more tenotoxic than the uremic toxins PAA and QA, which showed only distinct suppressive effects.

3.
J Agric Food Chem ; 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32458686

RESUMO

The addition of cheap and also readily available raw materials, such as peanut powder, to visually and chemically similar matrices is a common problem in the food industry. When peanuts are used as an adulterant, there is an additional risk of potential health hazard to consumers as a result of allergy-induced anaphylaxis. In this study, different series of peanut admixtures to visually similar food products, such as powdered hazelnuts, almonds, and walnuts, were prepared and analyzed by 1H nuclear magnetic resonance (NMR) spectroscopy. For identification, an isolated signal at 3.05 ppm in the 1H NMR spectrum of polar peanut extract was used as an indicator of peanut adulteration. The chemical marker was identified as (2S,4R)-N-methyl-4-hydroxy-l-proline by resynthesis of the compound and used as an internal standard. The signal-to-noise ratio and the integral of the signal of the marker can both be used to detect peanut impurities. Overall, an approximate limit of detection of 4% admixtures of peanut in various food products was determined using a 400 MHz spectrometer. With regard to food fraud, we present a viable screening method for detection of economic-relevant peanut adulteration.

4.
J R Soc Interface ; 17(165): 20190794, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32316880

RESUMO

Biological filaments driven by molecular motors tend to experience tangential propulsive forces also known as active follower forces. When such a filament encounters an obstacle, it deforms, which reorients its follower forces and alters its entire motion. If the filament pushes a cargo, the friction on the cargo can be enough to deform the filament, thus affecting the transport properties of the cargo. Motivated by cytoskeletal filament motility assays, we study the dynamic buckling instabilities of a two-dimensional slender elastic filament driven through a dissipative medium by tangential propulsive forces in the presence of obstacles or cargo. We observe two distinct instabilities. When the filament's head is pinned or experiences significant translational but little rotational drag from its cargo, it buckles into a steadily rotating coiled state. When it is clamped or experiences both significant translational and rotational drag from its cargo, it buckles into a periodically beating, overall translating state. Using minimal analytically tractable models, linear stability theory and fully nonlinear computations, we study the onset of each buckling instability, characterize each buckled state, and map out the phase diagram of the system. Finally, we use particle-based Brownian dynamics simulations to show our main results are robust to moderate noise and steric repulsion. Overall, our results provide a unified framework to understand the dynamics of tangentially propelled filaments and filament-cargo assemblies.

5.
Anesthesiology ; 132(3): 571-580, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31809325

RESUMO

BACKGROUND: Open label placebos with patient education are effective in reducing chronic pain, and recent studies on their effect on pain have established interest in this field. Nevertheless, data on their effect on acute pain are scarce, and on hyperalgesia and allodynia, absent. This study assessed the effect of open label placebos on acute pain in healthy adult males and the influence of placebo education. METHODS: Thirty-two healthy males were included in this prospective, randomized, assessor-blinded crossover, single-center study assessing pain intensities (via numeric rating scale), area of hyperalgesia (von Frey filament), and allodynia (dry cotton swab) in a pain model utilizing intracutaneous electrical stimulation. The authors compared the effect of intravenous open label placebo on pain compared to no treatment. The authors further examined the effect of placebo on hyperalgesia and allodynia, and the influence of education (short vs. detailed) before placebo application. Saliva cortisol concentrations were also measured. RESULTS: Pain ratings (median, first to third quartile) were 21% lower during placebo treatment compared to no treatment, 4.0 (3.2 to 4.9) versus 5.1 (4.7 to 5.4), respectively (P = 0.001). The areas of hyperalgesia and allodynia were lower during placebo treatment compared to no treatment (hyperalgesia, 30 cm [17 to 47] vs. 55 cm [42 to 68], P = 0.003; allodynia, 24 cm [11 to 39] vs. 45 cm [31 to 62], P = 0.007). This corresponds to reductions of 47%. The extent of placebo education had no effect on pain. Saliva cortisol decreased significantly over time and was under the limit of detectability in the majority of participants in postbaseline measurements in both treatment branches. Baseline cortisol was not associated with the placebo effect or strength applied of current to reach defined pain ratings. CONCLUSIONS: Open label placebos might play a role in multimodal analgesic concepts.

7.
Sci Rep ; 9(1): 19991, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882959

RESUMO

Ubiquitylation is an eminent posttranslational modification referring to the covalent attachment of single ubiquitin molecules or polyubiquitin chains to a target protein dictating the fate of such labeled polypeptide chains. Here, we have biochemically produced artificially Lys11-, and Lys27-, and Lys63-linked ubiquitin dimers based on click-chemistry generating milligram quantities in high purity. We show that the artificial linkage used for the conjugation of two ubiquitin moieties represents a fully reliable surrogate of the natural isopeptide bond by acquiring highly resolved nuclear magnetic resonance (NMR) spectroscopic data including ligand binding studies. Extensive coarse grained and atomistic molecular dynamics (MD) simulations allow to extract structures representing the ensemble of domain-domain conformations used to verify the experimental data. Advantageously, this methodology does not require individual isotopic labeling of both ubiquitin moieties as NMR data have been acquired on the isotopically labeled proximal moiety and complementary MD simulations have been used to fully interpret the experimental data in terms of domain-domain conformation. This combined approach intertwining NMR spectroscopy with MD simulations makes it possible to describe the conformational space non-canonically Lys11-, and Lys27-linked ubiquitin dimers occupy in a solution averaged ensemble by taking atomically resolved information representing all residues in ubiquitin dimers into account.

8.
Small ; 15(49): e1904315, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31709700

RESUMO

The magnetization dynamics of individual Fe-filled multiwall carbon-nanotubes (FeCNT), grown by chemical vapor deposition, are investigated by microresonator ferromagnetic resonance (FMR) and Brillouin light scattering (BLS) microscopy and corroborated by micromagnetic simulations. Currently, only static magnetometry measurements are available. They suggest that the FeCNTs consist of a single-crystalline Fe nanowire throughout the length. The number and structure of the FMR lines and the abrupt decay of the spin-wave transport seen in BLS indicate, however, that the Fe filling is not a single straight piece along the length. Therefore, a stepwise cutting procedure is applied in order to investigate the evolution of the ferromagnetic resonance lines as a function of the nanowire length. The results show that the FeCNT is indeed not homogeneous along the full length but is built from 300 to 400 nm long single-crystalline segments. These segments consist of magnetically high quality Fe nanowires with almost the bulk values of Fe and with a similar small damping in relation to thin films, promoting FeCNTs as appealing candidates for spin-wave transport in magnonic applications.

9.
Phys Rev E ; 100(3-1): 031102, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31640040

RESUMO

Spatially localized invariant solutions of plane Couette flow are organized in a snakes-and-ladders structure strikingly similar to that observed for simpler pattern-forming partial differential equations [Schneider, Gibson, and Burke, Phys. Rev. Lett. 104, 104501 (2010)PRLTAO0031-900710.1103/PhysRevLett.104.104501]. We demonstrate the mechanism by which these snaking solutions originate from well-known periodic states of the Taylor-Couette system. They are formed by a localized slug of wavy-vortex flow that emerges from a background of Taylor vortices via a modulational sideband instability. This mechanism suggests a close connection between pattern-formation theory and Navier-Stokes flow.

10.
Vaccine ; 37(47): 7070-7080, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31300289

RESUMO

Polymer-grafted chromatography media, especially ion exchangers, are high performance materials for protein purification. However, due to the pore size limitation, conventional chromatography beads are usually not considered for the downstream processing of large biomolecules such as virus-like particles (VLPs). Contrariwise, since the outer surface of the chromatography beads provides satisfactory binding capacity for VLPs and impurities of smaller size can bind inside of the beads, conventional porous beads should be considered for VLP capture and purification. We used HIV-1 gag VLPs with a diameter of 100-200 nm as a model to demonstrate that polymer-grafted anion exchangers are suitable for the purification of bionanoparticles. The equilibrium binding capacity was 1 × 1013 part/mL resin. Moderate salt concentration up to 100 mM NaCl did not affect binding, allowing direct loading of cell culture supernatant onto the column for purification. Dynamic binding capacity at 10% breakthrough, when loading cell culture supernatant, was approximately 6 × 1011 part/mL column; only 1-log lower than for monoliths. Endonuclease treatment of the cell culture supernatant did not increase the dynamic binding capacity, suggesting that dsDNA does not compete for the binding sites of VLPs. Nevertheless, due to simultaneous elution of particles and dsDNA, endonuclease treatment is required to reduce dsDNA contamination in the product. Proteomic analysis revealed that HIV-1 gag VLPs contain different host cell proteins in their cargo. This cargo is composed of conserved proteins and other proteins that vary from one particle population to another, as well as from batch to batch. This process allowed the separation of different particle populations. HIV-1 gag VLPs were directly captured and purified from cell culture supernatant with a total particle recovery in the elution of about 35%. Columns packed with beads can be scaled to practically any dimension and therefore a tailored design of the process is possible.

11.
Sci Total Environ ; 685: 806-817, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31238284

RESUMO

Lake Lugano is one of several deep lakes in Switzerland that have not yet recovered from eutrophication after large reductions of external phosphorus (P) loadings. Persistent eutrophication has been attributed mainly to internal P loadings from sediments. To achieve the restoration goals, it is critically important to evaluate the sediment P availability and release risk in this lake. In this study, we combined sequential P extraction (four fractions) with enzyme hydrolysis to assess distribution characteristics of P forms and potential bioavailability of organic P in an anoxic sediment profile from the Ponte Tresa basin of Lake Lugano, southern Switzerland. Labile P forms, i.e. mostly redox-sensitive iron bound P and metal oxides bound P (Al/Fe-P), comprised ~70% of total P in the sediment profile (1959-2017 CE), suggesting a high potential for P release from the anoxic sediment. Potentially bioavailable organic P forms (determined by addition of substrate specific enzymes) were considerably higher in the surface sediments (top 5 cm), which is very likely to release P in the near future with early diagenesis. The net burial rates (NBR) of redox sensitive Fe-P fraction and total P in sediments both showed significant decreasing trends from 1959 to 2017 CE, when trophic levels of the lake increased from mesotrophic to hypertrophic status. We suggest that, in the Ponte Tresa basin, higher eutrophication conditions led to enhanced sediment P release (mainly from redox sensitive Fe-P fraction), thus reducing P-NBR in sediments. This study highlights the concern that in deep monomictic lakes, eutrophication restoration might be hindered by extensive internal P cycling and reduced capacity of sediment P-trapping.


Assuntos
Monitoramento Ambiental , Fósforo/análise , Poluentes Químicos da Água/análise , Eutrofização , Lagos/química , Suíça
12.
Lab Chip ; 19(13): 2220-2232, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31157806

RESUMO

The high-throughput selection of individual droplets is an essential function in droplet-based microfluidics. Fluorescence-activated droplet sorting is achieved using electric fields triggered at rates up to 30 kHz, providing the ultra-high throughput relevant in applications where large libraries of compounds or cells must be analyzed. To achieve such sorting frequencies, electrodes have to create an electric field distribution that generates maximal actuating forces on the droplet while limiting the induced droplet deformation and avoid disintegration. We propose a metric characterizing the performance of an electrode design relative to the theoretical optimum and analyze existing devices using full 3D simulations of the electric fields. By combining parameter optimization with numerical simulation we derive rational design guidelines and propose optimized electrode configurations. When tested experimentally, the optimized design show significantly better performance than the standard designs.

13.
J Sep Sci ; 42(16): 2640-2649, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31169979

RESUMO

At-line static light scattering and fluorescence monitoring allows direct in-process tracking of fluorescent virus-like particles. We have demonstrated this by coupling at-line multi-angle light scattering and fluorescence detectors to the downstream processing of enveloped virus-like particles. Since light scattering intensity is directly proportional to particle concentration, our strategy allowed a swift identification of product containing fractions and rapid process development. Virus-like particles containing the Human Immunodeficiency Virus-1 Gag protein fused to the Green Fluorescence protein were produced in Human Embryonic Kidney 293 cells by transient transfection. A single-column anion-exchange chromatography method was used for direct capture and purification. The majority of host-cell protein impurities passed through the column without binding. Virus-like particles bound to the column were eluted by linear or step salt gradients. Particles recovered in the step gradient purification were characterized by nanoparticle tracking analysis, size exclusion chromatography coupled to multi-angle light scattering and fluorescence detectors and transmission electron microscopy. A total recovery of 66% for the fluorescent particles was obtained with a 50% yield in the main product peak. Virus-like particles were concentrated 17-fold to final a concentration of 4.45 × 1010 particles/mL. Simple buffers and operation make this process suitable for large scale purposes.


Assuntos
Luz , Vírion/isolamento & purificação , Produtos do Gene gag do Vírus da Imunodeficiência Humana/isolamento & purificação , Células Cultivadas , Cromatografia , Células HEK293 , Humanos , Nanopartículas/química , Espalhamento de Radiação , Vírion/química , Produtos do Gene gag do Vírus da Imunodeficiência Humana/química
14.
Nat Commun ; 10(1): 2277, 2019 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-31123255

RESUMO

Wall-bounded shear flows transitioning to turbulence may self-organize into alternating turbulent and laminar regions forming a stripe pattern with non-trivial oblique orientation. Different experiments and flow simulations identify oblique stripe patterns as the preferred solution of the well-known Navier-Stokes equations, but the origin of stripes and their oblique orientation remains unexplained. In concluding his lectures, Feynman highlights the unexplained stripe pattern hidden in the solution space of the Navier-Stokes equations as an example demonstrating the need for improved theoretical tools to analyze the fluid flow equations. Here we exploit dynamical systems methods and demonstrate the existence of an exact equilibrium solution of the fully nonlinear 3D Navier-Stokes equations that resembles oblique stripe patterns in plane Couette flow. The stripe equilibrium emerges from the well-studied Nagata equilibrium and exists only for a limited range of pattern angles. This suggests a mechanism selecting the non-trivial oblique orientation angle of turbulent-laminar stripes.

15.
Swiss Med Wkly ; 149: w20073, 2019 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-30994924

RESUMO

AIMS OF THE STUDY: Given the long history of underestimating chronic pain in children and adolescents, we lack valid data on its assessment and treatment. The psychological and economic burden for patients, their families and society is substantial. The aim of this study was to assess patient characteristics of the first ambulatory interdisciplinary clinic for children and adolescents with chronic pain in Switzerland and compare them with data from other international centres. METHODS: All patients of the ambulatory interdisciplinary pain clinic at the University Children’s Hospital in Basel during the period from 4 January 2012 to 4 July 2016 were included in this retrospective study. Data were collected from the patients’ medical records and from a questionnaire, which the patients and their parents received and completed in advance of their first visit. Demographic information, pain, referral, social environment, therapies and school absences of the patients were statistically analysed with means, percentages, 95% confidence intervals (CIs) and standard deviations (SDs). RESULTS: Of the 135 patients included in this study, 80% were female and the mean age of all patients was 13.95 years (95% CI 13.5–14.4). The commonest pain presentations were: musculoskeletal (38%, 95% CI 0.30–0.46), back (25%, 95% CI 0.18–0.33), multiple regions (21%, 95% CI 0.15–0.28) and headache (7%, 95% CI 0.03–0.12). Mean duration of pain until the patients came to the clinic was 24.5 months (95% CI 19.82–29.22). Physiotherapy (71%, 95% CI 0.63–0.79) and non-opioids (50%, 95% CI 0.42–0.59) were the most used therapies before the first meeting. Psychotherapy (52%, 95% CI 0.44–0.61), most often using a psychosomatic therapeutic approach (psychosomatic therapy) 34% (95% CI 0.26–0.42), physiotherapy (36%, 95% CI 0.27–0.44) and non-opioids (33%, 95% CI 0.25–0.42) afterwards. The mean number of school absences during the last month before the first visit was 5.1 days per month (95% CI 3.48–6.73). The parents of our study participants suffered more often from psychiatric diseases than the mean Swiss population. CONCLUSIONS: The average of more than 2 years of pain before referral to the clinic seems to be a long time. Assuming that specialised support is mandatory for young patients with complex pain syndromes, the referral time should be reduced. Furthermore, patients with headache were underrepresented in Basel compared with other centres. Interestingly, in our study, patients’ parents suffered more often from psychiatric diseases than the mean Swiss population.


Assuntos
Dor Crônica/terapia , Clínicas de Dor/estatística & dados numéricos , Manejo da Dor/estatística & dados numéricos , Equipe de Assistência ao Paciente , Encaminhamento e Consulta/estatística & dados numéricos , Adolescente , Criança , Feminino , Hospitais Pediátricos , Hospitais Universitários , Humanos , Masculino , Manejo da Dor/métodos , Estudos Retrospectivos , Suíça , Tempo para o Tratamento/estatística & dados numéricos
16.
Front Plant Sci ; 10: 437, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31024601

RESUMO

Recently, several plant-made recombinant proteins received favorable regulatory review as food antibacterials in the United States through the Generally Recognized As Safe (GRAS) regulatory procedure, and applications for others are pending. These food antimicrobials, along with approved biopharmaceuticals and vaccines, represent new classes of products manufactured in green plants as production hosts. We present results of new research and development and summarize regulatory, economic and business aspects of the antibacterial proteins colicins and salmocins as new food processing aids.

17.
Chembiochem ; 20(14): 1772-1777, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-30920720

RESUMO

As one of the most prevalent post-translational modifications in eukaryotic cells, ubiquitylation plays vital roles in many cellular processes, such as protein degradation, DNA metabolism, and cell differentiation. Substrate proteins can be tagged by distinct types of polymeric ubiquitin (Ub) chains, which determine the eventual fate of the modified protein. A facile, click chemistry based approach for the efficient generation of linkage-defined Ub chains, including Ub dimers, was recently established. Within these chains, individual Ub moieties are connected through a triazole linkage, rather than the natural isopeptide bond. Herein, it is reported that the conformation of an artificially K48-linked Ub dimer resembles that of the natively linked dimer, with respect to structural and dynamic characteristics, as demonstrated by means of high-resolution NMR spectroscopy. Thus, it is proposed that artificially linked Ub dimers, as generated by this approach, represent potent tools for studying the inherently different properties and functions of distinct Ub chains.

18.
Chembiochem ; 20(17): 2163-2190, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-30830997

RESUMO

Catechols are a biologically relevant group of aromatic diols that have attracted much attention as mediators of adhesion of "bio-glue" proteins in mussels of the genus Mytilus. These organisms use catechols in the form of the noncanonical amino acid l-3,4-dihydroxyphenylalanine (DOPA) as a building block for adhesion proteins. The DOPA is generated post-translationally from tyrosine. Herein, we review the properties, natural occurrence, and reactivity of catechols in the design of bioinspired materials. We also provide a basic description of the mussel's attachment apparatus, the interplay between its different molecules that play a crucial role in adhesion, and the role of post-translational modifications (PTMs) of these proteins. Our focus is on the microbial production of mussel foot proteins with the aid of orthogonal translation systems (OTSs) and the use of genetic code engineering to solve some fundamental problems in the bioproduction of these bioadhesives and to expand their chemical space. The major limitation of bacterial expression systems is their intrinsic inability to introduce PTMs. OTSs have the potential to overcome these challenges by replacing canonical amino acids with noncanonical ones. In this way, PTM steps are circumvented while the genetically programmed precision of protein sequences is preserved. In addition, OTSs should enable spatiotemporal control over the complex adhesion process, because the catechol function can be masked by suitable chemical protection. Such caged residues can then be noninvasively unmasked by, for example, UV irradiation or thermal treatment. All of these features make OTSs based on genetic code engineering in reprogrammed microbial strains new and promising tools in bioinspired materials science.

19.
Nat Nanotechnol ; 14(4): 328-333, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30804478

RESUMO

Spin waves offer intriguing perspectives for computing and signal processing, because their damping can be lower than the ohmic losses in conventional complementary metal-oxide-semiconductor (CMOS) circuits. Magnetic domain walls show considerable potential as magnonic waveguides for on-chip control of the spatial extent and propagation of spin waves. However, low-loss guidance of spin waves with nanoscale wavelengths and around angled tracks remains to be shown. Here, we demonstrate spin wave control using natural anisotropic features of magnetic order in an interlayer exchange-coupled ferromagnetic bilayer. We employ scanning transmission X-ray microscopy to image the generation of spin waves and their propagation across distances exceeding multiples of the wavelength. Spin waves propagate in extended planar geometries as well as along straight or curved one-dimensional domain walls. We observe wavelengths between 1 µm and 150 nm, with excitation frequencies ranging from 250 MHz to 3 GHz. Our results show routes towards the practical implementation of magnonic waveguides in the form of domain walls in future spin wave logic and computational circuits.

20.
Biotechnol J ; 14(4): e1800272, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30430764

RESUMO

Synthetic plastics such as polyethylene terephthalate (PET) can be cooperatively degraded by microbial polyester hydrolases and carboxylesterases, with the latter hydrolyzing the low-molecular-weight degradation intermediates. For the identification of PET-degrading enzymes, efficient and rapid screening assays are required. Here a novel turbidimetric method in a microplate format for the fast screening of enzyme activities against the PET model substrates with two ester bonds bis-(2-hydroxyethyl) terephthalate (BHET) and ethylene glycol bis-(p-methylbenzoate) (2PET) is reported. The carboxylesterase TfCa from Thermobifida fusca KW3 is used for validating the method. High correlation and regression coefficients between the experimental and fitted data confirm the accuracy and reproducibility of the method and its feasibility for analyzing the kinetics of the enzymatic hydrolysis of the PET model substrates. A comparison of the hydrolysis of BHET and 2PET by TfCa using a kinetic model for heterogeneous catalysis indicates that the enzyme preferentially hydrolyzes the less bulky molecule BHET. The high-throughput assay will facilitate the detection of novel enzymes for the biocatalytic modification or degradation of PET.


Assuntos
Actinomycetales/enzimologia , Carboxilesterase/química , Hidrolases/química , Polietilenotereftalatos/química , Actinomycetales/química , Benzoatos/química , Biocatálise , Hidrólise , Cinética , Especificidade por Substrato
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