Bioconjugates established between anionic polyethylene glycol (PEG) based polymers and cationic proteins have proven to be a promising strategy to engineer thermostable biocatalysts. However, the enzyme activity of these bioconjugates is very low and the mechanism of non-covalent PEG-stabilization is yet to be understood. This work presents experimental and molecular dynamics simulation studies, using lipase-polymer surfactant nanoconjugates from mesophile Rhizomucor miehei (RML), performed to evaluate the effect of PEG on enzyme stability and activity. Results demonstrated that the number of hydrogen bonds between the cationized RML and PEG chain correlates with enzyme thermostability. In addition, an increase of both the number of PEG-polymers units and cationization degree of the enzyme leads to a decrease of enzyme activity. Modelling with SAXS data of aqueous solutions of the biofluid lipases agrees with previous hypothesis that these enzymes contain a core constituted of folded protein confined by a shell of surfactants. Together results provide valuable insight into the mechanism of non-covalent PEG mediated protein stabilization relevant for engineering active and thermostable biofluids. Furthermore, the first biofluids RML with activity comparable to their cationized counterpart are presented.
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http://dx.doi.org/10.1038/s41598-018-29871-z | DOI Listing |
Vet Sci
September 2024
Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Department of Animal Medicine & Surgery, Veterinary School, Campus Mare Nostrum, University of Murcia, 30100 Murcia, Spain.
Metritis affects 5-20% of cows after parturition, negatively impacting animal welfare and the profitability of dairy farms, increasing culling rates and costs, and decreasing productivity and reproduction rates. This study compared the results of a comprehensive biochemical panel consisting of 25 salivary and 31 serum analytes between healthy cows ( = 16) and cows with metritis ( = 12). Descriptive parameters such as depression, rectal temperature, body condition score (BCS), heart rate, respiratory rate, mucous color, ruminal motility, vaginal discharge, milk production, and complete hematology analyses were also assessed for comparative purposes.
View Article and Find Full Text PDFJ Proteome Res
April 2024
Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University Hospital Tübingen, Tübingen 72076, Germany.
Pancreatic ductal adenocarcinoma (PDAC) is difficult to diagnose in the early stages and lacks reliable biomarkers. The scope of this project was to establish quantitative nuclear magnetic resonance (NMR) spectroscopy to comprehensively study blood serum alterations in PDAC patients. Serum samples from 34 PDAC patients obtained before and after pancreatectomy as well as 83 age- and sex-matched control samples from healthy donors were analyzed with diagnostics research (IVDr) proton NMR spectroscopy at 600 MHz.
View Article and Find Full Text PDFAdv Sci (Weinh)
November 2022
Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, Aarhus, 8000, Denmark.
The surface of a carboxylate-enriched octuple mutant of Bacillus subtilis lipase A (8M) is chemically anionized to produce core (8M)-shell (cationic polymer surfactants) bionanoconjugates in protein liquid form, which are termed anion-type biofluids. The resultant lipase biofluids exhibit a 2.5-fold increase in hydrolytic activity when compared with analogous lipase biofluids based on anionic polymer surfactants.
View Article and Find Full Text PDFPhys Chem Chem Phys
March 2021
Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
Solvent-free enzymes hold the promise of being able to deliver higher activity at elevated temperatures by virtue of them being not limited by the boiling point of the solvent. They have been realized in the liquid phase through a polymer surfactant coating on the protein surface. However, a clear understanding of intermolecular interactions, structure, dynamics, and the behaviour of the minuscule amount of water present in the solvent-free protein liquid is essential to enhance the activity of these biofluids.
View Article and Find Full Text PDFChembiochem
May 2019
Department of Engineering, Aarhus University, Gustav Wieds Vej 10, Aarhus, 8000, Denmark.
Despite a successful application of solvent-free liquid protein (biofluids) concept to a number of commercial enzymes, the technical advantages of enzyme biofluids as hyperthermal stable biocatalysts cannot be fully utilized as up to 90-99% of native activities are lost when enzymes were made into biofluids. With a two-step strategy (site-directed mutagenesis and synthesis of variant biofluids) on Bacillus subtilis lipase A (BsLA), we elucidated a strong dependency of structure and activity on the number and distribution of polymer surfactant binding sites on BsLA surface. Here, it is demonstrated that improved BsLA variants can be engineered via site-mutagenesis by a rational design, either with enhanced activity in aqueous solution in native form, or with improved physical property and increased activity in solvent-free system in the form of a protein liquid.
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