Int J Environ Res Public Health
August 2020
While food insecurity (FI) has been extensively studied in many countries, there have been few empirical contributions in Poland to date. The main objective of our research was to identify the socio-demographic factors affecting the risk of FI in Poland within 2014-2019. Moreover, we aimed to examine the effects of the family-oriented social program "Family 500+" by comparing the situation in various types of households with children a few years before and after the program was launched.
View Article and Find Full Text PDFXylose isomerase from Piromyces sp. E2 (PirXI) can be used to equip Saccharomyces cerevisiae with the capacity to ferment xylose to ethanol. The biochemical properties and structure of the enzyme have not been described even though its metal content, catalytic parameters, and expression level are critical for rapid xylose utilization.
View Article and Find Full Text PDFRegio- and stereoselective Baeyer-Villiger oxidations are difficult to achieve by classical chemical means, particularly when large, functionalized molecules are to be converted. Biocatalysis using flavin-containing Baeyer-Villiger monooxygenases (BVMOs) is a well-established tool to address these challenges, but known BVMOs have shortcomings in either stability or substrate selectivity. We characterized a novel BVMO from the thermophilic fungus Thermothelomyces thermophila, determined its three-dimensional structure, and demonstrated its use as a promising biocatalyst.
View Article and Find Full Text PDFBy a targeted enzyme engineering approach, we were able to create an efficient NADPH oxidase from a monooxygenase. Intriguingly, replacement of only one specific single amino acid was sufficient for such a monooxygenase-to-oxidase switch-a complete transition in enzyme activity. Pre-steady-state kinetic analysis and elucidation of the crystal structure of the C65D PAMO mutant revealed that the mutation introduces small changes near the flavin cofactor, resulting in a rapid decay of the peroxyflavin intermediate.
View Article and Find Full Text PDFBaeyer-Villiger monooxygenase-catalysed reactions are attractive for industrial processes. Here we report on expanding the substrate scope of phenylacetone monooxygenase (PAMO). In order to introduce activity on alicyclic ketones in PAMO, we generated and screened a library of 1,500 mutants.
View Article and Find Full Text PDFThe presence of several putative Baeyer-Villiger Monooxygenases (BVMOs) encoding genes in Aspergillus fumigatus Af293 was demonstrated for the first time. One of the identified BVMO-encoding genes was cloned and successfully overexpressed fused to the cofactor regenerating enzyme phosphite dehydrogenase (PTDH). The enzyme named BVMOAf1 was extensively characterized in terms of its substrate scope and essential kinetic features.
View Article and Find Full Text PDFBaeyer-Villiger monooxygenases (BVMOs) have been receiving increasing attention as enzymes useful for biocatalytic applications. Industrial requirements call for rapid and extensive redesign of these enzymes. In response to the need for screening large libraries of BVMO mutants, we established a generic screening method that allows screening of Escherichia coli cells expressing active BVMOs in 96-well plate format.
View Article and Find Full Text PDFBackground: Baeyer-Villiger monooxygenases (BVMOs) represent a group of enzymes of considerable biotechnological relevance as illustrated by their growing use as biocatalyst in a variety of synthetic applications. However, due to their increased use the reproducible expression of BVMOs and other biotechnologically relevant enzymes has become a pressing matter while knowledge about the factors governing their reproducible expression is scattered.
Results: Here, we have used phenylacetone monooxygenase (PAMO) from Thermobifida fusca, a prototype Type I BVMO, as a model enzyme to develop a stepwise strategy to optimize the biotransformation performance of recombinant E.
Baeyer-Villiger monooxygenases catalyze oxidations that are of interest for biocatalytic applications. Among these enzymes, phenylacetone monooxygenase (PAMO) from Thermobifida fusca is the only protein showing remarkable stability. While related enzymes often present a broad substrate scope, PAMO accepts only a limited number of substrates.
View Article and Find Full Text PDFBaeyer-Villiger monooxygenases catalyze the oxidation of carbonylic substrates to ester or lactone products using NADPH as electron donor and molecular oxygen as oxidative reactant. Using protein engineering, kinetics, microspectrophotometry, crystallography, and intermediate analogs, we have captured several snapshots along the catalytic cycle which highlight key features in enzyme catalysis. After acting as electron donor, the enzyme-bound NADP(H) forms an H-bond with the flavin cofactor.
View Article and Find Full Text PDFType I Baeyer-Villiger monooxygenases (BVMOs) strongly prefer NADPH over NADH as an electron donor. In order to elucidate the molecular basis for this coenzyme specificity, we have performed a site-directed mutagenesis study on phenylacetone monooxygenase (PAMO) from Thermobifida fusca. Using sequence alignments of type I BVMOs and crystal structures of PAMO and cyclohexanone monooxygenase in complex with NADP(+), we identified four residues that could interact with the 2'-phosphate moiety of NADPH in PAMO.
View Article and Find Full Text PDFCurr Opin Chem Biol
April 2010
Baeyer-Villiger monooxygenases For many enzyme classes, a wealth of information on, for example, structure and mechanism has been generated in the last few decades. While the first Baeyer-Villiger monooxygenases (BVMOs) were already isolated more than 30 years ago, detailed data on these enzymes were lacking until recently. Over the last years several major scientific breakthroughs, including the elucidation of BVMO crystal structures and the identification of numerous novel BVMOs, have boosted the research on BVMOs.
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