Publications by authors named "V Kren"

β-Galactosidase from Bacillus circulans ATCC 31382 (BgaD) is a biotechnologically important enzyme for the synthesis of β-galactooligosaccharides (GOS). Among its four isoforms, isoform A (BgaD-A) has distinct synthetic properties. Here, we present cryoelectron microscopy (cryo-EM) structures of BgaD-A and compare them with the known X-ray crystal structure of isoform D (BgaD-D), revealing substantial structural divergences between the two isoforms.

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The preparation of pure metabolites of bioactive compounds, particularly (poly)phenols, is essential for the accurate determination of their pharmacological profiles . Since the extraction of these metabolites from biological material is tedious and impractical, they can be synthesized enzymatically by bacterial PAPS-independent aryl sulfotransferases (ASTs). However, only a few ASTs have been studied and used for (poly)phenol sulfation.

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In this work, we report the application of Buchwald-Hartwig amination for the preparation of new derivatives of quercetin and luteolin. Our investigation delves into the impact of aniline moiety on antioxidant, and anti-inflammatory activity, cytotoxicity, and the ability of flavonoids to modulate drug-resistance mechanisms in bacteria. The anti-inflammatory activity disappeared after the introduction of aniline into the flavonoids and the cytotoxicity remained low.

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Article Synopsis
  • - The research presents a 3-step enzymatic method to convert waste chitin, found in food industry byproducts, into valuable chitooligomers with a degree of polymerization (DP) between 6 to 11.
  • - The process begins with hydrolyzing chitin using engineered fungal chitinase, followed by an extension step using a β--acetylhexosaminidase variant to enhance yields up to 57%.
  • - Finally, chitooligomers with DP 6 and 7 undergo enzymatic deacetylation, resulting in bioactive chitooligomers that could be used as natural pesticides for sustainable agriculture.
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Pulmonary hypertension is a cardiovascular disease with a low survival rate. The protein galectin-3 (Gal-3) binding β-galactosides of cellular glycoproteins plays an important role in the onset and development of this disease. Carbohydrate-based drugs that target Gal-3 represent a new therapeutic strategy in the treatment of pulmonary hypertension.

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