Search

Lignin valorization to produce functionalized materials is challenging. This study harnessed the versatile properties of lignin through a grafting reaction involving the aryl hydroxyl group of alkali lignin (AL) and enzymatically modified-alkali lignin (EMAL) using Bacillus ligninphilus-derived laccase (Lacc) L1 and C. seriivinvornas-derived dye-decolorizing peroxidase (DyP) with keratin (K) amide group. This reaction was executed utilizing an eco-friendly solvent with the aim of generating thin films. A thorough investigation was conducted, focusing on grafting AL and EMAL onto K. The incorporation of EMAL into the films enhanced tensile strength (TS) (14.8±1.8 MPa) and elongation at break (EAB) (23.7±0.3 %). Additionally, it enhanced thermal stability, suppressed the proliferation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and mitigated oxidative stress. This study introduces a novel approach for lignin valorization, offering the potential to tailor mechanical properties, antibacterial and antioxidant properties of the final material, making it sustainable substitute for petroleum-based products.

Human cytomegalovirus (HCMV) is a common herpesvirus that can severely affect transplant recipients, those with AIDS, and newborns. Existing synthetic medications face limitations, including toxicity, processing issues, and viral resistance. As part of this study, the efficacy of the extracellular enzyme laccase isolated from a widely available mushroom (Pleurotus pulmonarius) was compared to that of ganciclovir, a common antiviral, used against HCMV. The study found that laccase can synergistically inhibit HCMV replication by targeting new inhibitory sites on the UL54 protein. Viral replication requires significant energy, increasing cellular respiration. The antiviral effect of laccase was linked to reduced expression of genes regulating cellular respiration, which coincided with decreased viral DNA copies. Additionally, in silico analysis has identified a novel binding site for the laccase enzyme in the C-terminal region of HCMV DNA polymerase specifically between amino acids 1004 and 1242, which effectively obstructs the binding of the essential viral replication regulatory accessory protein UL44, thereby hindering successful replication. Molecular dynamics simulations were performed under standardized conditions mimicking a cellular environment, revealing a stable protein-protein docking complex. This study may aid in developing novel antiviral strategies by utilizing laccase's target specificity to regulate host cellular pathways against Herpesviridae., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2025 Elsevier B.V. All rights reserved.)

A direct and simple fluorescent assay for the total polyphenol determination based on the bioconjugate formed between the laccase enzyme (TvL from Trametes versicolor) and carbon nanodots (CD) is developed. One of the most used reactions for the determination of phenols is based on the enzymatic reaction of their oxidation to quinones. In this work, CD has been biofunctionalized with TvL (TvL-CD) and employed as a fluorescent label to follow the enzymatic reaction. The bioconjugate was formed and characterized by spectroscopy and microscopy. The optimal TvL-CD ratio was established. The reaction between the bioconjugate and a phenolic compound such as gallic acid (GA) was followed by monitoring the fluorescence bioconjugate decrease due to the quenching effect of the quinones generated in the enzymatic reaction. These studies confirm that bioconjugation does not inhibit the enzymatic activity and the fluorescence decrease during the enzymatic reaction is mainly due to an electron transfer processes. Based on these results, a new method for the quantitative determination of polyphenols measured as GA concentration is developed. The detection and quantification limit was found to be 7.4 and 25 μM, respectively. Subsequently, the method has been applied to the direct determination of GA in wine, juice, and rice leaf extracts., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)