Fucoidans from Laminaria hyperborea (LH) can be antioxidative, antiangiogenic, and anti-inflammatory. In this study, a very high-molecular weight (3700 kDa) fucoidan from LH, FucBB04, was tested regarding its bioactivity in age-related macular degeneration (AMD) models in vitro. Primary retinal pigment epithelium (RPE) from pig eyes, human uveal melanoma cell line OMM-1, and RPE cell line ARPE-19 were used. Substituents of the extract were determined with chemical analysis. Cell viability was tested with tetrazolium assay (MTT), oxidative stress was induced by H2O2 or erastin, respectively. Secreted vascular endothelial growth factor A (VEGF-A) was assessed with ELISA. Retinal pigment epithelium 65 kDa protein (RPE65) and protectin (CD59) protein expression were tested in Western blot. Cell barrier was assessed by measuring trans-epithelial electrical resistance (TEER), phagocytic ability by a fluorescence assay. Gene expression and secretion of interleukin 6 (IL-6) and interleukin 8 (IL-8) were tested in real-time PCR and ELISA. FucBB04 displayed no oxidative stress protective effects. Its effect on VEGF was inconsistent, with VEGF secretion reduced in primary RPE, but not in ARPE-19. On the other hand, Lipopolysaccharide (LPS) and polyinosinic/polycytidylic acid (PIC)-induced IL-6 or IL-8 secretion was reduced by FucBB04, while complement inhibiting protein CD59 was not affected. In addition, FucBB04 did not influence the gene expression of IL-6 or IL-8. Visual cycle protein RPE65 expression, phagocytic ability, and barrier function were reduced by FucBB04. Very high-molecular weight fucoidan from LH shows bioactivities against AMD-related pathological pathways, but adverse effects on RPE function may limit its suitability as a therapeutic compound. Smaller high-molecular weight fucoidans are recommended for further research.

N-acetylglucosamine (GlcNAc) is involved in diverse signaling pathways in dimorphic yeasts and bacteria and is related to morphogenetic switching, mating, stress, virulence, and cell death. Recently, GlcNAc has been shown to promote plant growth by shaping the bacterial soil community. However, the role of GlcNAc sensing in filamentous soil fungi has not been investigated. By using Trichoderma reesei as a model organism, we show here that GlcNAc impacts the expression of around 2100 genes. Carbohydrate metabolism, amino acid metabolism, and secondary metabolism were the three most strongly affected classes of eukaryotic orthologous groups (KOG classes). Two key regulators of GlcNAc catabolism, the NDT80 domain-containing transcriptional regulator RON1, and a GlcNAc sensor, NGS1, are needed for differential regulation of two-thirds of these genes. In silico structural modeling of NGS1 identified a domain with homology to the GCN5-related histone acetyltransferase from Candida albicans, which serves as a GlcNAc catabolism regulator and GlcNAc sensor. Finally, we characterized the third regulator of GlcNAc sensing in T. reesei, which is the highly specific GlcNAc transporter N-acetylglucosamine transporter (NGT1). Using a deletion mutant of ngt1, we demonstrate that GlcNAc has to enter the cell to activate the GlcNAc catabolic gene expression. Interestingly, in contrast to dimorphic yeasts, the pathways for defense and pathogenicity seem to be induced in T. reesei by external GlcNAc. Given the ancestral role of Trichoderma spp. in the fungal kingdom and the highly conserved GlcNAc catabolism cluster that includes their regulators in many species of fungi, we propose a regulatory network for GlcNAc sensing in soil fungi.

The growing population and environmental issues have raised concerns about food safety and sustainable production, where the use of negatively impacting traditional pesticides and agrochemicals is constantly debated. To limit environmental damage and to ensure the quantity and quality of food production, a new era of food industry is transforming to sustainable agriculture practices assisted by the use of microorganisms and biomolecular tools. Cell walls are the key structure for plant development and biomass accumulation in the form of polysaccharides and regulate the plant's relationship with the ecology. Cell wall integrity, remodeling and degradation are critical aspects of the plant-pathogen and plant-beneficial interactions and also take part in the recycling of organic matter. In this context, the use of microbial cell wall degrading enzymes (CWDEs) is a green alternative to traditional agrochemicals. This chapter discusses the different activities of CWDEs, their production and their potential application in plant productivity, protection and waste valorization.

The phylum Oomycota contains economically important pathogens of animals and plants, including Saprolegnia parasitica , the causal agent of the fish disease saprolegniasis. Due to intense fish farming and banning of the most effective control measures, saprolegniasis has re-emerged as a major challenge for the aquaculture industry. Oomycete cells are surrounded by a polysaccharide-rich cell wall matrix that, in addition to being essential for cell growth, also functions as a protective “armor.” Consequently, the enzymes responsible for cell wall synthesis provide potential targets for disease control. Oomycete cell wall biosynthetic enzymes are predicted to be plasma membrane proteins. To identify these proteins, we applied a quantitative (iTRAQ) mass spectrometry-based proteomics approach to the plasma membrane of the hyphal cells of S. parasitica , providing the first complete plasma membrane proteome of an oomycete species. Of significance is the identification of 65 proteins enriched in detergent-resistant microdomains (DRMs). In silico analysis showed that DRM-enriched proteins are mainly involved in molecular transport and β-1,3-glucan synthesis, potentially contributing to pathogenesis. Moreover, biochemical characterization of the glycosyltransferase activity in these microdomains further supported their role in β-1,3-glucan synthesis. Altogether, the knowledge gained in this study provides a basis for developing disease control measures targeting specific plasma membrane proteins in S. parasitica . The significance of this research lies in its potential to combat saprolegniasis, a detrimental fish disease, which has resurged due to intensive fish farming and regulatory restrictions. By targeting enzymes responsible for cell wall synthesis in Saprolegnia parasitica , this study uncovers potential avenues for disease control. Particularly noteworthy is the identification of several proteins enriched in membrane microdomains, offering insights into molecular mechanisms potentially involved in pathogenesis. Understanding the role of these proteins provides a foundation for developing targeted disease control measures. Overall, this research holds promise for safeguarding the aquaculture industry against the challenges posed by saprolegniasis.

The significance of this research lies in its potential to combat saprolegniasis, a detrimental fish disease, which has resurged due to intensive fish farming and regulatory restrictions. By targeting enzymes responsible for cell wall synthesis in Saprolegnia parasitica , this study uncovers potential avenues for disease control. Particularly noteworthy is the identification of several proteins enriched in membrane microdomains, offering insights into molecular mechanisms potentially involved in pathogenesis. Understanding the role of these proteins provides a foundation for developing targeted disease control measures. Overall, this research holds promise for safeguarding the aquaculture industry against the challenges posed by saprolegniasis.

Pectin methylesterases (PMEs) are enzymes that play a critical role in modifying pectins, a class of complex polysaccharides in plant cell walls. These enzymes catalyze the removal of methyl ester groups from pectins, resulting in a change in the degree of esterification and consequently, the physicochemical properties of the polymers. PMEs are found in various plant tissues and organs, and their activity is tightly regulated in response to developmental and environmental factors. In addition to the biochemical modification of pectins, PMEs have been implicated in various biological processes, including fruit ripening, defense against pathogens, and cell wall remodelling. This review presents updated information on PMEs, including their sources, sequences and structural diversity, biochemical properties and function in plant development. The article also explores the mechanism of PME action and the factors influencing enzyme activity. In addition, the review highlights the potential applications of PMEs in various industrial sectors related to biomass exploitation, food, and textile industries, with a focus on development of bioproducts based on eco-friendly and efficient industrial processes.

Biolayer interferometry (BLI) is a well-established laboratory technique for studying biomolecular interactions important for applications such as drug development. Currently, there are interesting opportunities for expanding the use of BLI in other fields, including the development of rapid diagnostic tools. To date, there are no detailed frameworks for implementing BLI in target-recognition studies that are pivotal for developing point-of-need biosensors. Here, we attempt to bridge these domains by providing a framework that connects output(s) of molecular interaction studies with key performance indicators used in the development of point-of-need biosensors. First, we briefly review the governing theory for protein-ligand interactions, and we then summarize the approach for real-time kinetic quantification using various techniques. The 2020 PRISMA guideline was used for all governing theory reviews and meta-analyses. Using the information from the meta-analysis, we introduce an experimental framework for connecting outcomes from BLI experiments (K-D, k(on), k(off)) with electrochemical (capacitive) biosensor design. As a first step in the development of a larger framework, we specifically focus on mapping BLI outcomes to five biosensor key performance indicators (sensitivity, selectivity, response time, hysteresis, operating range). The applicability of our framework was demonstrated in a study of case based on published literature related to SARS-CoV-2 spike protein to show the development of a capacitive biosensor based on truncated angiotensin-converting enzyme 2 (ACE2) as the receptor. The case study focuses on non-specific binding and selectivity as research goals. The proposed framework proved to be an important first step toward modeling/simulation efforts that map molecular interactions to sensor design.