Publications

@article{LINDNER2025122725,

title = {Three intertwining effects guide the mode of action of chitin deacetylase de- and N-acetylation reactions},

author = {Sandra Lindner and Martin Bonin and Margareta J. Hellmann and Bruno M. Moerschbacher},

url = {https://www.sciencedirect.com/science/article/pii/S0144861724009512},

doi = {https://doi.org/10.1016/j.carbpol.2024.122725},

issn = {0144-8617},

year  = {2024},

date = {2024-09-23},

urldate = {2024-09-23},

journal = {Carbohydr. Polym},

volume = {347},

pages = {122725},

abstract = {Chitosans are promising multi-functional biomolecules for various applications whose performance is dependent on three key structural parameters, including the pattern of acetylation (PA). To date, chitin deacetylases (CDAs) are the only tool to control the PA of chitosan polymers via their specific mode of action during de- or N-acetylation. For a start, this review summarizes the current state of research on the classification of carbohydrate esterase 4 enzymes, the features in sequence and structure of CDAs, and the different PAs produced by different CDAs during de- or N-acetylation. In the main part, we introduce three effects that guide the mode of action of these enzymes: the already established subsite capping effect, the subsite occupation effect, and the subsite preference effect. We show how their interplay controls the PA of CDA products and describe their molecular basis. For one thing, this review aims to equip the reader with the knowledge to understand and analyze CDAs – including a guide for in silico and in vitro analyses. But more importantly, we intend to reform and extend the model explaining their mode of action on chitosans to facilitate a deeper understanding of these important enzymes for biology and biotechnology.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid39107282,

title = {Heterogeneously deacetylated chitosans possess an unexpected regular pattern favoring acetylation at every third position},

author = {Margareta J Hellmann and Dominique Gillet and Stéphane Trombotto and Sonja Raetz and Bruno M Moerschbacher and Stefan Cord-Landwehr},

url = {https://www.nature.com/articles/s41467-024-50857-1},

doi = {10.1038/s41467-024-50857-1},

issn = {2041-1723},

year  = {2024},

date = {2024-08-01},

urldate = {2024-08-01},

journal = {Nat Commun},

volume = {15},

pages = {6695},

abstract = {Chitosans are promising biopolymers for diverse applications, with material properties and bioactivities depending i.a. on their pattern of acetylation (PA). Commercial chitosans are typically produced by heterogeneous deacetylation of chitin, but whether this process yields chitosans with a random or block-wise PA has been debated for decades. Using a combination of recently developed in vitro assays and in silico modeling surprisingly revealed that both hypotheses are wrong; instead, we found a more regular PA in heterogeneously deacetylated chitosans, with acetylated units overrepresented at every third position in the polymer chain. Compared to random-PA chitosans produced by homogeneous deacetylation of chitin or chemical N-acetylation of polyglucosamine, this regular PA increases the elicitation activity in plants, and generates different product profiles and distributions after enzymatic and chemical cleavage. A regular PA may be beneficial for some applications but detrimental for others, stressing the relevance of the production process for product development.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/anie.202410634b,

title = {Enzyme-triggered assembly of glycan nanomaterials},

author = {Jacobus P. Trijp and Nives Hribernik and Jia Hui Lim and Marlene C. S. Dal Colle and Yadiel Vázquez Mena and Yu Ogawa and Martina Delbianco},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202410634},

doi = {https://doi.org/10.1002/anie.202410634},

issn = {1433-7851},

year  = {2024},

date = {2024-07-15},

urldate = {2024-07-15},

journal = {Angew. Chem., Int. Ed},

volume = {63},

pages = {e202410634},

abstract = {A comprehensive molecular understanding of carbohydrate aggregation is key to optimize carbohydrate utilization and to engineer bioinspired analogues with tailored shape1s and properties. However, the lack of well-defined synthetic standards has substantially hampered advances in this field. Herein, we employ a phosphorylation-assisted strategy to synthesize previously inaccessible long oligomers of cellulose, chitin, and xylan. These oligomers were subjected to enzyme-triggered assembly (ETA) for the on-demand formation of well-defined carbohydrate nanomaterials, including elongated platelets, helical bundles, and hexagonal particles. Cryo-electron microscopy and electron diffraction analysis provided molecular insights into the aggregation behavior of these oligosaccharides, establishing a direct connection between the resulting morphologies and the oligosaccharide primary sequence. Our findings demonstrate that ETA is a powerful approach to elucidate the intrinsic aggregation behavior of carbohydrates in nature. Moreover, the ability to access a diverse array of morphologies, expanded with a non-natural sequence, underscores the potential of ETA, coupled with sequence design, as a robust tool for accessing programmable glycan architectures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid38341520,

title = {Fast insights into chitosan-cleaving enzymes by simultaneous analysis of polymers and oligomers through size exclusion chromatography},

author = {Margareta J Hellmann and Bruno M Moerschbacher and Stefan Cord-Landwehr},

url = {https://www.nature.com/articles/s41598-024-54002-2},

doi = {10.1038/s41598-024-54002-2},

issn = {2045-2322},

year  = {2024},

date = {2024-02-01},

urldate = {2024-02-01},

journal = {Sci Rep},

volume = {14},

pages = {3417},

abstract = {The thorough characterization of chitosan-cleaving enzymes is crucial to unveil structure-function relationships of this promising class of biomolecules for both, enzymatic fingerprinting analyses and to use the enzymes as biotechnological tools to produce tailor-made chitosans for diverse applications. Analyzing polymeric substrates as well as oligomeric products has been established as an effective way to understand the actions of enzymes, but it currently requires separate, rather laborious methods to obtain the full picture. Here, we present ultra high performance size exclusion chromatography coupled to refractive index and mass spectrometry detection (UHPSEC-RI-MS) as a straightforward method for the semi-quantitative analysis of chitosan oligomers of up to ten monomers in length. Additionally, the method allows to determine the average molecular weight of the remaining polymers and its distribution. By sampling live from an ongoing enzymatic reaction, UHPSEC-RI-MS offers the unique opportunity to analyze polymers and oligomers simultaneously-i.e., to monitor the molecular weight reduction of the polymeric substrate over the course of the digestion, while at the same time analyzing the emerging oligomeric products in a semi-quantitative manner. In this way, a single simple analysis yields detailed insights into an enzyme's action on a given substrate.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RN7,

title = {Advances in understanding insect chitin biosynthesis},

author = {A. Yu and M. Beck and H. Merzendorfer and Q. Yang},

url = {https://www.ncbi.nlm.nih.gov/pubmed/38072083},

doi = {10.1016/j.ibmb.2023.104058},

issn = {0965-1748},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Insect Biochem Mol Biol},

volume = {164},

pages = {104058},

abstract = {Chitin, a natural polymer of N-acetylglucosamine chains, is a principal component of the apical extracellular matrix in arthropods. Chitin microfibrils serve as structural components of natural biocomposites present in the extracellular matrix of a variety of invertebrates including sponges, molluscs, nematodes, fungi and arthropods. In this review, we summarize the frontier advances of insect chitin synthesis. More specifically, we focus on the chitin synthase (CHS), which catalyzes the key biosynthesis step. CHS is also known as an attractive insecticidal target in that this enzyme is absent in mammals, birds or plants. As no insect chitin synthase structure have been reported so far, we review recent studies on glycosyltransferase domain structures derived from fungi and oomycetes, which are conserved in CHS from all species containing chitin. Auxiliary proteins, which coordinate with CHS in chitin biosynthesis and assembly, are also discussed. },

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RABADIYA2024104071,

title = {The biology of insect chitinases and their roles at chitinous cuticles},

author = {Dhyeykumar Rabadiya and Matthias Behr},

url = {https://www.sciencedirect.com/science/article/pii/S096517482400002X},

doi = {https://doi.org/10.1016/j.ibmb.2024.104071},

issn = {0965-1748},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Insect Biochem Mol Biol},

volume = {165},

pages = {104071},

abstract = {Chitin is one of the most prevalent biomaterials in the natural world. The chitin matrix formation and turnover involve several enzymes for chitin synthesis, maturation, and degradation. Sequencing of the Drosophila genome more than twenty years ago revealed that insect genomes contain a number of chitinases, but why insects need so many different chitinases was unclear. Here, we focus on insect GH18 family chitinases and discuss their participation in chitin matrix formation and degradation. We describe their variations in terms of temporal and spatial expression patterns, molecular function, and physiological consequences at chitinous cuticles. We further provide insight into the catalytic mechanisms by discussing chitinase protein domain structures, substrate binding, and enzymatic activities with respect to structural analysis of the enzymatic GH18 domain, substrate-binding cleft, and characteristic TIM-barrel structure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Urca2024NanoscaleMA,

title = {Nanoscale mesh acts as anti-adhesive surface against particulate contamination in eyes of whiteflies},

author = {Tomer Urca and Fritz-Olaf Lehmann and Elena V. Gorb and Stanislav N. Gorb},

url = {https://api.semanticscholar.org/CorpusID:271743699},

doi = {10.1038/s41598-024-69059-2},

issn = {2045-2322},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Sci Rep},

volume = {14},

abstract = {In many insects the surface of the eye is nanostructured by arrays of protuberances termed ommatidial gratings which provide the cuticle with anti-reflective, anti-wetting and self-cleaning properties. The hypothesised anti-contamination role of the gratings against dust and pollen results from theoretical predictions on grating geometry and experiments on synthetic replicas of ommatidia surfaces but has not yet been proven in an animal. Whiteflies are biological test beds for anti-contamination surfaces because they deliberately distribute wax particles extruded from abdominal plates over their entire bodies. The numerous particles protect the animal against water evaporation and radiation, but may severely impair vision. Using scanning electron microscopy (SEM) and CryoSEM, we here show that the cornea of whiteflies exhibits ~ 220 nm wide mesh-like structures forming hexagonal gratings with thin ~ 40 nm connecting walls. Quantitative measurements of wax particles on the eye show that the nanostructures reduce particle contamination by more than ~ 96% compared to other areas of the cuticle. Altogether, our study is the first description of a predicted optimized grating geometry for anti-contamination in an arthropod. The findings serve as evidence of the high effectiveness of nanostructured surfaces for reducing contact area and thus adhesion forces between biological surfaces and contaminating particles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{LEHMANN2024104089,

title = {Spatio-temporal distribution and genetic background of elastic proteins inside the chitin/chitosan matrix of insects including their functional significance for locomotion},

author = {Fritz-Olaf Lehmann and Stanislav Gorb and Bernard Moussian},

url = {https://www.sciencedirect.com/science/article/pii/S0965174824000201},

doi = {https://doi.org/10.1016/j.ibmb.2024.104089},

issn = {0965-1748},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Insect Biochem Mol Biol},

volume = {168},

pages = {104089},

abstract = {In insects, cuticle proteins interact with chitin and chitosan of the exoskeleton forming crystalline, amorphic or composite material structures. The biochemical and mechanical composition of the structure defines the cuticle's physical properties and thus how the insect cuticle behaves under mechanical stress. The tissue-specific ratio between chitin and chitosan and its pattern of deacetylation are recognized and interpreted by cuticle proteins depending on their local position in the body. Despite previous research, the assembly of the cuticle composites in time and space including its functional impact is widely unexplored. This review is devoted to the genetics underlying the temporal and spatial distribution of elastic proteins and the potential function of elastic proteins in insects with a focus on Resilin in the fruit fly Drosophila. The potential impact and function of localized patches of elastic proteins is discussed for movements in leg joints, locomotion and damage resistance of the cuticle. We conclude that an interdisciplinary research approach serves as an integral example for the molecular mechanisms of generation and interpretation of the chitin/chitosan matrix, not only in Drosophila but also in other arthropod species, and might help to synthesize artificial material composites.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{STUDENT2024102661,

title = {Chitins and chitosans–A tale of discovery and disguise, of attachment and attainment},

author = {Mounashree Student and Margareta J. Hellmann and Stefan Cord-Landwehr and Bruno M. Moerschbacher},

url = {https://www.sciencedirect.com/science/article/pii/S1369526624001523},

doi = {https://doi.org/10.1016/j.pbi.2024.102661},

issn = {1369-5266},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Curr. Opin. Plant Biol},

volume = {82},

pages = {102661},

abstract = {Chitin polymers are an essential structural component of fungal cell walls, but host chitinases can weaken them, contributing to disease resistance in fungal pathogens. Chitin oligomers thus produced are immunogenic signal molecules eliciting additional disease resistance mechanisms. Fungi may counteract these, e.g. by partial deacetylation of chitin, converting it into chitosans, protecting the cell walls against chitinase attack, and inactivating elicitor active oligomers. This molecular stealth hypothesis for fungal pathogenicity has repeatedly been tested by mutating single or multiple chitin deacetylase genes, supporting the hypothesis but simultaneously suggesting additional roles for chitin deacetylation in virulence, such as surface attachment and sensing, host tissue penetration and colonization, as well as spore formation, stabilization, and germination. Interestingly, recent evidence suggests that host plants have evolved counter strategies by inhibiting fungal chitin deacetylases, lending further credibility to the suggested action of these enzymes as pathogenicity/virulence factors, and possibly offering leads toward novel functional fungicides.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Delbianco202411,

title = {Visualizing the structural diversity of glycoconjugates},

author = {Martina Delbianco and Yu Ogawa},

url = {https://www.nature.com/articles/s41589-023-01502-3},

doi = {10.1038/s41589-023-01502-3},

issn = {15524450},

year  = {2024},

date = {2024-01-01},

urldate = {2024-01-01},

journal = {Nat. Chem. Biol},

volume = {20},

pages = {11-12},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Direct observation of glycans bonded to proteins and lipids at the single-molecule level},

author = {K. Anggara and L. Srsan and T. Jaroentomeechai and X. Wu and S. Rauschenbach and Y. Narimatsu and H. Clausen and T. Ziegler and R. L. Miller and K. Kern },

url = {https://www.science.org/doi/10.1126/science.adh3856},

doi = {10.1126/science.adh3856},

issn = {0036-8075},

year  = {2023},

date = {2023-10-12},

urldate = {2023-10-12},

journal = {Science},

volume = {382},

pages = {219-223},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{10.7554/eLife.91079,

title = {The proteolysis of ZP proteins is essential to control cell membrane structure and integrity of developing tracheal tubes in textitDrosophila},

author = {Leonard Drees and Susi Schneider and Dietmar Riedel and Reinhard Schuh and Matthias Behr},

editor = {Elisabeth Knust and Claude Desplan},

url = {https://doi.org/10.7554/eLife.91079},

doi = {10.7554/eLife.91079},

issn = {2050-084X},

year  = {2023},

date = {2023-10-01},

urldate = {2023-10-01},

journal = {eLife},

volume = {12},

pages = {e91079},

publisher = {eLife Sciences Publications, Ltd},

abstract = {Membrane expansion integrates multiple forces to mediate precise tube growth and network formation. Defects lead to deformations, as found in diseases such as polycystic kidney diseases, aortic aneurysms, stenosis, and tortuosity. We identified a mechanism of sensing and responding to the membrane-driven expansion of tracheal tubes. The apical membrane is anchored to the apical extracellular matrix (aECM) and causes expansion forces that elongate the tracheal tubes. The aECM provides a mechanical tension that balances the resulting expansion forces, with Dumpy being an elastic molecule that modulates the mechanical stress on the matrix during tracheal tube expansion. We show in textitDrosophila that the zona pellucida (ZP) domain protein Piopio interacts and cooperates with the ZP protein Dumpy at tracheal cells. To resist shear stresses which arise during tube expansion, Piopio undergoes ectodomain shedding by the Matriptase homolog Notopleural, which releases Piopio-Dumpy-mediated linkages between membranes and extracellular matrix. Failure of this process leads to deformations of the apical membrane, tears the apical matrix, and impairs tubular network function. We also show conserved ectodomain shedding of the human TGFβ type III receptor by Notopleural and the human Matriptase, providing novel findings for in-depth analysis of diseases caused by cell and tube shape changes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{DalColle2023,

title = {Linker, loading, and reaction scale influence automated glycan assembly},

author = {Marlene C S Dal Colle and Manuel G Ricardo and Nives Hribernik and José Danglad-Flores and Peter H Seeberger and Martina Delbianco},

url = {https://www.beilstein-journals.org/bjoc/articles/19/77},

doi = {10.3762/bjoc.19.77},

issn = {1860-5397},

year  = {2023},

date = {2023-07-06},

urldate = {2023-07-06},

journal = {Beilstein J. Org. Chem.},

volume = {19},

pages = {1015-1020},

publisher = {Beilstein Institut},

abstract = {<jats:p>Automated glycan assembly (AGA) affords collections of well-defined glycans in a short amount of time. We systematically analyzed how parameters connected to the solid support affect the AGA outcome for three different glycan sequences. We showed that, while loading and reaction scale did not significantly influence the AGA outcome, the chemical nature of the linker dramatically altered the isolated yields. We identified that the major determinants of AGA yields are cleavage from the solid support and post-AGA purification steps.</jats:p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RN14428,

title = {Dextran sulfate sodium and uracil induce inflammatory effects and disrupt the chitinous peritrophic matrix in the midgut of Tribolium castaneum},

author = {A. C. Böhringer and L. Deters and A. G. Windfelder and H. Merzendorfer},

url = {https://www.ncbi.nlm.nih.gov/pubmed/37907139},

doi = {10.1016/j.ibmb.2023.104029},

issn = {0965-1748},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Insect Biochem Mol Biol},

volume = {163},

pages = {104029},

abstract = {Dextran sulfate sodium is used in inflammatory bowel disease (IBD) mice models to trigger chronic intestinal inflammation. In this study, we have analyzed DSS effects in the genetic model and pest beetle, Tribolium castaneum, which can be easily and cost-effectively cultivated and examined in very large quantities compensating for individual variations. We fed the larvae with DSS and uracil, which is known to induce the production of reactive oxygen species by activating DUOX, a member of the NADPH oxidase family. Both chemicals induced IBD-like phenotypes, including impaired growth and development, midgut thickening, epithelial swelling, and a loss of epithelial barrier function. RNAi mediated knockdown of DUOX expression enhanced the effects of DSS and uracil on mortality. Finally, we showed that both treatments result in an altered activity of the intestinal microbiome, similar as observed in IBD patients. Our findings suggest that both chemicals impair the epithelial barrier by increasing the permeability of the peritrophic matrix. The loss of the barrier function may facilitate the entry of midgut bacteria triggering innate immune responses that also affect the intestinal microbiome. As the observed effects resemble those induced by DSS treatment in mice, T. castaneum might be suitable high-throughput invertebrate model for IBD research and preclinical studies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RN5,

title = {High-throughput vibrational spectroscopy methods for determination of degree of acetylation for chitin and chitosan},

author = {H. U. Rehman and S. Cord-Landwehr and V. Shapaval and S. Dzurendova and A. Kohler and B. M. Moerschbacher and B. Zimmermann},

url = {https://www.ncbi.nlm.nih.gov/pubmed/36604090},

doi = {10.1016/j.carbpol.2022.120428},

issn = {0144-8617},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Carbohydr Polym},

volume = {302},

pages = {120428},

abstract = {The rising demand for chitin and chitosan in chemical, agro-food, and healthcare industries is creating a need for rapid and high-throughput analysis. The physicochemical properties of these biopolymers are greatly dependent on the degree of acetylation (DA). Conventional methods for DA determination, such as LC-MS and 1H NMR, are time-consuming when performed on many samples, and therefore efficient methods are needed. Here, high-throughput microplate-based FTIR and FT-Raman methods were compared with their manual counterparts. Partial least squares regression models were based on 30 samples of chitin and chitosan with reference DA values obtained by LC-MS and 1H NMR, and the models were validated on an independent test set of 16 samples. The overall predictive accuracy of the high-throughput methods was at the same level as the manual methods and the well-established LC-MS and 1H NMR methods. Therefore, high-throughput FTIR and FT-Raman DA determination methods have great potential to serve as fast and economical substitutes for traditional methods.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RN4,

title = {Unraveling the Impact of Acetylation Patterns in Chitosan Oligomers on Cu(2+) Ion Binding: Insights from DFT Calculations},

author = {R. Singh and J. Smiatek and B. M. Moerschbacher},

url = {https://www.ncbi.nlm.nih.gov/pubmed/37762095},

doi = {10.3390/ijms241813792},

issn = {1422-0067},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Int J Mol Sci},

volume = {24},

abstract = {Chitosans are partially acetylated polymers of glucosamine, structurally characterized by their degree of polymerization as well as their fraction and pattern of acetylation. These parameters strongly influence the physico-chemical properties and biological activities of chitosans, but structure-function relationships are only poorly understood. As an example, we here investigated the influence of acetylation on chitosan-copper complexation using density functional theory. We investigated the electronic structures of completely deacetylated and partially acetylated chitosan oligomers and their copper-bound complexes. Frontier molecular orbital theory revealed bonding orbitals for electrophiles and antibonding orbitals for nucleophiles in fully deacetylated glucosamine oligomers, while partially acetylated oligomers displayed bonding orbitals for both electrophiles and nucleophiles. Our calculations showed that the presence of an acetylated subunit in a chitosan oligomer affects the structural and the electronic properties of the oligomer by generating new intramolecular interactions with the free amino group of neighboring deacetylated subunits, thereby influencing its polarity. Furthermore, the band gap energy calculated from the fully and partially deacetylated oligomers indicates that the mobility of electrons in partially acetylated chitosan oligomers is higher than in fully deacetylated oligomers. In addition, fully deacetylated oligomers form more stable complexes with higher bond dissociation energies with copper than partially acetylated ones. Interestingly, in partially acetylated oligomers, the strength of copper binding was found to be dependent on the pattern of acetylation. Our study provides first insight into the influence of patterns of acetylation on the electronic and ion binding properties of chitosans. Depending on the intended application, the obtained results can serve as a guide for the selection of the optimal chitosan for a specific purpose.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RN6,

title = {Quantitative enzymatic-mass spectrometric analysis of the chitinous polymers in fungal cell walls},

author = {M. J. Urs and B. M. Moerschbacher and S. Cord-Landwehr},

url = {https://www.ncbi.nlm.nih.gov/pubmed/36436867},

doi = {10.1016/j.carbpol.2022.120304},

issn = {0144-8617},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Carbohydr Polym},

volume = {301},

pages = {120304},

abstract = {Chitin is an essential structural component of complex and dynamic fungal cell walls. It may be converted by partial or full deacetylation to yield chitosan. Here, we describe a method to quantify N-acetyl D-glucosamine (GlcNAc, A) and D-glucosamine (GlcN, D) units and, thus, total amount and average fraction of acetylation (x̅ FA) of the chitinous polymers by complete enzyme hydrolysis of the polymers followed by mass spectrometric analyses of the monomers. First, the native polymers were isotopically N-acetylated, then enzymatically hydrolyzed to A and R (2H3 N-acetyl-D-glucosamine – former D) monomers. Relative abundances of A and R units were used to calculate x̅ FA, and a double-isotopically labeled internal standard R* ([13C2,2H3] N-acetyl-D-glucosamine) monomer was used to calculate the absolute amounts of GlcNAc and GlcN units present in the fungal samples. The method was validated using known chitosan polymers and is suitable for both purified cell walls and whole mycelia.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Maia2023180,

title = {Chitin oligomers promote lymphoid innate and adaptive immune cell activation},

author = {Ana Maia and Yamel Cardona Gloria and Katharina Fuchs and Tzu-Hsuan Chang and Pujan Engels and Min Zhou and Timo Hinnenthal and Elisa Rusch and Cécile Gouttefangeas and Alexander N. R Weber},

url = {https://academic.oup.com/jleukbio/article/114/2/180/7131286},

doi = {10.1093/jleuko/qiad044},

issn = {0741-5400},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {J. Leukoc. Biol},

volume = {114},

pages = {180 – 186},

abstract = {Chitin is a highly abundant N-acetylglucosamine polysaccharide that has been linked to immune responses in the context of fungal infections and allergic asthma, especially to T helper 2 immune responses. Unfortunately, due to the frequent use of crude chitin preparations of unknown purity and degree of polymerization, there is still great uncertainty about how chitin activates different parts of the human immune system. We recently identified chitin oligomers of 6 N-acetylglucosamine units as the smallest immunologically active chitin motif and the innate immune receptor TLR2 as a primary chitin sensor on human and murine myeloid cells, but the response of further immune cells (e.g. lymphoid cells) to oligomeric chitin has not been investigated. Our analysis of primary human immune cells now shows that chitin oligomers activate immune responses of both innate and adaptive lymphocytes: notably, chitin oligomers activated natural killer cells but not B lymphocytes. Moreover, chitin oligomers induced maturation of dendritic cells and enabled potent CD8+ T-cell recall responses. Our results suggest that chitin oligomers not only trigger immediate innate responses in a limited range of myeloid cells but also exert critical activities across the entire human immune system. This highlights chitin oligomer immune activation as an interesting and broadly applicable potential target for both adjuvant development and therapeutic interference in chitin-mediated pathologies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1111/1744-7917.13115,

title = {Chitinase 6 is required for procuticle thickening and organ shape in Drosophila wing},

author = {Wei Dong and Justin Flaven-Pouchon and Ying-Hao Gao and Chen-Yang Song and Abeer El Wakil and Jian-Zhen Zhang and Bernard Moussian},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/1744-7917.13115},

doi = {https://doi.org/10.1111/1744-7917.13115},

issn = {1672-9609},

year  = {2023},

date = {2023-01-01},

urldate = {2023-01-01},

journal = {Insect Sci},

volume = {30},

pages = {268-278},

abstract = {Abstract The polysaccharide chitin is a major scaffolding molecule in the insect cuticle. In order to be functional, both chitin amounts and chitin organization have been shown to be important parameters. Despite great advances in the past decade, the molecular mechanisms of chitin synthesis and organization are not fully understood. Here, we have characterized the function of the Chitinase 6 (Cht6) in the formation of the wing, which is a simple flat cuticle organ, in the fruit fly Drosophila melanogaster. Reduction of Cht6 function by RNA interference during wing development does not affect chitin organization, but entails a thinner cuticle suggesting reduced chitin amounts. This phenotype is opposed to the one reported recently to be caused by reduction of Cht10 expression. Probably as a consequence, cuticle permeability to xenobiotics is enhanced in Cht6-less wings. We also observed massive deformation of these wings. In addition, the shape of the abdomen is markedly changed upon abdominal suppression of Cht6. Finally, we found that suppression of Cht6 transcript levels influences the expression of genes coding for enzymes of the chitin biosynthesis pathway. This finding indicates that wing epidermal cells respond to activity changes of Cht6 probably trying to adjust chitin amounts. Together, in a working model, we propose that Cht6-introduced modifications of chitin are needed for chitin synthesis to proceed correctly. Cuticle thickness, according to our hypothesis, is in turn required for correct organ or body part shape. The molecular mechanisms of this processes shall be characterized in the future.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{RN14341,

title = {Biotechnologically produced chitosans with nonrandom acetylation patterns differ from conventional chitosans in properties and activities},

author = {S. Sreekumar and J. Wattjes and A. Niehues and T. Mengoni and A. C. Mendes and E. R. Morris and F. M. Goycoolea and B. M. Moerschbacher},

doi = {10.1038/s41467-022-34483-3},

issn = {2041-1723},

year  = {2022},

date = {2022-12-01},

urldate = {2022-01-01},

journal = {Nat Commun},

volume = {13},

number = {1},

pages = {7125},

keywords = {},

pubstate = {published},

tppubtype = {article}

}