Cell walls of seagrasses from the Baltic, the Mediterranean, the Red sea and the Indian Ocean– a new source of galactans for interaction with human galectins

• Applicant: Professorin Dr. Birgit Classen
• Subject Area: Pharmacy
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 456721142

The project will combine basic research on cell wall composition of seagrasses (focus on galactans) with applied aspects on possible applications of these galactans as model substances for therapeutic galectin inhibitors.The first part of this proposal aims at cell wall characterization by sequential precipitations and analytical characterization of the different fractions (water-soluble fraction, pectic fraction, hemicelluloses) and isolation and structural characterization of arabinogalactan-proteins (AGPs) from eight seagrass species from different habitats (Baltic Sea, Mediterranean Sea, Red Sea, Indian Ocean), which is of evolutionary (adaption to the marine environment) and technological (cell walls of seagrasses as source of environmentally friendly products) interest.In the second part, these AGPs will be used together with other plant AGPs as source for production of galactans of different structure and reduced molecular mass. These galactans will be tested for their potential to interact with human galectins -1, -3, -7 and -9 which execute key roles in immune function and tumor progression. To evaluate the influence of sulfate groups, part of the galactans will be chemically sulfated. Binding capacities will be quantified using different test systems (ELISA, biolayer interferometry, isothermal titration calorimetry). Furthermore, the impact of the galactans on processes of cancer progression such as cell migration, cell adhesion and cell growth of different pancreatic ductal adenocarcinoma cell lines in comparison to benign and premalignant pancreatic ductal epithelial cells will be investigated. The results will broaden the knowledge on interactions between human galectins and plant glycans and contribute to understanding of different sugar-binding specificities of galectins. Expertise on new glycan structures binding to galectins is a step forward to development of therapeutic galectin inhibitors.

• DFG Programme: Research Grants