Alexandra Machado Ferreira Castilho

Research Focus

Plant Molecular Farming (PMF) refers to the production of valuable proteins through the use of plant biotechnology. Despite great successes, the expression of recombinant proteins in plants still has some bottlenecks. Protein glycosylation is one of the most important post-translational modifications, and while N-glycan synthesis in the endoplasmic reticulum (ER) is relatively well conserved in eukaryotes, the processing of N-glycans in the Golgi apparatus is kingdom specific and there is great variation in the glycosylation pathway of plants and animals hinders the production of relevant glycoproteins in plants. Glycodesign is a powerful tool for optimizing the glycoprofiles of therapeutic glycoproteins for their effectiveness. Our research aims to develop, optimize and evaluate methods to tailor the structures of glycans to relevant recombinant proteins produced in Nicotiana benthamiana, currently the most suitable host for use in PMF. We use a variety of approaches to genetically manipulate glycosyltransferases (GTs), glycohydrolases (GH), nucleotide sugar converting enzymes, and transporters to control glycan biosynthesis in N. benthamiana. The results of our research can be used to identify individual structures fundamental to glycan-mediated processes and facilitate the development of “biobetter” proteins with tailored glycan profiles that enhance their activities.