Expression and characterization of proteins for drug and food applications

Sivan Gelley; PhD Seminar - Prof. Ayelet Fishman Lab

Over the last few decades, recombinant proteins have been produced for diverse applications. Antibodies are manufactured for immunotherapy and diagnostic devices. A variety of enzymes are used to treat genetic disorders; while others are developed for industrial use like biodiesel production. Recently, recombinant proteins are also being developed for food applications, some of which have recently been recognized as safe. Two recombinant proteins were expressed and characterized in this research in various expression systems (bacteria, yeast, insect and mammalian).
The goal of the first project was to develop an enzymatic treatment to slowdown Alzheimer’s disease progression. An early characteristic of Alzheimer’s disease is formation of plaques, which are neurotoxic aggregates of Amyloid ß peptides. Cleavage within the Amyloid ß peptide sequence, may prevent formation of plaques and will therefore slowdown disease progression. To this end, a specific protease was expressed in a variety of expression systems and the purified enzyme was characterized.
The goal of the second project was to uncouple potato patatin production from agriculture. In recent years there has been a growing interest in alternatives for animal proteins, to feed the world’s growing population. Protein alternatives are divided to three categories: plant-based, fermentation and cultured meat. Of the plant-based proteins, potato proteins provide an interesting option due to their nutritional value and high functionality. However, agriculture dependence, cultivar variability and low yields may make their production challenging. Here, two potato patatin isoforms were expressed in Pichia pastoris. Biochemical and physical characterization of the purified recombinant proteins compared with commercial patatin, revealed that the purified yeast-derived patatins were comparable, and in some cases even superior, to potato isolated patatins.