| Summary: | Proteases are involved in many physiological processes and their dysregulation is associated with various pathologies. Protease activity is effectively controlled by natural inhibitors. This PhD thesis is focused on the inhibitors of aspartic and serine proteases of animal and plant origin and provides the identification, biochemical characterization and structural description of their inhibition mechanisms. Plant Kunitz inhibitors are produced as defensive proteins, and they are able to block activities of a broad spectrum of proteases. In this thesis, the digestive proteolytic system of the Colorado potato beetle, a herbivore pest of potato plants, was described with the help of functional proteomics. It was shown that aspartic and serine proteases from this herbivore are effectively blocked by two potato Kunitz inhibitors (namely PCDI, PSPI). Using structural analysis, novel types of reactive centers were identified on PCDI and PSPI molecules for the inhibition of aspartic protease cathepsin D and the serine proteases trypsin and chymotrypsin. The analysis of the reactive center on a PCDI with the crystal structure of digestive cathepsin D from the Colorado potato beetle explained the mechanism of their interaction. Sphingolipids were identified as the first endogenous inhibitors of human...
|
|---|
