Serpin from Eudiplozoon nipponicum

The properties of proteins (e.g. functions) of the members from the family Monogenea are among the less investigated in whole phylum Platyhelminthes. We chose Eudiplozoon nipponicum as our experimental organism to address this issue and complete the mosaic of its functional proteins equipment. E. nipponicum (family Diplozoidae, Polyopisthocotylea) is hematophagous ectoparasite which lives on the gills of common carp (Cyprinus carpio). The main aim of our current work is to understand the regulation of peptidase activity related to many physiological processes. Among the key regulatory factors could be included the peptidase inhibitors, such as serpins - serine peptidase inhibitors. These functional proteins are generally known as important regulators of the coagulation cascade, complement, fibrinolysis, angiogenesis, inflammation etc. The inhibition, mediated by serpins, is typically irreversible, comprising conformational changes in serpin molecule leading to distortion of peptidase tertiary structure. Except the inhibition, some of them may have other functions like e.g. protein transporters or chaperones and they are relatively abundant also in secretions, body lysates and genomes/transcriptomes of helminths. We identified serpin gene/protein in transcriptome of E. nipponicum and investigated properties of its recombinant form – molecular and biochemical characterization was performed. The tertiary structure was predicted, antigenic properties evaluated and inhibitory effect measured.