Towards structural characterization of SmSP2 protease from parasitic blood fluke Schistosoma mansoni


Adrian Leontovyč1, Lenka Ulrychová1, Martin Horn1, Michael Mareš1, Jan Dvořák2

1Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 16610 Prague, Czech Republic

2School of Biological Sciences, Medical Biology Centre (MBC), Queen's University of Belfast, Belfast BT9 7BL, Northern Ireland, UK


Schistosomiasis is a parasitic disease caused by several blood flukes of the genus Schistosoma. It is considered the second most important parasitic infection after malaria with more than 200 million people infected worldwide and many more at risk. Treatment relies on a single drug – praziquantel. Hence, there is a pressing need to develop additional therapeutics. Proteolytic system of schistosomes is a promising target for the development of new antischistosomal drugs. In our research we focused on newly discovered trypsin-like protease SmSP2 from S. mansoni, predominant serine protease in schistosmula and adults. Recombinant SmSP2 was expressed in the P. pastoris expression system and purified using chromatographic methods. Polyclonal antibodies against SmSP2 were produced and used for immunolocalization experiments. Substrate cleavage specificity and inhibitor sensitivity were identified and explained using 3D homology model of SmSP2. We demonstrated that SmSP2 is capable of activate plasminogen to plasmin and release bradykinin from kininogen, therefore it could serve schistosomes as anticoagulant and vasodilatation agent, respectively. We prepared sufficient amount of recombinant SmSP2 for high-throughput crystallization screening, which is currently in progress. 3D structure model of SmSP2 will be employed for rational designing of specific inhibitors as potential drugs against schistosomiasis.