Screening Of Inhibitors Of Taenia Solium Glycogen Synthase Kinase-3β

Taenia solium is a zoonotic parasite.Humans are the only definitive hosts of the adult Taenia solium,and can be used as the intermediate hosts;pigs are also the intermediate hosts.When people eating raw or undercooked pork that contain cysticercus,cysticercus can develop into an adult tapeworm in the small intestine of humans,and exclude gravid proglottids and eggs.The clinical symptoms of taeniasis are mild,some patients have indigestion,abdominal pain,weight loss and other symptoms.It is the most common symptom that proglottids are found in patients’ faeces.Cysticercosis is one of serious parasitic diseases that harm to human health,and is mainly caused by drinking waters or eating foods that contaminated by eggs.Cysticercus can lodge in muscle,skin,eyes and central nervous system(neurocysticercosis,NCC),the main NCC symptoms include severe headache,seizures,blindness,hydrocephalus,meningitis,even causing death.An estimated 2.5 million people are infected with Taenia solium,and there are about 50000 deaths annually due to NCC.The World Health Organization(WHO)designated taeniasis/cysticercosis is one of the 17 neglected tropical diseases in 2010.Glycogen synthase kinase-3(GSK-3)is a serine / threonine protein kinase,GSK-3 has two isoforms: GSK-3 alpha and GSK-3 beta.GSK-3 beta is not only widely involved in physiological processes(cell growth,proliferation,differentiation and apoptosis),but also closely related to the abnormal signal pathway(type 2 diabetes,bipolar disorder,cancer,Alzheimer’s disease).At present,GSK-3 beta as a drug target has been reported in the research of anti-parasitic drugs,such as Trypanosoma brucellum,Plasmodium falciparum,Leishmania,and so on.It has become one of the most potential and important drug targets for many diseases,and one of the potential targets of anti-parasitic drugs.Computer aided drug screening is a very important tool in the field of drug discovery,which can accelerate the speed of drug development and save the cost of drug research and development.The combination of the computer virtual screening method and the biological experimental method can form a good complement,which provides a guarantee for screening reliable ligand molecules.In this paper,we first virtual screening of the compounds by using Ts GSK-3 beta(receptor)and two compound libraries(NCI and ZNIC);secondly,the screened compounds were tested.The Specific contents are as follows:(1)The full-length nucleotide sequence of Ts GSK-3β is determined by using 3’-and 5’-RACE method,which has been deposited to Gen Bank and the accession number is KY550711.The Ts GSK-3β tertiary structure was generated,and the crystal structure of Hs GSK-3β(PDB: 1UV5)was chosen as the template protein for computer-aided molecular modeling.The 3D molecular similarity method was used to establish a set of small molecule ligands for ZNIC and NCI compound libraries,and the high precision semi flexible docking with the Ts GSK-3 beta receptor was performed.Finally,14 small molecular compounds were retained.(2)For the detection of molecular activity,the Ts GSK-3 beta protein was expressed in mammalian cells,and purified by affinity chromatography.The affinity of 14 small molecules to Ts GSK-3 beta and Hs GSK-3 beta was detected by surface plasmon resonance imaging(SPRI)technology.Finally,the 3 small molecule compounds(the number 3,5,8)that have a high affinity for Ts GSK-3 beta but not bond to Hs GSK-3 beta were selected,which are potential lead compounds.(3)Three small molecules that only bond to Ts GSK-3 beta are selected by virtual screening and SPRI technology,3 molecular compounds were studied for antiparasitic effects in vitro,two Ts GSK-3 beta inhibitors(No.3 and No.5)are potential lead compounds,which have certain efficacy in the treatment of Echinococcus multilocularis and No.8 was poor in solubility.In this study,our works laid the foundation for further research anti-tapeworm drugs,and it also provides new ideas for the research of other disease-resistant drugs.