Molecular cloning, recombinant protein expression and structural characterization of a universal stress G4LZI3 protein from Schistosoma mansoni
Human schistosomiasis is a primary tropical disease caused by the larvae of a blood fluke parasite called schistosome. Different species of schistosomes are responsible for various types of schistosomiasis but most of the burden of the disease is attributed to the species Schistosoma mansoni. The outcome of S. mansoni infection includes damage to vital organs such as the intestine, spleen, bladder, lungs and liver. If left untreated it can also lead to weight loss and growth retardation in children, higher risk of anaemia, infertility, and increase susceptibility to HIV and in extreme cases, cancer. Till date, the frontline drug for the treatment of schistosomiasis is praziquantel which has various limitations and of late, drug resistance. The limitations of this first line drug has made it necessary for alternative interventions for combating the disease in terms of novel drugs and vaccines discovery and development, as well as the design of specific diagnostic tools for early diagnosis. The genome of S. mansoni has been predicted to encode different stress proteins including the Universal Stress Protein (USP). It has been previously hypothesized that the USP of schistosome parasites have shared protein sequence features which can be useful for inferring their biochemical and environmental regulation. Interestingly, proteins that have such shared features can be very useful targets for disease intervention. Universal stress proteins (USPs) act as natural biological defence mechanisms in living organisms. They are overexpressed in stress conditions and assist in overcoming stressors through various mechanisms. USPs has been predicted to play a role in host invasion by pathogens such as Mycobacterium, Salmonella and Klebsiella; thus may be useful in the treatment of various pathogenic diseases. The aim of this study is to characterize a novel Schistosoma mansoni universal stress protein G4LZI3, which has been hypothesized as a druggable target, as well as a vaccine candidate against the parasite in humans. Bioinformatics analysis of the G4LZI3 gene sequence was done to predict structural information about the protein which served as a guide towards the choice of conditions for further experimental procedure. These experimental procedures were used to determine the purity, the actual molecular weight, secondary structure element and thermostability of the protein. More so, the characterization of the expressed G4LZI3 protein reveals the secondary structural elements of the proteins and above all, a considerable amount of the recombinant protein could be expressed in bacteria and adequately purified. The results showed the possible amenability of the protein to structural determination either by heteronuclear NMR spectroscopy or X-ray crystallography which is vital towards the ultimate goal of developing a new alternative but efficient drug against schistosomiasis.
Human schistosomiasis --neglected tropical diseases --schistosomes --Schistosoma mansoni --praziquantel --Universal Stress Protein --recombinant protein expression --in-silico.
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