Determination of Certain Immunological and Physicochemical Features of Pneumococcal Surface Protein A (PspA): In-silico Cloning of pspA

Objective: Pneumococcal surface protein A (PspA) is present in almost all strains of pneumococci and is highly immunogenic, stimulating the production of antibodies. It has a role in pneumococcal pathogenicity. This study aimed to determine some immunological and physicochemical properties of PspA using bioinformatics software. Also, an in silico study was applied to clone the pspA gene by ligating it into pCRII-TOPO and transferring it into E. coli Bl21.Materials and Methods: PspA (WP_368082102) and pspA (U89711) were extracted from NCBI. The programs performed in this work included: PSIPRED, MemBrain 3.1, XtalPred, FUpred, CoCoPRED, Signal-CF, EzyPred, OSML, C-IMMSIM, Geneious Prime, AMUSER 1.0, PyMOL, and CCP4MG. Results: PspA has 5 distinct boundary domains and 8 coiled-coil domain (CCD) network. FU-score values were found between residues 430-540 and 780-810. Antibody production (IgM+ IgG) commences on the fifth day of infection. The IFN-g reached high peak concentration and stabilized between days 12 and 17, followed by IL-23. The pspA was successfully ligated in pCRII-TOPO and cloned in E. coli BL21. Conclusions: The PspA lacks enzymatic activity, which may pave the path for future research into developing an anti-PspA vaccination or discovering a medication that may negate its effects.