Shedding light on biochemical features and potential immunogenic epitopes of Neospora caninum SAG1: In silico study

• Published in: Informatics in medicine unlocked 2021, Vol.27, p.100785, Article 100785
• Main Authors: Shams, Morteza, Khazaei, Sasan, Nazari, Naser, Majidiani, Hamidreza, Kordi, Bahareh
• Format: Article
• Language: English
• Subjects: Bioinformatics; Immunogenic epitopes; N. caninum; SAG1
• ISSN: 2352-9148; 2352-9148
• DOI: 10.1016/j.imu.2021.100785

Vaccination is the only feasible way for appropriate prevention of Neospora caninum infection. The present in silico study was done to evaluate the physico-chemical properties and determine immunogenic epitopes of N. caninum SAG1 protein as a possible vaccine candidate. Web-based tools were used to predict physico-chemical properties, antigenicity, allergenicity, solubility, post-translational modification (PTM) sites, transmembrane domains and signal peptide, secondary and tertiary structures as well as intrinsically disordered regions, followed by identification and screening of potential linear and conformational B-cell epitopes and those peptides having affinity to bind mouse major histocompatibility complex (MHC) and cytotoxic T lymphocyte (CTL). The protein was stable in a test tube, had 319 residues with a molecular weight of 33.07 kDa, representing aliphatic index of 76.68 (thermotolerant) and GRAVY score of 0.031 (hydrophobic). There were 42 PTM sites and an N-terminally-located signal peptide in the sequence. Secondary structure comprised mostly by random coils, followed by strands and helices. Ramachandran plot of the refined model showed 71.7%, 24.9%, 3.0% and 0.4% residues in the favored, additional allowed, generously allowed and disallowed regions, correspondingly. Additionally, various potential B-cell (linear and conformational), CTL and MHC-binding epitopes were predicted for N. caninum SAG1. The findings of the present in silico study are a premise for vaccination strategies against neosporosis.