Immuno-informatics Characterization SARS-CoV-2 Spike Glycoprotein for Prioritization of Epitope based Multivalent Peptide Vaccine

Saba Ismail; Sajjad Ahmad; Syed Sikander Azam

Further, disulfide engineering of the MEPVC was performed in order to optimize molecular interactions and confer considerable stability by attaining precise geometric conformation [89, 90] . Eight pairs of residues were selected to be replaced with cysteine amino acid. These pairs are: Gln7-Ala19 (χ3 angle,+118, energy value, 4.20 kcal/mol), Cys18-Leu21 (χ3 angle,+84.35, energy value, 3.69 kcal/mol), Lys44-Ala47 (χ3 angle,+74.17, energy value,5.59 kcal/mol), Arg57-Ala61 (χ3 angle,+122.71 , energy value,6.14 kcal/mol), Ala72-Ala85 (χ3 angle,-62.92, energy value,4.40 kcal/mol), Ala73-Ala82 (χ3 angle, , energy value, kcal/mol), Leu92-Glu95 (χ3 angle, -102.37 , energy value, 3.86 kcal/mol), and Phe111-Pro117 (χ3 angle,-96.20 , energy value,4.14 kcal/mol). These residues have either higher energy level i.e. > 2 kcal/mol and χ3 angle out of range (< −87 and > + 97) were selected on purpose to make them stable. The original and disulfide mutant MEPVC structures are shown in Fig.6 . The primary purpose of in silico cloning of the MEPVC was guide molecular biologist and genetic engineers about the possible cloning sites and predicted level of expression in a specific expression system for instance here in this study we used E. coli K12 system. Prior to cloning, reverse translation of the MEPVC sequence was conducted to have an optimized codon usage as per E. coli K12 to yield its max expression. The CAI value of the improved MEPVC sequence is 1 indicating ideal expression of the vaccine [91] . The GC content whereas is 53.2 % nearly to the E. coli K12 and range within the optimum ranged between 30 % and 70%. The cloned MEPVC is shown in Fig.7. . author/funder. All rights reserved. No reuse allowed without permission.