In-silicoAnalysis of SARS-Cov2 Spike Proteins of Different Field Variants

ABSTRACT Background Coronaviruses belong to the group of RNA family of viruses which trigger diseases in birds, humans, and mammals, which can cause respiratory tract infections. The COVID-19 pandemic has badly affected every part of the world, and the situation in the world is getting worse with the emergence of novel variants. Our study aims to explore the genome of SARS-,CoV2 followed by in silico analysis of its proteins. Methods Different nucleotide and protein variants of SARS-Cov2 were retrieved from NCBI. Contigs & consensus sequences were developed to identify variations in these variants by using SnapGene. Data of variants that significantly differ from each other was run through Predict Protein software to understand changes produced in protein structure The SOPMA web server was used to predict the secondary structure of proteins. Tertiary structure details of selected proteins were analyzed using the online web server SWISS-MODEL. Findings Sequencing results shows numerous single nucleotide polymorphisms in surface glycoprotein, nucleocapsid, ORF1a, and ORF1ab polyprotein. While envelope, membrane, ORF3a, ORF6, ORF7a, ORF8, and ORF10 genes have no or few SNPs. Contigs were mto identifyn of variations in Alpha & Delta Variant of SARs-CoV-2 with reference strain (Wuhan). The secondary structures of SARs-CoV-2 proteins were predicted by using sopma software & were further compared with reference strain of SARS-CoV-2 (Wuhan) proteins. The tertiary structure details of only spike proteins were analyzed through the SWISS-MODEL and Ramachandran plot. By Swiss-model, a comparison of the tertiary structure model of SARS-COV-2 spike protein of Alpha & Delta Variant was made with reference strain (Wuhan). Alpha & Delta Variant of SARs-CoV-2 isolates submitted in GISAID from Pakistan with changes in structural and nonstructural proteins were compared with reference strain & 3D structure mapping of spike glycoprotein and mutations in amino acid were seen. Conclusion The surprising increased rate of SARS-CoV-2 transmission has forced numerous countries to impose a total lockdown due to an unusual occurrence. In this research, we employed in silico computational tools to analyze SARS-CoV-2 genomes worldwide to detect vital variations in structural proteins and dynamic changes in all SARS-CoV-2 proteins, mainly spike proteins, produced due to many mutations. Our analysis revealed substantial differences in functional, immunological, physicochemical, & structural variations in SARS-CoV-2 isolates. However real impact of these SNPs can only be determined further by experiments. Our results can aid in vivo and in vitro experiments in the future.