Comparative physicochemical and evolutionary study of SARS-CoV-2 and SARS with special reference to salt bridge and their microenvironment: A plausible explanation for divergency, stability and severity of SARS-CoV-2

Abstract

The occurrence of concentrated pneumonia cases in Wuhan city, Hubei province of China was first reported on December 30, 2019. Currently, it is known as COVID 19 and now it is a nightmare for the whole world. SARS CoV first reported in 2002, but not spread worldwide. After 18 years, in 2020 it reappears and spread worldwide as SARS-CoV-2 (COVID 19), the most dangerous virus creating disease in the world. Is it possible to create a favorable evolution within this short time? If possible, then what are those properties that are changed in SARS-CoV-2 to make it undefeated? What are the basic differences between SARS-CoV-2 and SARS? This study will find all those queries. Here, all protein sequences of SARS-CoV-2 and SARS are retrieved from the database to check their physicochemical, evolutionary and structural properties. Results showed that, charged residues are playing a key role in SARS-CoV-2 evolution. SARS-CoV-2 increases its polarity by the help of charged residues, not by the polar residues. Their divergence is also strictly restricted. Induction of salt bridges with their high energies makes it very stable in any extreme conditions. Microenvironment residues also play a very crucial role in its stability. Mostly residues are favorable and contribute high energies. These microenvironment residues help in protein engineering to reduce its stability and make them week. This comparative study will help to understand the evolution from SARS to SARS-CoV-2.