Missense mutations in spike protein of SARS-CoV-2 delta variant contribute to the alteration in viral structure and interaction with hACE2 receptor.

Introduction: Many of the global pandemics threaten human existence over the decades among which coronavirus disease (COVID-19) is the newest exposure circulating worldwide. The RNA encoded severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is referred as the pivotal agent of this deadly disease that induces respiratory tract infection by interacting host ACE2 receptor with its spike glycoprotein. Rapidly evolving nature of this virus modified into new variants helps in perpetrating immune escape and protection against host defense mechanism. Consequently, a new isolate, delta variant originated from India is spreading perilously at a higher infection rate.

Methods: In this study, we focused to understand the conformational and functional significance of the missense mutations found in the spike glycoprotein of SARS-CoV-2 delta variant performing different computational analysis.

Results: From physiochemical analysis, we found that the acidic isoelectric point of the virus elevated to basic pH level due to the mutations. The targeted mutations were also found to change the interactive bonding pattern and conformational stability analyzed by the molecular dynamic's simulation. The molecular docking study also revealed that L452R and T478K mutations found in the RBD domain of delta variant spike protein contributed to alter interaction with the host ACE2 receptor.

Conclusions: Overall, this study provided insightful evidence to understand the morphological and attributive impact of the mutations on SARS-CoV-2 delta variant.