COVID-19 is a disease caused by severe acute respiratory syndrome coronavirus 2 or SARS-CoV-2 pathogen. Although a number of new vaccines are available to combat this threat, a high prevalence of novel mutant viral variants is observed in all world regions affected by this infection. Among viral proteomes, the highly glycosylated spike protein (Sprot) of SARS-CoV-2 has received the most attention due to its interaction with the host receptor ACE2. To understand the mechanisms of viral variant infectivity and the interaction of the RBD of Sprot with the host ACE2, we performed a large-scale mutagenesis study of the RBD-ACE2 interface by performing 1780 point mutations in silico and identifying the ambiguous stabilisation of the interface by the most common point mutations described in the literature. Furthermore, we pinpointed the N501Y mutation at the RBD of Sprot as profoundly affecting complex formation and confirmed greater stability of the N501Y mutant compared to wild-type (WT) viral S protein by molecular dynamics experiments. These findings could be important for the study and design of upcoming vaccines, PPI inhibitor molecules, and therapeutic antibodies or antibody mimics.