SPIKE GLYCOPROTEIN MUTATIONS AT POSITIONS 452 & 486
Position 452 is located in the receptor binding motif in the RBD, the amino acid substitution L452M will increase the size of the side chain of the spike protein RBD region.6 Position 486 is pivotal in binding RBD to hACE2.7 Positions 452 and 486 of the SARS-CoV-2 sublineages of omicron have been reported to be mutation prone; the mutational analysis of XBC.1 identified a unique mutation, L452M when compared with seventeen SARS-CoV-2 sublineages of omicron. In particular, BA.5, CH.1.1, BA.4.6, BA.4, BQ.1.1, BQ.1, BF.7 and XAY.2 were found to have L452R mutation (Figure).
Additionally, a rare mutation, F486P was found in the variants XBB.1.5, XAY.2, and XBC.1. This mutation is caused by two nucleotide polymorphisms in a single codon in comparison to the wild-type Wuhan strain. CH.1.1, XBB, BA.2.75.2, XBB.1 and XBB.2 have F486S mutation; and BQ.1.1, BA.4.6, BQ.1, BF.7, BA.5, and BA.4 have F486V mutation.