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Basic Characteristics of Mutations
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Mutation Site
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F486V |
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Mutation Site Sentence
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In comparison to BA.1, 5/6 mutations within the NTD and 5/17 in the RBD are unique to BA.4/5; L452R and F486V within the BA.4/5 RBD are believed to be responsible for its ability to evade immunity due to vaccination and/or previous infection by Omicron BA.1. |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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RBD |
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Standardized Encoding Gene
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S
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Genotype/Subtype
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BA.4/BA.5 |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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COVID-19
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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- |
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Location
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- |
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Literature Information
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PMID
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37200378
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Title
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Enhanced stability of the SARS CoV-2 spike glycoprotein following modification of an alanine cavity in the protein core
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Author
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Poumbourios P,Langer C,Boo I,Zakir T,Center RJ,Akerman A,Milogiannakis V,Aggarwal A,Johnstone BA,Ha J,Coulibaly F,Turville SG,Drummer HE
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Journal
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PLoS pathogens
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Journal Info
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2023 May 18;19(5):e1010981
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Abstract
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The spike (S) glycoprotein of SARS CoV-2 is the target of neutralizing antibodies (NAbs) that are crucial for vaccine effectiveness. The S1 subunit binds ACE2 while the S2 subunit mediates virus-cell membrane fusion. S2 is a class I fusion glycoprotein subunit and contains a central coiled coil that acts as a scaffold for the conformational changes associated with fusion function. The coiled coil of S2 is unusual in that the 3-4 repeat of inward-facing positions are mostly occupied by polar residues that mediate few inter-helical contacts in the prefusion trimer. We examined how insertion of bulkier hydrophobic residues (Val, Leu, Ile, Phe) to fill a cavity next to Ala1016 and Ala1020 in the 3-4 repeat affects the stability and antigenicity of S trimers. Substitution of Ala1016 with bulkier hydrophobic residues in the context of a prefusion-stabilized S trimer, S2P-FHA, was associated with increased thermal stability. S glycoprotein membrane fusion function was retained with Ala1016/Ala1020 cavity-filling mutations associated with improved recombinant S2P-FHA thermostability, however 2 mutants, A1016L and A1016V/A1020I, lacked ability to mediate entry of S-HIV-1 pseudoparticles into 293-ACE2 cells. When assessed as immunogens, two thermostable S2P-FHA mutants derived from the ancestral isolate, A1016L (16L) and A1016V/A1020I (VI) elicited neutralizing antibody with 50%-inhibitory dilutions (ID50s) in the range 2,700-5,110 for ancestral and Delta-derived viruses, and 210-1,744 for Omicron BA.1. The antigens elicited antibody specificities directed to the receptor-binding domain (RBD), N-terminal domain (NTD), fusion peptide and stem region of S2. The VI mutation enabled the production of intrinsically stable Omicron BA.1 and Omicron BA.4/5 S2P-FHA-like ectodomain oligomers in the absence of an external trimerization motif (T4 foldon), thus representing an alternative approach for stabilizing oligomeric S glycoprotein vaccines.
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Sequence Data
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-
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