8k5h
Structure of the SARS-CoV-2 BA.1 spike with UT28-RDStructure of the SARS-CoV-2 BA.1 spike with UT28-RD
Structural highlights
FunctionSPIKE_SARS2 attaches the virion to the cell membrane by interacting with host receptor, initiating the infection (By similarity). Binding to human ACE2 receptor and internalization of the virus into the endosomes of the host cell induces conformational changes in the Spike glycoprotein (PubMed:32142651, PubMed:32075877, PubMed:32155444). Uses also human TMPRSS2 for priming in human lung cells which is an essential step for viral entry (PubMed:32142651). Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes.[HAMAP-Rule:MF_04099][1] [2] [3] mediates fusion of the virion and cellular membranes by acting as a class I viral fusion protein. Under the current model, the protein has at least three conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes.[HAMAP-Rule:MF_04099] Acts as a viral fusion peptide which is unmasked following S2 cleavage occurring upon virus endocytosis.[HAMAP-Rule:MF_04099] Publication Abstract from PubMedSARS-CoV-2 rapidly mutates and acquires resistance to neutralizing antibodies. We report an in-silico-designed antibody that restores the neutralizing activity of a neutralizing antibody. Our previously generated antibody, UT28K, exhibited broad neutralizing activity against mutant variants; however, its efficacy against Omicron BA.1 was compromised by the mutation. Using previously determined structural information, we designed a modified-UT28K (V(H) T28R/N57D), UT28K-RD targeting the mutation site. In vitro and in vivo experiments demonstrated the efficacy of UT28K-RD in neutralizing Omicron BA.1. Although the experimentally determined structure partially differed from the predicted model, our study serves as a successful case of antibody design, wherein the predicted amino acid substitution enhanced the recognition of the previously elusive Omicron BA.1. We anticipate that numerous similar cases will be reported, showcasing the potential of this approach for improving protein-protein interactions. Our findings will contribute to the development of novel therapeutic strategies for highly mutable viruses, such as SARS-CoV-2. Rational in silico design identifies two mutations that restore UT28K SARS-CoV-2 monoclonal antibody activity against Omicron BA.1.,Ozawa T, Ikeda Y, Chen L, Suzuki R, Hoshino A, Noguchi A, Kita S, Anraku Y, Igarashi E, Saga Y, Inasaki N, Taminishi S, Sasaki J, Kirita Y, Fukuhara H, Maenaka K, Hashiguchi T, Fukuhara T, Hirabayashi K, Tani H, Kishi H, Niimi H Structure. 2024 Mar 7;32(3):263-272.e7. doi: 10.1016/j.str.2023.12.013. Epub 2024 , Jan 15. PMID:38228146[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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