Host Cell Glycocalyx Remodeling Reveals SARS-Cov-2 Spike Protein Glycomic Binding Sites
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: 
Carlito B. Lebrilla
PROVIDER: MSV000088722 | MassIVE | Sat Jan 22 16:08:00 GMT 2022
REPOSITORIES: MassIVE
Similar Datasets
Project description:Glycans on the host cell membrane and viral proteins play critical roles in pathogenesis. Highly glycosylated epithelial cells represent the primary boundary separating embedded host tissues from pathogens within the respiratory and intestinal tracts. SARS-CoV-2, the causative agent for the COVID-19 pandemic, reaches into the respiratory tract. We found purified human milk oligosaccharides (HMOs) inhibited the viral binding on cells. Spike (S) protein receptor binding domain (RBD) binding to host cells were partly blocked by co-incubation with exogenous HMOs, most by 2-6-sialyl-lactose (6'SL), supporting the notion that HMOs can function as decoys in defense against SARS-Cov2. To investigate the effect of host cell glycocalyx on viral adherence, we metabolically modified and confirmed with glycomic methods the cell surface glycome to enrich specific N-glycan types including those containing sialic acids, fucose, mannose, and terminal galactose. Additionally, Immunofluorescence studies demonstrated that the S protein preferentially binds to terminal sialic acids with α-(2,6)-linkages. Furthermore, site-specific glycosylation of S protein RBD and its human receptor ACE2 were characterized using LC-MS/MS. We then performed molecular dynamics calculations on the interaction complex to further explore the interactive complex between ACE2 and the S protein. The results showed that hydrogen bonds mediated the interactions between ACE2 glycans and S protein with desialylated glycans forming significantly fewer hydrogen bonds. These results supported a mechanism where the virus binds initially to glycans on host cells preferring α-(2,6)-sialic acids and finds ACE2 and with the proper orientation infects the cell.
| S-EPMC8964299 | biostudies-literature
Project description:The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in millions of infections and deaths globally. Although vaccination campaigns are mitigating the pandemic, emerging viral variants continue to pose challenges. The spike (S) protein of SARS-CoV-2 plays a critical role in viral entry by binding to the angiotensin-converting enzyme 2 (ACE2) receptor, making both proteins essential targets for therapeutic and vaccine development. Glycosylation of these proteins influences their structure and function, underscoring the need for detailed site-specific glycoproteomic analysis.
In this study, we characterized the N- or O-glycosylation profiles of recombinant receptor-binding domain (RBD) of spike protein and ACE2 proteins expressed from HEK293 cells, as well as S2 subunit of spike protein expressed in plants cells. Using a high-resolution Orbitrap Eclipse Tribrid mass spectrometer integrated with the Ultimate 3000 RSLCnano and IQ-GPA (Identification and Quantification of GlycoProteome Analyzer), 148 N- and 28 O-glycopeptides from RBD, 71 N-glycopeptides from the S2 subunit, and 139 N-glycopeptides from ACE2 were characterized.
Additionally, we report novel post-translational modifications (PTMs) in RBD glycopeptides, including mannose-6-phosphate (M6P) and GlcNAc-1-phosphate-6-O-mannose of N-glycan, and O-acetylation of O-glycan, identified for the first time. These findings provide valuable insights into the glycosylation patterns that influence protein function and immunogenicity, offering new perspectives for the development of vaccines and antibody-based therapies against COVID-19.
2024-11-13 | MSV000096403 | MassIVE
Project description:The spike glycoprotein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mediates binding to the ACE2 receptor and subsequent membrane fusion. It exists in a range of conformations, including a closed state unable to bind the ACE2 receptor, and an open state that does so but displays more exposed antigenic surface. Spikes of variants of concern (VOCs) acquired amino acid changes linked to different opening probabilities, increased SARS-CoV-2 virulence and immune evasion. Here, using hydrogen-deuterium exchange mass spectrometry (HDX-MS), we analyzed the spike of the original Wuhan isolate, G614 mutant, spike of alpha, beta, delta and omicron VOCs and the isolated ancestral receptor binding domain (RBD) - in apo state and in complex with the ACE2 receptor. We identified changes in spike dynamics that we associated with the transition from closed to open conformation, to ACE2 binding, and to specific mutations in VOCs. We show that the RBD-associated subdomain plays a role in spike opening, whereas the NTD acts as a hotspot of conformational divergence of VOC spikes driving immune evasion. Alpha, beta and delta spikes assume predominantly open conformations and a strong ACE2 binding increases the dynamics of their core helices, priming spikes for fusion. Conversely, substitutions in omicron spike lead to predominantly binding-incompetent closed conformations, presumably enabling it to escape antibodies. At the same time, its core helices show characteristics of being pre-primed for fusion even in the absence of ACE2. These data inform on SARS-CoV-2 evolution and omicron variant emergence.
2023-03-15 | PXD039760 | Pride
Project description:The continuous evolution of SARS-CoV-2 poses global health challenges. A safe, rapid, and versatile method for assessing functions of Spike protein mutations in ACE2 receptor binding and immune evasion would be highly valuable. To address this, we engineered a transcription- and replication-competent virus-like particle (trVLP) derived from the Sindbis virus, pseudotyped with the SARS-CoV-2 receptor binding domain (RBD). This trVLP exclusively propagates in BHK-21 cell engineered to express both RNA replicase and human ACE2, providing a controllable, safe model of SARS-CoV-2 RBD-ACE2 interaction mediated virus entry. The system enables characterization of RBD interactions with ACE2 from various mammalian hosts, demonstrating its utility for studying host-virus interactions. By leveraging the evolutionary capability of trVLP mediated by error-prone RNA replication, we screened for RBD variants that evade the antibody-mediated inhibition of cell entry. Together, these findings underscore the utility of the trVLP as a safe, rapid, and flexible platform for dissecting SARS-CoV-2 RBD evolution and identifying key adaptive mutations with implications for surveillance and countermeasure development.
2025-08-06 | GSE302091 | GEO
Project description:The continuous evolution of SARS-CoV-2 poses global health challenges. A safe, rapid, and versatile method for assessing functions of Spike protein mutations in ACE2 receptor binding and immune evasion would be highly valuable. To address this, we engineered a transcription- and replication-competent virus-like particle (trVLP) derived from the Sindbis virus, pseudotyped with the SARS-CoV-2 receptor binding domain (RBD). This trVLP exclusively propagates in BHK-21 cell engineered to express both RNA replicase and human ACE2, providing a controllable, safe model of SARS-CoV-2 RBD-ACE2 interaction mediated virus entry. The system enables characterization of RBD interactions with ACE2 from various mammalian hosts, demonstrating its utility for studying host-virus interactions. By leveraging the evolutionary capability of trVLP mediated by error-prone RNA replication, we screened for RBD variants that evade the antibody-mediated inhibition of cell entry. Together, these findings underscore the utility of the trVLP as a safe, rapid, and flexible platform for dissecting SARS-CoV-2 RBD evolution and identifying key adaptive mutations with implications for surveillance and countermeasure development.
2025-08-06 | GSE302090 | GEO
Project description:The continuous evolution of SARS-CoV-2 poses global health challenges. A safe, rapid, and versatile method for assessing functions of Spike protein mutations in ACE2 receptor binding and immune evasion would be highly valuable. To address this, we engineered a transcription- and replication-competent virus-like particle (trVLP) derived from the Sindbis virus, pseudotyped with the SARS-CoV-2 receptor binding domain (RBD). This trVLP exclusively propagates in BHK-21 cell engineered to express both RNA replicase and human ACE2, providing a controllable, safe model of SARS-CoV-2 RBD-ACE2 interaction mediated virus entry. The system enables characterization of RBD interactions with ACE2 from various mammalian hosts, demonstrating its utility for studying host-virus interactions. By leveraging the evolutionary capability of trVLP mediated by error-prone RNA replication, we screened for RBD variants that evade the antibody-mediated inhibition of cell entry. Together, these findings underscore the utility of the trVLP as a safe, rapid, and flexible platform for dissecting SARS-CoV-2 RBD evolution and identifying key adaptive mutations with implications for surveillance and countermeasure development.
2025-08-06 | GSE302087 | GEO
Project description:The spike glycoprotein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mediates binding to the ACE2 receptor and subsequent membrane fusion. It exists in a range of conformations, including a closed state unable to bind the ACE2 receptor, and an open state that does so but displays more exposed antigenic surface. Spikes of variants of concern (VOCs) acquired amino acid changes linked to different opening probabilities, increased SARS-CoV-2 virulence and immune evasion. Here, using hydrogen-deuterium exchange mass spectrometry (HDX-MS), we analyzed the spike of the original Wuhan isolate, G614 mutant, spike of alpha, beta, delta and omicron VOCs and the isolated ancestral receptor binding domain (RBD) - in apo state and in complex with the ACE2 receptor. We identified changes in spike dynamics that we associated with the transition from closed to open conformation, to ACE2 binding, and to specific mutations in VOCs. We show that the RBD-associated subdomain plays a role in spike opening, whereas the NTD acts as a hotspot of conformational divergence of VOC spikes driving immune evasion. Alpha, beta and delta spikes assume predominantly open conformations and a strong ACE2 binding increases the dynamics of their core helices, priming spikes for fusion. Conversely, substitutions in omicron spike lead to predominantly binding-incompetent closed conformations, presumably enabling it to escape antibodies. At the same time, its core helices show characteristics of being pre-primed for fusion even in the absence of ACE2. These data inform on SARS-CoV-2 evolution and omicron variant emergence.
2023-03-15 | PXD039762 | Pride
Project description:The rapid and escalating spread of SARS coronavirus 2 (SARS-CoV-2) poses an immediate public health emergency, and no approved therapeutics or vaccines are currently available. The viral spike protein S binds membrane-tethered ACE2 on host cells in the lungs to initiate molecular events that ultimately release the viral genome intracellularly. The extracellular protease domain of ACE2 inhibits cell entry of both SARS and SARS-2 coronaviruses by acting as a soluble decoy for receptor binding sites on S, and is a promising candidate for therapeutic and prophylactic development. Using deep mutagenesis, variants of ACE2 are identified with increased binding to the receptor binding domain of S at a cell surface. Mutations are found across the protein-protein interface and also at buried sites where they are predicted to enhance folding and presentation of the interaction epitope. The mutational landscape offers a preliminary blueprint for engineering high affinity ACE2 receptors to meet this unprecedented challenge.
2020-03-19 | GSE147194 | GEO
Project description:Abdala is a COVID-19 vaccine produced in Pichia pastoris and is based on the receptor-binding domain (RBD) of the SARS-CoV-2 spike. Abdala is currently approved for use in multiple countries with clinical trials confirming its safety and efficacy in preventing severe illness and death. Although P. pastoris is used as an expression system for protein-based vaccines, yeast glycosylation remains largely uncharacterised across immunogens. Here, we characterise N-glycan structures and their site of attachment on Abdala and show how yeast-specific glycosylation decreases binding to the ACE2 receptor and a receptor-binding motif (RBM) targeting antibody compared to the equivalent mammalian-derived RBD. Reduced receptor and antibody binding is attributed to changes in conformational dynamics resulting from N-glycosylation. These data highlight the critical importance of glycosylation in vaccine design and demonstrate how individual glycans can influence host interactions and immune recognition via protein structural dynamics.
2025-05-07 | PXD058644 | Pride
Project description:Global containment of COVID-19 still requires accessible and affordable vaccines for low- and middle-income countries (LMICs). Recently approved vaccines provide needed interventions, albeit at prices that may limit their global access. Subunit vaccines based on recombinant proteins are suited for large-volume microbial manufacturing to yield billions of doses annually, minimizing their manufacturing cost. These types of vaccines are well-established, proven interventions with multiple safe and efficacious commercial examples. Many vaccine candidates of this type for SARS-CoV-2 rely on sequences containing the receptor-binding domain (RBD), which mediates viral entry to cells via ACE2. Here we report an engineered sequence variant of RBD that exhibits high-yield manufacturability, high-affinity binding to ACE2, and enhanced immunogenicity after a single dose in mice compared to the Wuhan-Hu-1 variant used in current vaccines. Antibodies raised against the engineered protein exhibited heterotypic binding to the RBD from two recently reported SARS-CoV-2 variants of concern (501Y.V1/V2). Presentation of the engineered RBD on a designed virus-like particle (VLP) also reduced weight loss in hamsters upon viral challenge.
2021-09-09 | GSE172054 | GEO