ArticleFrontiers in immunology2025
Comprehensive N-glycosylation profiling of recombinant spike S1 protein from the wild-type SARS-CoV-2 and its variants.
Article in Frontiers in immunology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
14 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Introduction: By 2024, COVID-19 has become endemic, with new variants contributing to its continued spread. The Spike protein forms trimers that bind to the ACE2 receptor on host cells, with the S1 subunit being a primary target for vaccines and antiviral treatments. Methods: Herein, we performed an in-depth analysis of the N-glycosylation of the recombinant Spike S1 protein (S1 protein) across the wild-type (WT) virus and its 5 variants, including Alpha, Beta, Gamma, Delta, and Lambda, by integrating ultrahigh-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF MS) and unique TiO₂-PGC chip-based LC/MS techniques. Results: A total of 332 glycan structures arising from 180 compositions on the S1 and RBD regions were identified, revealing remarkable glycosylation diversity of the S1 protein. Complex glycan was shown to be the dominant structure across variants. Neutral N-glycans are mainly di-antennary with two fucosyl groups, while the majority of acidic N-glycans were multi-antennary with mono-fucosyl residues. In addition, sialic acid linkages of the N-glycans were extensively studied by utilizing ¹³C-labeled standards and specific enzymes for the first time, showing the existence of both α-2,3 and α-2,6 linkages across WT and five variants. It should be noted that the Lambda variant shows more complex α-2,3 and α-2,6-linked glycans in the RBD region, which may potentially enhance its glycan shield effect. Acetylated glycans, which were identified on S protein for the first time, were found to be fully fucosylated on the S1 region and sialylated on the RBD region across all variants. UHPLC-TOF MS analysis revealed unoccupied N-glycosylation sites in S1-Gamma (N657), S1-Delta (N61), and S1-Lambda (N17, N61, N657), with N17 and N61 showing low glycan occupancy (0%-3.4%), suggesting these sites may lack glycan shield protection. Discussion: This study provides a comprehensive N-glycosylation profile of the S1 protein across different variants, offering an essential structural basis for future vaccine development and research on viral functions.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.