Planck−Benzinger Thermal Work Function:  Thermodynamic Approach to Site-Specific S-Protein and S-Peptides Interactions in the Ribonuclease S‘ System

1997 ◽  
Vol 101 (39) ◽  
pp. 7835-7843 ◽  
Author(s):  
Paul W. Chun
Keyword(s):  
Work Function ◽  
Thermodynamic Approach ◽  
Site Specific ◽  
S Protein ◽  
Thermal Work

scholarly journals Site-specific N-glycosylation Characterization of Recombinant SARS-CoV-2 Spike Proteins

2020 ◽  
pp. mcp.RA120.002295 ◽  
Author(s):  
Yong Zhang ◽  
Wanjun Zhao ◽  
Yonghong Mao ◽  
Yaohui Chen ◽  
Shisheng Wang ◽  
...  
Keyword(s):  
Insect Cells ◽  
Host Cells ◽  
Protein Subunit ◽  
Genome Sequences ◽  
Complex Type ◽  
Site Specific ◽  
Differential Processing ◽  
S Protein ◽  
Shed Light

The glycoprotein spike (S) on the surface of SARS-CoV-2 is a determinant for viral invasion and host immune response. Herein, we characterized the site-specific N-glycosylation of S protein at the level of intact glycopeptides. All 22 potential N-glycosites were identified in the S-protein protomer and were found to be preserved among the 753 SARS-CoV-2 genome sequences. The glycosites exhibited glycoform heterogeneity as expected for a human cell-expressed protein subunit. We identified masses that correspond to 157 N-glycans, primarily of the complex type. In contrast, the insect cell-expressed S protein contained 38 N-glycans, completely of the high-mannose type. Our results revealed that the glycan types were highly determined by the differential processing of N-glycans among human and insect cells, regardless of the glycosites’ location. Moreover, the N-glycan compositions were conserved among different sizes of subunits. Our study indicate that the S protein N-glycosylation occurs regularly at each site, albeit the occupied N-glycans were diverse and heterogenous. This N-glycosylation landscape and the differential N-glycan patterns among distinct host cells are expected to shed light on the infection mechanism and present a positive view for the development of vaccines and targeted drugs.

scholarly journals Cryo-EM analysis of a feline coronavirus spike protein reveals a unique structure and camouflaging glycans

2020 ◽  
Vol 117 (3) ◽  
pp. 1438-1446 ◽  
Author(s):  
Tzu-Jing Yang ◽  
Yen-Chen Chang ◽  
Tzu-Ping Ko ◽  
Piotr Draczkowski ◽  
Yu-Chun Chien ◽  
...  
Keyword(s):  
Viral Entry ◽  
Protein Structures ◽  
Structural Features ◽  
Host Recognition ◽  
Complex Type ◽  
Site Specific ◽  
S Protein ◽  
Feline Infectious Peritonitis ◽  
Structural Insights ◽  
Feline Coronavirus

Feline infectious peritonitis virus (FIPV) is an alphacoronavirus that causes a nearly 100% mortality rate without effective treatment. Here we report a 3.3-Å cryoelectron microscopy (cryo-EM) structure of the serotype I FIPV spike (S) protein, which is responsible for host recognition and viral entry. Mass spectrometry provided site-specific compositions of densely distributed high-mannose and complex-type N-glycans that account for 1/4 of the total molecular mass; most of the N-glycans could be visualized by cryo-EM. Specifically, the N-glycans that wedge between 2 galectin-like domains within the S1 subunit of FIPV S protein result in a unique propeller-like conformation, underscoring the importance of glycosylation in maintaining protein structures. The cleavage site within the S2 subunit responsible for activation also showed distinct structural features and glycosylation. These structural insights provide a blueprint for a better molecular understanding of the pathogenesis of FIP.

scholarly journals Mucin-type O-glycosylation Landscapes of SARS-CoV-2 Spike Proteins

2020 ◽  
Author(s):  
Yong Zhang ◽  
Wanjun Zhao ◽  
Yonghong Mao ◽  
Yaohui Chen ◽  
Jingqiang Zhu ◽  
...  
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Targeted Drugs ◽  
Cell Type ◽  
Glycosylation Pattern ◽  
Site Specific ◽  
S Protein ◽  
Viral Attachment ◽  
Viral Binding ◽  
Pngase F ◽  
S Proteins

ABSTRACTThe densely glycosylated spike (S) proteins that are highly exposed on the surface of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) facilitate viral attachment, entry, and membrane fusion. We have previously reported all the 22 N-glycosites and site-specific N-glycans in the S protein protomer. Herein, we report the comprehensive and precise site-specific O-glycosylation landscapes of SARS-CoV-2 S proteins, which were characterized using high-resolution mass spectrometry. Following digestion using trypsin and trypsin/Glu-C, and de-N-glycosylation using PNGase F, we determined the mucin-type (GalNAc-type) O-glycosylation pattern of S proteins, including unambiguous O-glycosites and the 6 most common O-glycans occupying them, via Byonic identification and manual validation. Finally, 43 O-glycosites were identified in the insect cell-expressed S protein. Most glycosites were modified by non-sialylated O-glycans such as HexNAc(1) and HexNAc(1)Hex(1). In contrast, 30 O-glycosites were identified in the human cell-expressed S protein S1 subunit. Most glycosites were modified by sialylated O-glycans such as HexNAc(1)Hex(1)NeuAc(1) and HexNAc(1)Hex(1)NeuAc(2). Our results are the first to reveal that the SARS-CoV-2 S protein is a mucin-type glycoprotein; clustered O-glycans often occur in the N- and the C-termini of the S protein, and the O-glycosite and O-glycan compositions vary with the host cell type. These site-specific O-glycosylation landscapes of the SARS-CoV-2 S protein are expected to provide novel insights into the viral binding mechanism and present a strategy for the development of vaccines and targeted drugs.

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