O-glycosylation pattern of the SARS-CoV-2 spike protein reveals an “O-Follow-N” rule

Extensive glycosylation of the spike protein of SARS-CoV-2 virus not only shields the major part of it from host immune responses, but glycans at specific sites also act on its conformation dynamics and contribute to efficient host receptor binding, and hence infectivity. As variants of concern arise during the course of the COVID-19 pandemic, it is unclear if mutations accumulated within the spike protein would affect its site-specific glycosylation pattern. The Alpha variant derived from the D614G lineage is distinguished from others by having deletion mutations located right within an immunogenic supersite of the spike N-terminal domain that make it refractory to most neutralizing antibodies directed against this domain. Despite maintaining an overall similar structural conformation, our mass spectrometry-based site-specific glycosylation analyses of similarly produced spike proteins with and without the D614G and Alpha variant mutations reveal a significant shift in the processing state of N-glycans on one specific N-terminal domain site. Its conversion to a higher proportion of complex type structures is indicative of altered spatial accessibility attributable to mutations specific to the Alpha variant that may impact its transmissibility. This and other more subtle changes in glycosylation features detected at other sites provide crucial missing information otherwise not apparent in the available cryogenic electron microscopy-derived structures of the spike protein variants.

Download Full-text

First antibody against COVID-19 spike protein enters phase I

Nature Reviews Drug Discovery ◽

10.1038/d41573-020-00108-x ◽

2020 ◽

Vol 19 (7) ◽

pp. 435-435

Author(s):

Asher Mullard

Keyword(s):

Phase I ◽

Spike Protein

Download Full-text

Abnormal type I collagen glycosylation pattern and cross-linking in a cyclophilin B KO mouse model of recessive osteogenesis imperfecta

Bone Abstracts ◽

10.1530/boneabs.1.pp501 ◽

2013 ◽

Author(s):

Wayne Cabral ◽

Irina Perdivara ◽

MaryAnn Weis ◽

Masahiko Terajima ◽

Angela Blissett ◽

...

Keyword(s):

Mouse Model ◽

Osteogenesis Imperfecta ◽

Type I Collagen ◽

Cross Linking ◽

Type I ◽

Glycosylation Pattern ◽

Cyclophilin B

Download Full-text

Thermodynamics of the interaction between the spike protein of severe acute respiratory syndrome- coronavirus-2 and the receptor of human angiotensin converting enzyme 2. Effects of possible ligands

10.26434/chemrxiv.12186624.v3 ◽

2020 ◽

Author(s):

Cristina Garcia-Iriepa ◽

Cecilia Hognon ◽

Antonio Francés-Monerris ◽

Isabel Iriepa ◽

Tom Miclot ◽

...

Keyword(s):

Angiotensin Converting Enzyme ◽

Molecular Mechanisms ◽

Molecular Design ◽

Binding Free Energy ◽

Transmembrane Protein ◽

Spike Protein ◽

Converting Enzyme ◽

Angiotensin Converting Enzyme 2 ◽

Rational Molecular Design ◽

Rational Evaluation

<div><p>Since the end of 2019, the coronavirus SARS-CoV-2 has caused more than 180,000 deaths all over the world, still lacking a medical treatment despite the concerns of the whole scientific community. Human Angiotensin-Converting Enzyme 2 (ACE2) was recently recognized as the transmembrane protein serving as SARS-CoV-2 entry point into cells, thus constituting the first biomolecular event leading to COVID-19 disease. Here, by means of a state-of-the-art computational approach, we propose a rational evaluation of the molecular mechanisms behind the formation of the complex and of the effects of possible ligands. Moreover, binding free energy between ACE2 and the active Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein is evaluated quantitatively, assessing the molecular mechanisms at the basis of the recognition and the ligand-induced decreased affinity. These results boost the knowledge on the molecular grounds of the SARS-CoV-2 infection and allow to suggest rationales useful for the subsequent rational molecular design to treat severe COVID-19 cases.</p></div>

Download Full-text

Sitagliptin: a potential drug for the treatment of SARS-CoV-2?

10.31222/osf.io/78mbt ◽

2020 ◽

Author(s):

Sanaa Bardaweel

Keyword(s):

Clinical Trials ◽

Drug Discovery ◽

Antimalarial Drug ◽

Drug Repurposing ◽

Spike Protein ◽

Diabetic Patients ◽

Potential Drug ◽

Chemokine Production ◽

Drug Discovery And Development ◽

Sequence Identity

Recently, an outbreak of fatal coronavirus, SARS-CoV-2, has emerged from China and is rapidly spreading worldwide. As the coronavirus pandemic rages, drug discovery and development become even more challenging. Drug repurposing of the antimalarial drug chloroquine and its hydroxylated form had demonstrated apparent effectiveness in the treatment of COVID-19 associated pneumonia in clinical trials. SARS-CoV-2 spike protein shares 31.9% sequence identity with the spike protein presents in the Middle East Respiratory Syndrome Corona Virus (MERS-CoV), which infects cells through the interaction of its spike protein with the DPP4 receptor found on macrophages. Sitagliptin, a DPP4 inhibitor, that is known for its antidiabetic, immunoregulatory, anti-inflammatory, and beneficial cardiometabolic effects has been shown to reverse macrophage responses in MERS-CoV infection and reduce CXCL10 chemokine production in AIDS patients. We suggest that Sitagliptin may be beneficial alternative for the treatment of COVID-19 disease especially in diabetic patients and patients with preexisting cardiovascular conditions who are already at higher risk of COVID-19 infection.

Download Full-text