ABSTRACT
In the present investigation, new explicit approaches by the Milstein method and increment function of the Jacobian derivative of the drift coefficient are designed. Several numerical tests such as Cox–Ingersoll–Ross process, stochastic Brusselator, and Davis-Skodje system are presented to illustrate the accuracy and the efficiency of our schemes. Furthermore, we show that the strong convergence rate of our procedures is approximately one.
ABSTRACT
The ongoing COVID-19 pandemic has highlighted the immediate need for the development of antiviral therapeutics targeting different stages of the SARS-CoV-2 life cycle. We developed a bioluminescence-based bioreporter to interrogate the interaction between the SARS-CoV-2 viral spike (S) protein and its host entry receptor, angiotensin-converting enzyme 2 (ACE2). The bioreporter assay is based on a nanoluciferase complementation reporter, composed of two subunits, large BiT and small BiT, fused to the S receptor-binding domain (RBD) of the SARS-CoV-2 S protein and ACE2 ectodomain, respectively. Using this bioreporter, we uncovered critical host and viral determinants of the interaction, including a role for glycosylation of asparagine residues within the RBD in mediating successful viral entry. We also demonstrate the importance of N-linked glycosylation to the RBD's antigenicity and immunogenicity. Our study demonstrates the versatility of our bioreporter in mapping key residues mediating viral entry as well as screening inhibitors of the ACE2-RBD interaction. Our findings point toward targeting RBD glycosylation for therapeutic and vaccine strategies against SARS-CoV-2.
Subject(s)
Angiotensin-Converting Enzyme 2/chemistry , Antibodies, Neutralizing/pharmacology , Biological Assay , Lectins/pharmacology , Receptors, Virus/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Asparagine/chemistry , Asparagine/metabolism , Binding Sites , COVID-19/diagnosis , COVID-19/immunology , COVID-19/virology , Genes, Reporter , Glycosylation/drug effects , HEK293 Cells , Host-Pathogen Interactions/drug effects , Host-Pathogen Interactions/genetics , Humans , Luciferases/genetics , Luciferases/metabolism , Luminescent Measurements , Protein Binding , Protein Interaction Domains and Motifs , Protein Structure, Secondary , Receptors, Virus/antagonists & inhibitors , Receptors, Virus/genetics , Receptors, Virus/immunology , SARS-CoV-2/drug effects , SARS-CoV-2/growth & development , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Virus Internalization/drug effects , COVID-19 Drug TreatmentABSTRACT
The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic presents an urgent need for an effective vaccine. Molecular characterization of SARS-CoV-2 is critical to the development of effective vaccine and therapeutic strategies. In the present study, we show that the fusion of the SARS-CoV-2 spike protein receptor-binding domain to its transmembrane domain is sufficient to mediate trimerization. Our findings may have implications for vaccine development and therapeutic drug design strategies targeting spike trimerization. As global efforts for developing SARS-CoV-2 vaccines are rapidly underway, we believe this observation is an important consideration for identifying crucial epitopes of SARS-CoV-2.