SARS-CoV-2 RBD Peptide and Glycopeptide Array

 

 

Coronavirus Disease 2019 (COVID-19), an infectious disease resulting from the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, has ravaged the world since December 2019. Throughout history, there have been several coronavirus outbreaks, including Severe Acute Respiratory Syndrome (SARS) during 2002-2003 in South East Asia and Middle East Respiratory Syndrome (MERS) in 2012 in the Middle East and 2015 in Korea. However, none of these outbreaks caused such a significant impact on public health as COVID-19.

 

Coronavirus enters the host cells by either host receptor-mediated fusion or fusing after being swallowed into an endosome.For example, the spike (S) protein of SARS-CoV-2 plays a vital role in receptor recognition and the cell membrane fusion process.The spike (S) protein comprises two subunits, S1 and S2.The S1 subunit contains a receptor-binding domain (RBD) that recognizes and binds to the host receptor, while the S2 subunit mediates viral cell membrane fusion.For example, SARS-CoV-2 viruses utilize the human angiotensin-converting enzyme 2 (ACE2) type I membrane protein as an entry receptor. Upon binding to the ACE2 receptor by viral S protein, with the help of transmembrane serine protease 2 (TMPRSS2) on the cell surface, SARS-CoV-2 enters the host cells through direct membrane fusion. Therefore, identifying and characterizing host RBD-binding protein will accelerate our understanding of the virus and potentially unveil new targets for therapeutic interventions. As the humoral immune response is a central part of SARS-CoV-2 – elicited immunity, uncovering potent RBD-neutralizing antibodies is essential for developing new modalities to tackle the virus.

 

Z Biotech has developed a robust microarray platform that allows researchers to identify, profile, and compare specific IgG, IgA, and IgM antibody responses or detect and validate protein interactions with various RBD peptides and glycopeptides in a customizable format. Researchers can choose from a list of 83 wild-type and mutant RBD peptides and glycopeptides (15-mer in length), including sequences from the Alpha, Beta, Gamma, Delta, Omicron, and other SARS-CoV-2 variants. The selected peptides/glycopeptides are immobilized on a solid microarray surface for high-throughput binding analysis.

 

 

Features

•  Distinct RBD peptides or glycopeptides

•  Unrivaled sensitivity and specificity

•  Simple assay format

•  Small sample volume

•  Assay service available

 

 

Applications

•  Profile antibody responses from the patient or animal sera

•  Screen and characterize immunodominant RBD epitopes

•  Compare antibody responses across various RBD mutants

•  Identify RBD-interacting proteins

 

 

SARS-CoV-2 spike RBD antibodies differentially interact with RBD peptides

 

35 RBD peptides, either WT or mutant, were selected to create a custom microarray. This RBD microarray was assayed with two commercially available SARS-CoV-2 (2019-nCoV) spike RBD antibodies (rabbit PAb, 1:300), followed by a secondary antibody (anti-rabbit-IgG, Cy3). The array was scanned with a microarray scanner at 532nm wavelength. Positive control 3 (PC3, rabbit IgG) showed binding signals as expected, as well as multiple RBD peptides. Negative control (NC) showed no binding signal.

Both AB1 and AB2 bind to WT RBD peptide 9 (PR9). For the same peptide, the bindings to K417N (PR10) and K417T (PR11) mutants are lost. AB2 binds with WT peptide 14 (RP14) while completely losing its binding capacity to the Omicron mutant (RP15).

 

 

List of peptides and glycopeptides for custom RBD microarray (download the PDF)

List of peptides for custom RBD microarray; additional peptides available upon request. 

 

 

 

10614-8S         SARS-CoV-2 RBD Peptide and Glycopeptide Array Slide (8 samples)

10614-16S        SARS-CoV-2 RBD Peptide and Glycopeptide Array Slide (16 samples)

10614-8K         SARS-CoV-2 RBD Peptide and Glycopeptide Array *Assay Kit (8 samples)

10614-16K        SARS-CoV-2 RBD Peptide and Glycopeptide Array *Assay Kit (16 samples)

 

* The assay kit contains a microarray slide, a bottle of blocking buffer, a bottle of assay buffer, a hybridization chamber, and sealing films. The hybridization chamber is a device that holds the array slide, assay buffer, and samples to be analyzed. 

 

 

 

List of bacterial glycans on the array (download the PDF)

Protocol & User Manual (download the manual)