The scientific community is relentlessly working to investigate and fight SARS-CoV-2. Miltenyi Biotec stands committed to assisting those researchers in getting on top of COVID-19.
SARS-CoV-2 antigens offer researchers the possibility to investigate virus-specific immune responses, including antigen-specific B cells and antibodies.
Overview of our antigens for SARS-CoV-2 research. All antigens are available with or without biotinylation:
|SARS-CoV-2 variant||Protein||Sequence part||Product page|
|n/a||ACE2||Full length (with CLD)||Recombinant Human ACE2 (HEK)|
|Truncated (w/o CLD)||Recombinant Human ACE2 (insect cells)|
|Wuhan wild-type variant||Spike protein||Spike trimer (ectodomain)||Recombinant SARS-CoV-2 Spike-Trimer (HEK)|
|Spike monomer (ectodomain)||Recombinant SARS-CoV-2 Spike-Prot (HEK)|
|Furin cleavage site (and control)||SARS-CoV-2 Furin Cleavage Site|
|Receptor binding domain (RBD)||Recombinant SARS-CoV-2 RBD (HEK)|
|Recombinant SARS-CoV-2 RBD (insect cells)|
|S1||Recombinant SARS-CoV-2 Spike-S1 (HEK)|
|S2||Recombinant SARS-CoV-2 Spike-S2 (insect cells)|
|Nucleoprotein||Full length||Recombinant SARS-CoV-2 Nucleoprotein|
|Envelope protein||C-terminus||SARS-CoV-2 Envelope C-term|
|N-terminus||SARS-CoV-2 Envelope N-term|
|Helical segment 2 (H2)||SARS-CoV-2 Envelope H2|
|B.1.1.7 variant||Spike protein||RBD||Recombinant SARS-CoV-2 RBD B.1.1.7 (HEK)|
Detection of patient-derived antibodies against SARS-CoV-2 antigens via a bead-based immunoassay
Biotinylated recombinant proteins coupled to streptavidin-coated PMMA beads can be applied to detect SARS-CoV-2–specific antibodies in plasmapheresis samples of COVID-19+ patients. The complete protocol can be found here.
Cell-based assay to analyze the binding of spike protein to native ACE2
The combination of recombinant spike RBD, monomer or trimer, and ACE2-expressing cells can be used to mimic the binding of SARS-CoV-2 to its host cells in vitro. Such binding assays can be applied to study inhibitory/neutralizing effects of components or antibodies.
Angiotensin-converting enzyme 2 (ACE2, also known as ACEH) is a transmembrane protein, which acts as receptor for SARS-CoV, SARS-CoV-2, and other coronaviruses. The large extracellular peptidase domain of ACE2 is known to interact with the spike protein of coronaviruses. The small C-terminal collectrin-like domain (CLD) has recently been described to mediate homo-dimerization of ACE2.
We offer Recombinant Human ACE2 produced in HEK cells including C-terminal CLD or insect cell–derived ACE2 lacking CLD. The potential influence of the CLD domain is indicated by the exemplary analysis below.
The surface or spike (S) glycoprotein plays a critical role in coronavirus infection as it is crucial for recognition and fusion of the virus with the host cell membrane. Two different functional domains of the S protein are responsible for these individual processes: The S1 domain contains the receptor binding domain, which binds to the host cell receptor ACE2, whereas membrane fusion is mediated via the S2 domain. Furthermore, cleavage at the furin cleavage site at the boundary of the S1 and S2 domains (aa residues 682 and 685) via cellular proteases primes the protein for entry into the host cell. Upon fusion of the viral envelope to the host cell membrane, the viral genome enters the host cell and viral replication starts.
In its active form, the spike protein is displayed as a homotrimeric structure on the surface of the SARS-CoV-2 virus.
We offer the recombinant SARS-CoV-2 spike trimer produced in HEK cells:
Our Recombinant SARS-CoV-2 Spike-Trimer (HEK) covers the ectodomain of the viral surface protein, including the S1 and S2 domain (aa V16 to K1211). The recombinant protein contains stabilizing proline substitutions at position K986P and V987P as well as a mutated furin cleavage site (RRAR to GSAG substitution at residues 682–685). A T4 fibritin trimerization motif induces the conformation of a highly stable native-like homotrimer.
Recombinant SARS-CoV-2 Spike-Trimer (HEK)
In vivo, three spike monomers form a homotrimeric structure on the surface of the SARS-CoV-2 virus; however, only one monomer appears to interact with the host cell receptor.
We offer the recombinant SARS-CoV-2 spike monomer produced in HEK cells:
Our Recombinant SARS-CoV-2 Spike-Prot (HEK) covers the ectodomain of the viral surface protein, including the S1 and S2 domain (aa V16 to K1211). The recombinant protein contains stabilizing proline substitutions at position K986P and V987P as well as a mutated furin cleavage site (RRAR to GSAG substitution at residues 682–685).
Recombinant SARS-CoV-2 Spike-Prot (HEK)
The junction connecting the S1 and S2 domain of the spike protein contains a furin cleavage site at position R682–R685 (RRAR). Recent structural studies on the SARS-CoV-2 spike protein showed that this part of the protein is solvent-exposed and disordered.
We offer synthesized polypeptides as antigens for the furin cleavage site and a control with a mutated furin cleavage site (RRAR to GSAG substitution).
SARS-CoV-2 Furin Cleavage Site and SARS-CoV-2 Furin Cleavage Site Control
The receptor binding domain (RBD) locates C-terminally within the S1 subunit of the S protein. The S protein forms a homotrimeric structure on the surface of the SARS-CoV-2 virus. Recent studies have shown that the predominant activated form of the protein S trimer displays one RBD rotated up into an ACE2-accessible state. Binding of RBD to ACE2 is a major contributor for interaction of protein S with its target receptor.
We offer recombinant SARS-CoV-2 RBD produced in HEK or insect cells:
Recombinant SARS-CoV-2 RBD
The S1 domain is localized at the N-terminus of the spike protein. This subunit is crucial for virus–host cell interaction as it contains the receptor binding domain (RBD), which recognizes and binds the host cell target receptor ACE2.
We offer recombinant SARS-CoV-2 spike S1 produced in HEK cells:
Recombinant SARS-CoV-2 Spike-S1 (HEK)
The S2 domain is localized at the C-terminus of the spike protein and mediates membrane penetration as well as virus-to-cell fusion through the presence of so-called heptad repeats.
We offer recombinant SARS-CoV-2 spike S2 produced in insect cells:
Our SARS-CoV-2 Spike-S2 covers amino acids S686 to K1211 and contains stabilizing proline substitutions at position K986P and V987P.
The SARS-CoV-2 nucleoprotein (also known as nucleocapsid protein or protein N) is a key structural protein of the SARS-CoV-2 virus. The N-terminal RNA-binding domain (NTD) associates with the viral genome of SARS-CoV-2. An intrinsically disordered stretch connects the NTD domain with the C-terminal dimerization domain (CTD). A major function of protein N is the packaging of the viral genome into helical nucleocapsid structures. Additionally, it is involved in virus transcription and interacts with the viral membrane during virion assembly.
We offer recombinant SARS-CoV-2 nucleoprotein (full length):
The envelope protein (also known as envelope small membrane protein) is localized on the surface of the virus and represents one of the most relevant structural proteins of SARS-CoV-2. It acts as a viroporin and is involved in virus morphogenesis, assembly, and pathogenesis. Based on previous structural studies of highly similar envelope proteins from other coronaviruses and homology studies, it is assumed that the envelope protein forms a pentameric structure when integrated into the membrane of SARS-CoV-2.
We offer synthesized polypeptides for three parts of the envelope protein: C- terminus, N-terminus, and helical segment 2 (H2).
If you have further questions or are interested in our proteins for SARS-CoV-2 research, please specify your question or request in the contact form and we will come back to you: