Camelid antibodies are used in many forms of research including studying of protein structure, high resolution imaging applications, drug delivery, as well as detection and neutralization of viruses. Due to the smaller size, these antibodies can detect epitopes that are more difficult to reach than the conventional antibody.
R&D Systems utilizes our recombinant antibody engineering expertise to offer multiple forms of camelid antibodies in our LlaMABody™ product line. We offer:
Native llama heavy chain IgG antibodies
VHH antibody domain conjugated to His-tag for convenient detection
VHH domains on a human IgG scaffold
The SARS-CoV-1/2 Spike RBD Llamabody™ Antibody is based on the published SARS VHH-72 clone. The SARS-CoV-1/2 Spike RBD Llamabody™ Antibody is a recombinantly expressed antibody that has the VHH domain of the SARS VHH-72 clone fused to a human IgG heavy chain scaffold. With the small size of this fusion antibody structure lending to the ability to reach more difficult epitopes, this product has the ability to block both SARS-CoV-1 and SARS-CoV-2. We have recently introduced a smaller His-tagged VHH domain Llamabody™ (Catalog # LMAB10869) that blocks binding of SARS-CoV-2 Spike RBD to ACE-2 transfected cells in an equivalent manner to the VHH-72 fusion clone.
In addition to the SARS Spike RBD Llamabody™ antibodies, we offer His-tagged VHH domain Llamabody Antibodies targeting Siglec-2 and Siglec-3 in our retail catalog.
Camelid antibodies are antibodies from the Camelidae family of mammals that include llamas, camels, and alpacas. These animals produce 2 main types of antibodies. One type of antibody camelids produce is the conventional antibody that is made up of 2 heavy chains and 2 light chains. They also produce another type of antibody that is made up of only 2 heavy chains. This is known as heavy chain IgG (hcIgG). While these antibodies do not contain the CH1 region, they retain an antigen binding domain called the VHH region. VHH antibodies, also known as single domain antibodies or Nanobodies®, contain only the VHH region from the camelid antibody.
Advantages of Camelid Antibodies
VHH antibodies can provide many benefits over traditional IgG antibodies. VHH antibodies are about 15kDa in size compared to the 150kDa size of an IgG antibody. Due to their smaller size they are able to detect certain epitopes that may not have been accessible in blocking and with flow cytometry staining in live cells with a traditional antibody due to steric hindrance. They are also able to penetrate fixed tissue and enter cells easier allowing for more specific IHC staining and intracellular flow cytometry staining. The VHH antibodies are also more stable and can withstand a larger pH and temperature range.
At R&D Systems, we have optimized a modular platform for custom recombinant antibody development and are able to provide additional products that may not be found in our catalog. By using our extensive recombinant antibody knowledge, we are able to provide custom LlaMABody products that include VHH antibodies (single domain antibodies), bivalent VHH antibodies and VHH domains fused to IgG backbones from a variety of species.