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Related Protein Products

Immune Checkpoint Proteins

R&D Systems offers an extensive range of bioactive immune checkpoint proteins. In addition to known proteins such as PD-1, PD-L1, CTLA-4, and CD28, we offer many lesser-known immune checkpoint proteins that exhibit similar co-inhibitory effects.

Fluorescent Proteins for CAR-T Research

Fluorescent labeled CD19, BCMA, and Siglec-2 allow for direct detection of a corresponding chimeric antigen receptor (CAR) on cells. Save time by eliminating a secondary antibody step with R&D Systems fluorescent proteins.

Custom Protein Libraries

Select from over 5000 R&D Systems proteins and we will deliver them to you in a 96-well plate. Save set up time by reducing manual pipetting and get to your experiment faster with R&D Systems Custom Protein Libaries.

Additional Resources

Application Note: Avi-tag Proteins

In this application note, Avi-tag proteins PD-L1 and CD155/PVR are used to determine binding kinetics to PD-1 and TIGIT, respectively, by surface plasmon resonance using a Biacore T200 instrument.

eBook: Current and Emerging Immune Checkpoint Targets for I-O Research

Immune checkpoint proteins play a central role in regulating the activities of different immune cell types and represent some of the most promising targets for cancer immunotherapy. This eBook highlights some of the immune checkpoint molecules that are being investigated as immuno-oncology targets, and the products that we offer for studying these molecules.

Wall Poster: A Look Inside a Tumor

Inside the tumor microenvironment, many different cell types exist in this dynamic, complex space with many different factors at play. View the immune cells that attempt to target the tumor and the tumor-mediated mechanisms that allow it to suppress the immune system. Request your copy today.

What are Avi-tag Proteins?

Avi-tag proteins are biotinylated in a site-specific manner, allowing for consistent, uniform protein biotinylation making them useful for many protein applications. Avi-tag recombinant proteins contain an extra 15 amino acid sequence, the Avi-tag, typically fused to the N- or C-terminus of the protein. This Avi-tag peptide is recognized by BirA ligase which enzymatically attaches a biotin molecule to the lysine residue within the Avi-tag sequence. Because the Avi-tag is on the end of the protein, the effect on protein activity is greatly diminished. The result is a biotinylated protein that maintains the same characteristics as the unlabeled protein. By taking advantage of the many different streptavidin conjugated surfaces available, Avi-tag proteins are becoming the preferred biotinylated protein for studying protein interactions.