Human PD-1 Binding Peptide Ar5M_2 (PD-L1 Inhibitor V)

LDYVNRRKMYQ, designated Ar5M_2 in the original publication, is a de novo designed peptide ligand of human programmed death-1 (PD-1). It was developed by grafting key PD-L1 interface anchor features into short peptide scaffolds. Surface plasmon resonance measurements in the published study gave Ar5M_2 a dissociation constant (KD) of 3.32 ± 0.67 µM for human PD-1. The sequence therefore provides a defined reagent for studying peptide recognition of the PD-1/PD-L1 protein-protein interaction interface.

• PD-1 peptide-binding studies
• PD-1/PD-L1 interaction research
• immune-checkpoint peptide structure-function studies
• surface plasmon resonance and binding-assay development

The published 3.32 µM value is a PD-1 binding KD measured for Ar5M_2. The strongest functional PD-1/PD-L1 blocking evidence in the same study was reported for Ar5Y_4; do not automatically assign Ar5Y_4 cellular activity to Ar5M_2 without direct testing.

1. Discovery of peptide inhibitors targeting human programmed death 1 (PD-1) receptor