RK-10, a specific PD-L1 binding peptide

RK-10, a specific PD-L1 binding peptide

• COA/MS/HPLC Report
• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

GSGSGSTYLCGAISLAPKAQIKESL

H-Gly-Ser-Gly-Ser-Gly-Ser-Thr-Tyr-Leu-Cys-Gly-Ala-Ile-Ser-Leu-Ala-Pro-Lys-Ala-Gln-Ile-Lys-Glu-Ser-Leu-OH

25

95.01%

C₁₀₅H₁₇₆N₂₈O₃₆S₁

2438.74

Synthetic

Powder

RK-10, a specific PD-L1 binding peptide, could be used for detecting PD-L1 expressing tumors with immunohistochemistry or flow cytometry. Flow cytometry was performed on cell lines and patient tissues using a fluorescent peptide (RK-10-Cy5). Immunohistochemistry using a biotin-modified peptide (RK-10-Biotin) was tested against the FDA-approved SP263 clone on biopsied patient tissues. RK-10 shows staining in the tumor regions of FFPE tissues where the SP263 kit does not. RK-10-Cy5 peptide also demonstrates PD-L1 detection in NSCLC, breast, squamous cell carcinoma, and melanoma.

Normally, this peptide will be delivered in lyophilized form and should be stored in a freezer at or below -20 °C. For more details, please refer to the manual: Handling and Storage of Synthetic Peptides

• Caldwell, C., Johnson, C. E., Balaji, V. N., Balaji, G. A., Hammer, R. D., & Kannan, R. (2017). Identification and Validation of a PD-L1 Binding Peptide for Determination of PDL1 Expression in Tumors. Scientific Reports, 7(1).
• Chavda VP, Solanki HK, Davidson M, Apostolopoulos V, Bojarska J. Peptide-Drug Conjugates: A New Hope for Cancer Management. Molecules. 2022 Oct 25;27(21):7232. doi: 10.3390/molecules27217232. PMID: 36364057; PMCID: PMC9658517.

Trifluoroacetic acid (TFA) has a significant impact on peptides due to its role in the peptide synthesis process.

TFA is essential for the protonation of peptides that lack basic amino acids such as Arginine (Arg), Histidine (His), and Lysine (Lys), or ones that have blocked N-termini. As a result, peptides often contain TFA salts in the final product.

TFA residues, when present in custom peptides, can cause unpredictable fluctuations in experimental data. At a nanomolar (nM) level, TFA can influence cell experiments, hindering cell growth at low concentrations (as low as 10 nM) and promoting it at higher doses (0.5–7.0 mM). It can also serve as an allosteric regulator on the GlyR of glycine receptors, thereby increasing receptor activity at lower glycine concentrations.

In an in vivo setting, TFA can trifluoroacetylate amino groups in proteins and phospholipids, inducing potentially unwanted antibody responses. Moreover, TFA can impact structure studies as it affects spectrum absorption.