KYL peptide

KYL peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

H-KYLPYWPVLSSL-OH

H-Lys-Tyr-Leu-Pro-Tyr-Trp-Pro-Val-Leu-Ser-Ser-Leu-OH

12

95.02%

C₇₄H₁₀₈N₁₄O₁₇

1465.73

Synthetic

Powder

KYL is an EphA4 receptor tyrosine kinase inhibitor with a Kd of 0.8 μM. KYL inhibits EphA4-EphrinA5 interactions with an IC50 of 6.34 μM. Through EphA4 inhibition, KYL can prevent dendritic spine reduction, the blocking of LTP induction and neuronal apoptosis caused by amyloid-β oligomers (AβOs). EphA4-/- neurons or sh-EphA4-transfected neurons showed reduced synaptotoxicity by AβOs. EphA4/c-Abl activation is a key-signalling event that mediates the synaptic damage induced by AβOs.

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

• Lamberto et al (2012) Distinctive binding of three antagonistic peptides to the ephrin-binding pocket of the EphA4 receptor. Biochem. J. 445 47 PMID: 22489865
• Vargas et al (2014) EphA4 activation of c-Abl mediates synaptic loss and LTP blockade caused by amyloid-β oligomers. PLoS One 9 e92309 PMID: 24658113
• Tamura et al (2020) EphA4 regulates Aβ production via BACE1 expression in neurons. FASEB J. 34(12):16383 PMID: 33090569

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.