MLCK inhibitor peptide 18

MLCK inhibitor peptide 18

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

H-RKKYKYRRK-NH2

H-Arg-Lys-Lys-Tyr-Lys-Tyr-Arg-Arg-Lys-NH2

9

95.44%

C₆₀H₁₀₅N₂₃O₁₁

1324.62

Synthetic

Powder

MLCK inhibitor peptide 18 is a selective cell permeable inhibitor of myosin light chain kinase with an IC50 of 50 nM. MLCK inhibitor peptide 18 displays 4000-fold selectivity over CaM kinase II and does not inhibit PKA. In vitro and in vivo treatment with the MLCK inhibitor peptide 18 attenuates the increased epithelial monolayer permeability and occludin endocytosis caused by intestinal anoxia/reoxygenation (A/R) injury.

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

• Lukas et al (1999) Identification of novel classes of protein kinase inhibitors using combinatorial peptide chemistry based on functional genomics knowledge. J.Med.Chem. 42 910 PMID: 10072688
• Jin and Blikslager (2016) Myosin light chain kinase mediates intestinal barrier dysfunction via occludin endocytosis during anoxia/reoxygenation injury. American J. Physiology-Cell Physiology 311(6) C996 PMID: 27760753
• Huang et al (2020) Wogonoside alleviates colitis by improving intestinal epithelial barrier function via the MLCK/pMLC2 pathway. Phytomedicine 68 153179 PMID: 32062328

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.