D-K6L9 peptide

D-K6L9 peptide

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

H-LKLLKKLLKKLLKLL-NH2, Leucines 3 and 8, and lysines 6,9 and 13 are D enantiomers

H-Leu-Lys-Leu-Leu-Lys-Lys-Leu-Leu-Lys-Lys-Leu-Leu-Lys-Leu-Leu-NH2, Leucines 3 and 8, and lysines 6,9 and 13 are D enantiomers

15

95.12%

C₉₀H₁₇₄N₂₂O₁₅

1804.48

Synthetic

Powder

D-K6L9 is a host defense–like peptide composed of six lysines and nine leucines, modified by the inclusion of D-amino acids to improve antimicrobial activity and resistance to degradation by proteases. D-K6L9 shows antimicrobial and antibiofilm activities against Pseudomonas aeruginosa from cystic fibrosis patients without inducing bacterial resistance. In addition to its antimicrobial properties, in animal models D-K6L9 is able to target and arrest the growth of aggressive and hormone-resistant primary human prostate and breast tumours and prevent metastasis, effects which are correlated with increased necrosis of the tumour cells and a decrease in the tumour microvessel density. The selectivity of D-K6L9 derives from specific binding to surface phosphatidylserine and the killing of the cancer cells via cytoplasmic membrane depolarization.

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

• Papo (2004) Suppression of human prostate tumor growth in mice by a cytolytic D-, L-amino Acid Peptide: membrane lysis, increased necrosis, and inhibition of prostate-specific antigen secretion. Cancer Res. 64(16) 5779 PMID: 15313920
• Papo et al (2006) Inhibition of tumor growth and elimination of multiple metastases in human prostate and breast xenografts by systemic inoculation of a host defense-like lytic peptide. Cancer Res. 66(10) 5371 PMID: 16707464
• Ben Hur et al (2022) Antimicrobial Peptides against Multidrug-Resistant Pseudomonas aeruginosa Biofilm from Cystic Fibrosis Patients. J Med Chem. 2022 65(13) 9050 PMID: 35759644

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.