Mel4 peptide

Mel4 peptide

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

H-KNKRKRRRRRRGGRRRR-OH

H-Lys-Asn-Lys-Arg-Lys-Arg-Arg-Arg-Arg-Arg-Arg-Gly-Gly-Arg-Arg-Arg-Arg-OH

17

95.2%

C₉₂H₁₈₂N₅₄O₁₉

2348.77

Synthetic

Powder

Melimine and Mel4 are chimeric cationic peptides with broad-spectrum antimicrobial activity. They have been shown to be highly biocompatible in animal models and human clinical trials. The current study examined the mechanism of action of these two antimicrobial peptides against P. aeruginosa. The efect of the peptides of endotoxin neutralization, and their interactions with cytoplasmic membranes using DiSC(3)-5 and Sytox green, Syto-9 and PI dyes were analysed. Release of ATP and DNA/RNA were determined using ATP luminescence and increase in OD260nm. The bacteriolytic ability of the peptides was determined by measuring decreases in OD620nm. Both the peptides neutralized LPS suggesting their interaction with lipid A. Cytoplasmic membrane was disrupted within 30seconds, which correlated with reductions in cellular viability. At 2minutes melimine or Mel4, released 75% and 36% cellular ATP respectively (P<0.001). Membrane permeabilization started 5minutes with simultaneous release of DNA/RNA. Flow cytometry demonstrated 52% and 18% bacteria were stained with PI after 30minutes. Overall, melimine showed higher capacity for membrane disruption compared to Mel4 (P<0.001). The fndings of this study have been summarized as a timeline of bactericidal activity, suggesting that the peptides permeabilized P. aeruginosa within 5minutes, started lysis within 2hours of exposure.

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

• Yasir M, Dutta D, Willcox MDP. Comparative mode of action of the antimicrobial peptide melimine and its derivative Mel4 against Pseudomonas aeruginosa [published correction appears in Sci Rep. 2019 Sep 10;9(1):13267]. Sci Rep. 2019;9(1):7063. Published 2019 May 8. doi:10.1038/s41598-019-42440-2

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.