Chionodracine [F1W; H4,15,17K; I9K; S11,21K] peptide

Chionodracine [F1W; H4,15,17K; I9K; S11,21K] peptide

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

H-WFGKLYRGKTKVVKKVKGLLKG-OH

H-Trp-Phe-Gly-Lys-Leu-Tyr-Arg-Gly-Lys-Thr-Lys-Val-Val-Lys-Lys-Val-Lys-Gly-Leu-Leu-Lys-Gly-OH

22

95.2%

C₁₂₂H₂₀₅N₃₃O₂₅

2534.13

Synthetic

Powder

The increasing resistance to conventional antibiotics is an urgent problem that can be addressed by the discovery of new antimicrobial drugs such as antimicrobial peptides (AMPs). AMPs are components of innate immune system of eukaryotes and are not prone to the conventional mechanisms that are responsible of drug resistance. Fish are an important source of AMPs and, recently, we have isolated and characterized a new 22 amino acid residues peptide, the chionodracine (Cnd), from the Antarctic icefish Chionodraco hamatus. In this paper we focused on a new Cnd-derived mutant peptide, namely Cnd-m3a, designed to improve the selectivity against prokaryotic cells and the antimicrobial activity against human pathogens of the initial Cnd template. Cnd-m3a was used for immunization of rabbits, which gave rise to a polyclonal antibody able to detect the peptide. The interaction kinetic of Cnd-m3a with the Antarctic bacterium Psychrobacter sp. (TAD1) was imaged using a transmission electron microscopy (TEM) immunogold method. Initially the peptide was associated with the plasma membrane, but after 180 min of incubation, it was found in the cytoplasm interacting with a DNA target inside the bacterial cells. Using fluorescent probes we showed that the newly designed mutant can create pores in the outer membrane of the bacteria E. coli and Psychrobacter sp. (TAD1), confirming the results of TEM analysis. Moreover, in vitro assays demonstrated that Cnd-m3a is able to bind lipid vesicles of different compositions with a preference toward negatively charged ones, which mimics the prokaryotic cell. The Cnd-m3a peptide showed quite low hemolytic activity and weak cytotoxic effect against human primary and tumor cell lines, but high antimicrobial activity against selected Gram - human pathogens. These results highlighted the high potential of the Cnd-m3a peptide as a starting point for developing a new human therapeutic agent.

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

• Buonocore F, Picchietti S, Porcelli F, Della Pelle G, Olivieri C, Poerio E, Bugli F, Menchinelli G, Sanguinetti M, Bresciani A, Gennari N, Taddei AR, Fausto AM, Scapigliati G. Fish-derived antimicrobial peptides: Activity of a chionodracine mutant against bacterial models and human bacterial pathogens. Dev Comp Immunol. 2019 Jul;96:9-17. doi: 10.1016/j.dci.2019.02.012. Epub 2019 Feb 18. PMID: 30790604.

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.