AK15 peptide

AK15 peptide

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

Batch to batch variation of the purity

H-AKKKLSRWWLRWWVK-OH

H-Ala-Lys-Lys-Lys-Leu-Ser-Arg-Trp-Trp-Leu-Arg-Trp-Trp-Val-Lys-OH

15

95.2%

C₁₀₃H₁₅₅N₂₉O₁₇

2071.51

Synthetic

Powder

AK15 is a small mycobacteriophage-derived peptide. AK15 adopted cationic amphiphilic α-helical structure. Both AK15 and AK15–6 directly inhibited M. tb by trehalose 6, 6’-dimycolate (TDM)–binding and membrane–disruption. They both exhibited bactericidal activity, cell selectivity, and synergistic effects with rifampicin, and none induced drug resistance to M. tb. They efficiently attenuated mycobacterial load in the lung of M. tb–infected mice. AK15 and its isomer AK15–6 showed apparent affinity to mycobacterial cord factor. The pre–incubation of AK15 or AK15–6 with TDM blocked the anti–mycobacterial activity of the peptides. AK15 and its isomer AK15–6 impaired the surface morphology of M. tb. AK15 and its isomer AK15–6 increased the passive diffusion of the fluorescent dye into M. tb. AK15 and its isomer AK15–6 induced the leakage of intracellular ATP from M. tb. AK15 and its isomer AK15–6 showed cell selectivity to M. tb. Positively charged residues, aromatic residues and α–helix constitute the key structural requirements of the peptides. AK15 and its isomer AK15–6 showed none induced drug resistance to M. tb. AK15 and its isomer AK15–6 generated synergistic effects with rifampincin against M. tb. AK15 and its isomer AK15–6 exhibited thermal stability and low toxicity to mice. AK15 and its isomer AK15–6 restrained TDM-stimulated inflammatory signaling activation and inflammatory cytokine production in murine macrophages. AK15 and its isomer AK15–6 efficiently protected mice from M. tb infection. AK15 and its isomer AK15–6 enhanced modest basal immune responses in BMDMs and mice.

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

• Yang Y, Liu Z, He X, et al. A small mycobacteriophage-derived peptide and its improved isomer restrict mycobacterial infection via dual mycobactericidal-immunoregulatory activities. J Biol Chem. 2019;294(19):7615-7631

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.