Apolipoprotein A-I-mimetic (4F-P-4F) peptide

Apolipoprotein A-I-mimetic (4F-P-4F) peptide

• COA/MS/HPLC Report
• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

Ac-DWFKAFYDKVAEKFKEAFPDWFKAFYDKVAEKFKEAF-NH2

Ac-Asp-Trp-Phe-Lys-Ala-Phe-Tyr-Asp-Lys-Val-Ala-Glu-Lys-Phe-Lys-Glu-Ala-Phe-Pro-Asp-Trp-Phe-Lys-Ala-Phe-Tyr-Asp-Lys-Val-Ala-Glu-Lys-Phe-Lys-Glu-Ala-Phe-NH2

37

90.03%

C₂₃₁H₃₁₄N₄₈O₅₆

4659.23

Synthetic

Powder

The 18-amino acid amphipathic helical peptide Ac-DWFKAFYDKVAEKFKEAF-NH2 promotes the separation of cholesterol from the phospholipid, resulting in the formation of cholesterol crystallites, even at mole fractions of cholesterol as low as 0.3. The peptide exerts a greater degree of penetration into membranes of pure phosphatidylcholine in the absence of cholesterol than into bilayers of phosphatidylcholine and cholesterol. The circular dichroism spectrum of the peptide in buffer indicates that it self-associates, leading to the formation of structures with higher helical content. However, in the presence of lipid, the peptide remains helical over a larger concentration range. The peptide undergoes a thermal transition on heating. Cholesterol has little effect on the secondary structure of the peptide; however, increased Trp emission intensity in the absence of cholesterol indicates a deeper penetration of the helix upon removal of cholesterol from the membrane. The results with these model systems demonstrate changes in peptide-lipid interactions that may be related to the observed biological properties of this peptide.

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

• Epand RM, Epand RF, Sayer BG, Melacini G, Palgulachari MN, Segrest JP, Anantharamaiah GM. An apolipoprotein AI mimetic peptide: membrane interactions and the role of cholesterol. Biochemistry. 2004 May 4;43(17):5073-83. doi: 10.1021/bi049786u. PMID: 15109266.

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.