Apolipoprotein A-I-mimetic (4F-P-4F) peptide
Three letter code
Peptide Purity (HPLC)
The 18-amino acid amphipathic helical peptide Ac-DWFKAFYDKVAEKFKEAF-NH(2) 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.
About TFA salt
Trifluoroacetic acid (TFA) is a strong acid, which is commonly used to cleave synthesized peptides from solid-phase resins and is also used to improve HPLC performance in the peptide purification step. By default, custom peptides are delivered as lyophilized TFA salts, and can contain as much as 10-45% TFA.
TFA in custom peptides can cause inexplicable discrepancies in subsequent assay data. For instance, TFA in nM concentrations has been shown to interfere with cellular assays, inhibiting cellular proliferation in some instances, and increasing cell viability in others . It has also been found to be an unintended allosteric modulator of the glycine receptor, GlyR.
TFA Removal Service is recommended for:
- Peptides that will be used in cellular assays
- Peptides that will be used as APIs or in manufactured products
- For hydrophilic peptides containing numerous basic residues
Related Products / Services
• Peptide Services: NovoPro's peptide synthesis services include standard chemical peptide synthesis, peptide modification, peptide libraries, and recombinant peptide expression.
• Standard Peptide Synthesis: NovoPro offers quality peptides at the most competitive prices in the industry, starting at $3.20 per amino acid. NovoPro provides PepBox – Automatic Quote Tool for online price calculation.
• Peptide Modifications: NovoPro offers a wide range of peptide modification services including isotope labeling (2H, 15N, and 13C), multiple disulfide bonds, multiple phosphorylations, KLH, BSA, ovalbumin, amidation, acetylation, biotin, FITC, etc.
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