Amphiphilic peptide-lipid interaction

Keywords Amphiphilic peptide-lipid interactions Cyclic fS-sheet structure ... 

Facial amphiphilic peptides are another class of facial amphiphiles, which play an important rote in many biological processes involving lipid bilayer membranes. Because of the large surface area of the amphiphilic domains, they are prone to interact with the hydrophiUc/hydrophobic interface of lipid bilayers, which is necessary to assist in membrane fusion or transmembrane pore formation. In the case of pore-forming antibiotics, the peptides are often relatively small (between 25 and 100 amino acids) and the entire peptide becomes facially amphiphilic on folding into the secondary structure. In the case of membrane fusion or curvature-inducing proteins only the peptide fragment, which interacts with the bilayer membrane, is facially amphiphilic. 

Unrelated antimicrobial amphiphilic peptides Peptide-lipid membrane interactions 134... 

Since the first attempt of Chapman and co-workers in 1966 [860], IR spectroscopy has become one of the most frequently used tools for elucidating lipid properties and the mutual effects of different lipids and proteins, which are of interest for different aspects of bioscience and biosensor design (see Refs. [333, 748, 861-864] for review). The IR methods used are transmission, ATR (MIR), and IRRAS for model monolayer, bilayer, and multibilayer membranes and biological membranes. To perform in situ measurements on the membranes of intact individual cells (e.g., as a function of cell membrane potential), planar miniature waveguides can be used instead of the ATR optics [865]. PM-IRRAS has been applied to obtain high-performance spectra of model membranes at the AW interface [866-875]. The experimental data focus mainly on the correlation between the structure of the matrix amphiphile or phospholipid film and the structure of the constituent species, the subphase composition, the surface pressure, and other external conditions, as well as the interaction of such monolayers with peptides and proteins (for reviews, see Refs. [332-334, 876, 877]). 

Studies on synthetic oligomers performed by Aisenbrey et al. provided information on the interaction of N-labelled amphiphilic helices with oriented lipid membranes and revealed the antimicrobial nature of these oligomers. Solid-state NMR helped to characterize the structure, dynamics and membrane topology of antimicrobial polypeptides such as alamethicin or p-hairpin antimicrobials,a novel dendrimeric peptide with antimicrobial potency against Gram-negative bacteria and tachyplesin-1, a disulfide stabilized p-hairpin antimicrobial peptide. 

In addition to amphiphilic alpha helices, peptides with a beta-sheet secondary structure are also known, which are capable of forming transmembrane pores on insertion in lipid bilayers. Although the interaction of beta-sheet type peptides with lipid bilayers operates via many different mechanisms, facial amphiphilicity is one of the key factors for the formation of pores. 

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