Barrel-stave model

Barrel-stave model Model for pore-forming amphipathic peptides in which the polar face forms a hydrophilic pore. 

Yang, L., Harroun, T. A., et al. (2001). Barrel-stave model or toroidal model A case study on melittin pores. Biophysical Journal, 81(5), 1475-1485. 

Figure 21 Natural crown ethers and biomimetic crown ethers (a) nonactin (b) valinomycin (c) a barrel-stave model (d) a hydraphile. " ...

Figure 12 Mechanism of proposed pore formation by amphiphilic alpha heUces. (a) Single hehces combine with the bilayer, (b) K the concentration monomer is sufficient, the monomers insrat in the hydrophobic core and align via the barrel-stave model or (c) via the toroidal model. (Reproduced from Ref. 57. John WUey Sons, Ltd, 2000.)...

An example of pore-forming alpha helix acting via the barrel-stave models is the toxin pardaxin. This 33-residue peptide is found in the Red Sea Moses sole (a flatfish) and nsed to repel Sharks. It is found that this peptide binds to bilayer snrfaces and forms transmembrane pores consisting of 6 3 peptides. Remarkable is the efficiency... 

A second model, referred to as the toroidal model, is fairly similar to the barrel-stave model for the first step. The toroidal model differs from the barrel-stave model in that the peptides are associated with the lipid head groups and stay bound to these head groups through the entire process, even when they are perpendicularly inserted in the lipid bilayer (Figure 12c). It has been suggested that the previously discussed magainin 2 forms transmembrane pores via the toroidal model and only four to seven peptides can form a transmembrane pores at Upidipeptide ratios of 100 ... 

BEssiN Y, SAINT N, MARRi L, MARCHiNi D, MOLLE G. Antibacterial activity and pore-forming properties of ceratotoxins a mechanism of action based on the barrel stave model. Biochim Biophys Acta 2004 Dec 15 1667(2) 148-56. 

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