Selection Criteria: Structures within a prefixed threshold of amber energy, solvent accessible surface area and symmetry-based penalty functions (see jrnl) 
Primary Citation of Related Structures:   1XKM
PubMed Abstract: 
Many bioactive peptides, presenting an unstructured conformation in aqueous solution, are made resistant to degradation by posttranslational modifications. Here, we describe how molecular oligomerization in aqueous solution can generate a still unknown transport form for amphipathic peptides, which is more compact and resistant to proteases than forms related to any possible monomer ...
Many bioactive peptides, presenting an unstructured conformation in aqueous solution, are made resistant to degradation by posttranslational modifications. Here, we describe how molecular oligomerization in aqueous solution can generate a still unknown transport form for amphipathic peptides, which is more compact and resistant to proteases than forms related to any possible monomer. This phenomenon emerged from 3D structure, function, and degradation properties of distinctin, a heterodimeric antimicrobial compound consisting of two peptide chains linked by a disulfide bond. After homodimerization in water, this peptide exhibited a fold consisting of a symmetrical full-parallel four-helix bundle, with a well secluded hydrophobic core and exposed basic residues. This fold significantly stabilizes distinctin against proteases compared with other linear amphipathic peptides, without affecting its antimicrobial, hemolytic, and ion-channel formation properties after membrane interaction. This full-parallel helical orientation represents a perfect compromise between formation of a stable structure in water and requirement of a drastic structural rearrangement in membranes to elicit antimicrobial potential. Thus, distinctin can be claimed as a prototype of a previously unrecognized class of antimicrobial derivatives. These results suggest a critical revision of the role of peptide oligomerization whenever solubility or resistance to proteases is known to affect biological properties.
Related Citations: 
A novel heterodimeric antimicrobial peptide from the tree-frog Phyllomedusa distincta Batista, C.V., Scaloni, A., Rigden, D.J., Silva, L.R., Rodrigues Romero, A., Dukor, R., Sebben, A., Talamo, F., Bloch, C. (2001) FEBS Lett 494: 85
Organizational Affiliation: 
Institute of Biomolecular Chemistry, National Research Council, Comprensorio Olivetti, Edificio 70, I-80078 Pozzuoli (Naples), Italy.
Selection Criteria: Structures within a prefixed threshold of amber energy, solvent accessible surface area and symmetry-based penalty functions (see jrnl)