Fundamental design principles that guide induction of helix upon formation of stable peptide-nanoparticle complexes.
We have shown that it is possible to design a peptide that has a very low helical content when free in solution but that adopts a well-defined helix when interacting with silica nanoparticles. From a systematic variation of the amino acid composition and distribution in designed peptides, it has been shown that the ability to form helical structure upon binding to the silica surface is dominated by two factors. First, the helical content is strongly correlated with the net positive charge on the side of the helix that interacts with the silica, and arginine residues are strongly favored over lysine residues in these positions. The second important factor is to have a high net negative charge on the side of the helix that faces the solution. Apparently, both attractive and repulsive electrostatic forces dominate the induction and stabilization of a bound helix. It is also evident that using amino acids that have high propensity to form helix in solution are also advantageous for the formation of helix on surfaces.
Nygren
Patrik
P
Division of Applied Physics, IFM, and Division of Molecular Biotechnology, Linköping University, SE-581 83 Linköping, Sweden.
Lundqvist
Martin
M
Broo
Klas
K
Jonsson
Bengt-Harald
BH
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012822:Silicon Dioxide / Q000737:chemistry; D017186:Titrimetry
D010455:Peptides; D012822:Silicon Dioxide