title: Surfactant-induced assembly of enzymatically-stable peptide hydrogels.
abstract: The secondary structure of peptides in the presence of interacting additives is an important topic of study, having implications in the application of peptide science to a broad range of modern technologies. Surfactants constitute a class of biologically relevant compounds that are known to influence both peptide conformation and aggregation or assembly. We have characterized the secondary structure of a linear nonapeptide composed of a hydrophobic alanine/phenylalanine core flanked by hydrophilic acid/amine units. We show that the anionic surfactant sodium dodecyl sulfate (SDS) induces the formation of β-sheets and macroscopic gelation in this otherwise unstructured peptide. Through comparison to related additives, we propose that SDS-induced secondary structure formation is the result of amphiphilicity created by electrostatic binding of SDS to the peptide. In addition, we demonstrate a novel utility of surfactants in manipulating and stabilizing peptide nanostructures. SDS is used to simultaneously induce secondary structure in a peptide and to inhibit the activity of a model enzyme, resulting in a peptide hydrogel that is impervious to enzymatic degradation. These results complement our understanding of the behavior of peptides in the presence of interacting secondary molecules and provide new potential pathways for programmable organization of peptides by the addition of such components.
authors: Sandia National Laboratories, Electronic, Optical, and Nano Materials, PO Box 5800, MS 1411, Albuquerque, NM 87185, USA. edspoer@sandia.gov.
authors: Brad H
authors: BH
authors: Jones
authors: Alina M
authors: AM
authors: Martinez
authors: Jill S
authors: JS
authors: Wheeler
authors: Erik D
authors: ED
authors: Spoerke
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D020100:Hydrogels / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012212:Rheology; D053838:Scattering, Small Angle; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D020100:Hydrogels; D010455:Peptides; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate