title: Effects of electrospinning and solution casting protocols on the secondary structure of a genetically engineered dragline spider silk analogue investigated via Fourier transform Raman spectroscopy.
abstract: Micrometer and submicrometer diameter fibers of recombinant dragline spider silk analogues, synthesized via protein engineering strategies, have been electrospun from 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and compared with cast films via Raman spectroscopy in order to assess changes in protein conformation that may result from the electrospinning process. Although the solvent casting process was shown to result in predominantly beta-sheet conformation similar to that observed in the bulk, the electrospinning process causes a major change in conformation from beta-sheet to alpha-helix. A possible mechanism involving electric field-induced stabilization of alpha-helical segments in HFIP solution during the electrospinning process is discussed.
authors.affiliation: Department of Materials Science and Engineering and Delaware Biotechnology Institute, University of Delaware, Newark, Delaware 19716, USA. jean.stephens@nist.gov
authors.forename: Jean S
authors.initials: JS
authors.lastname: Stephens
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Fahnestock
authors.forename: Robin S
authors.initials: RS
authors.lastname: Farmer
authors.forename: Kristi L
authors.initials: KL
authors.lastname: Kiick
authors.forename: D Bruce
authors.initials: DB
authors.lastname: Chase
authors.forename: John F
authors.initials: JF
authors.lastname: Rabolt
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D005349:Fibroins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D019476:Insect Proteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D015202:Protein Engineering / Q000379:methods*; D017433:Protein Structure, Secondary / Q000235:genetics; D047011:Silk / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D019476:Insect Proteins; D047011:Silk; C086087:spidroin 1; C076815:spidroin 2; D005349:Fibroins