Characterization of the boundary zone of a cast protein drop: fibroin beta-sheet and nanofibril formation

Langmuir. 2009 Jun 2;25(11):6307-11. doi: 10.1021/la804308r.

Abstract

We have studied a cast fibroin drop with grazing incidence small-angle X-ray scattering, imaging, and spectroscopy techniques. Optical microscopy shows that the dried drop forms a boundary zone. Grazing-incidence small-angle X-ray scattering performed with a synchrotron radiation microbeam in the boundary zone suggests the formation of nanometer-sized domains with one-dimensional paracrystalline order. Atomic force microscopy and scanning electron microscopy support a nanofibrillar morphology. MicroRaman spectroscopy shows the formation of beta-sheet secondary structure in the boundary zone, which is attributed to a shearing effect due to the retraction of the drop boundary upon evaporation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Fibroins / chemistry*
  • Microscopy, Electron, Scanning
  • Nanostructures / chemistry*
  • Protein Structure, Secondary
  • Spectrum Analysis, Raman
  • Surface Properties

Substances

  • Fibroins