Molecular images of cereal proteins by STM.

Scanning tunnelling microscopy (STM) has been used to study a seed storage protein of wheat known as gamma-gliadin. The protein was deposited onto highly oriented pyrolytic graphite (HOPG) from solutions of trifluoroethanol (TFE) and 1% acetic acid. Samples were dried down and then scanned in air. Transmission electron microscopy (TEM) was also used to visualise the distribution of protein on the substrate. Small-angle X-ray scattering (SAXS) was used to compare the molecular size and shape obtained with those from the STM images.