For sample preparation for SEM analysis, the protein coatings formed on a Teflon plate were washed with deionized water and dried under constant flow of nitrogen gas. To image the interface formed between protein coatings and Teflon plate, the sample was cut vertically using a blade. The cross section of the sample was then imaged using SEM. SEM images were taken using a JSM 7800 SEM operated at a 5-kV accelerating voltage. Data are presented in Fig. 4 (B and F) and fig. S8A.