Figure 3.

Collection of force curves of [C(KAAAA)₁₀KC]_n obtained under different conditions. (A) Collection of various types of force curves. (a) In 50 mM Tris buffer, pH 7.4: force curve without any indication of adhesion. (b) With a plateau like adhesion. (c) With initial strong adhesion, followed by extension of a plateau. (d) Obtained in 50 mM Tris buffer, pH 7.4, with 400 mM NaCl. (e) 50 mM Tris buffer, pH 7.4, with 50% TFE. (f) 50 mM Tris buffer, pH 7.4, with 6 M GdmCl. Parts of curves marked by dotted circles highlight gradual change of slope, as explained in text. (B) Record of approach and retraction cycles obtained in 50% TFE, showing reversibility of the conformational change of the sample polypeptide.