Figure 25.

HS-AFM imaging of SERCA dynamics in the presence of nucleotide and Ca²⁺. (a) Successive HS-AFM images in the presence of 10 nM ATP and 100 μM free Ca²⁺ captured at a frame rate of 1 fps. The cross sections along the X- and Y-axes are shown in the corresponding lower panels. The broken line indicates a height of 5.5 nm from the membrane surface. (b,c) Single line scan (2D observation) HS-AFM images of SERCA in the presence of 100 μm free Ca²⁺ and in the presence of (b) 10 nM and (c) 1 μM ATP, respectively. The lower panels show the X-axis cross sections positioned at the line indicated by the arrow beside the 2D HS-AFM images. Reprinted with permission from ref (49). Copyright 2011 John Wiley & Sons, Inc.