Fast-scanning AFM is now applicable to the analyses of single-molecule reactions in nano-biophysics

Atomic force microscopy (AFM) has been used to visualize nano-scale structures of DNA, proteins and higher-order structures of DNA/protein complexes, such as chromatin and chromosome. Recently, there has been remarkable progress to visualize reaction dynamics at a single molecular level in real time and to measure a single molecular kinetics by using newly developed fast-scanning AFM. In this paper, we addressed these recent applications of fast-scanning AFM technology. With this novel technology, we succeeded to visualize the DNA cleavage reaction by a type IIP restriction endonuclease Apal and to kinetically analyze the chaperonin (GroEL) cochaperonin (GroES) at a single molecular level. Thus, the fast-scanning AFM is powerful to understand protein structures and dynamics in biological reactions at the single molecule level in sub-seconds