Kinetics: Single-Molecule Techniques
Living reference work entry
Although single molecules have been imaged by electron microscopy for many years, their detection by optical methods since the 1990s has allowed their kinetic, as well as structural, properties to be investigated (Makarov 2015; Weiss 2000). This advance has given new insights into mechanism by revealing details that are masked by traditional ensemble measurements. Furthermore, there is no need to initiate the reaction by mixing or perturbing the environment because an individual molecule can be observed as it spontaneously switches between states under equilibrium or steady-state conditions (Stone et al. 2007). This approach also has good dynamic range; for example, if a molecule exists in a particular state for just 1% of its time, on average, then it may readily be observed at the single-molecule level but masked at the ensemble level because of the contribution of 99% of molecules in other states. However, technical challenges remain...
Single-turnover assay of Cy3-EDA-ATP by skeletal muscle myosin subfragment 1 (MPG 6376 kb)
© European Biophysical Societies' Association (EBSA) 2018