ABSTRACT
Enzymes are complex molecular machines. They break down
catalytic reactions into several substeps, often involving different
conformations. These different conformations are a direct conse-
quence of the multidimensional energy landscape of the enzymes.
The energy landscape further determines regulation processes and
might further allow parallel reaction pathways. Information about
the kinetics of multistep reactions, regulation events, and parallel
reaction pathways is intrinsically difficult to obtain in ensemble
measurements. Single-molecule experiments are perfectly designed
for studying these processes. They not only provide the possibility
for observing an enzyme individually but also, more importantly,
allow for following the enzymatic reaction in real time, directly
yielding the sequence of events.
