Event-averaged measurements of single-molecule kinetics

A modulated N-conformational-channel reactive system is used to model the recent single-molecule enzymatic experiment [Science 282 (1998) 1877]. Kinetic analysis of the model system clearly demonstrates the essential difference between ensemble-averaged bulk measurements associated with the population dynamics of full-reactions and event-averaged single-molecule measurements associated with a sequence of half-reactions. Example calculations of a two-conformational-channel system support the principal findings of the reported experiment. In particular, the observation of the focal time in the single-event distribution function and the echo signal in the two-event distribution function reveals the nature of conformational landscapes.