Single-molecule Michaelis-Menten kinetics: Effect of substrate fluctuations

In this work we have simulated a stochastic model of single-molecule enzymatic kinetics and applied several statistics to find whether substrate fluctuations can cause significant deviations from the standard single-molecule Michaelis-Menten kinetics. We have found that substrate fluctuations can be detected under favorable conditions (i.e. for fast irreversible binding) when long turnover time trajectories are analyzed. However, for reversible and/or slow intrinsic binding substrate fluctuations may be difficult to observe experimentally.