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Cellular & Molecular Biology Letters

Open Access

Statistical properties of the dichotomous noise generated in biochemical processes

Cellular & Molecular Biology LettersAn International Journal200813:502

Received: 26 September 2007

Accepted: 12 February 2008

Published: 5 May 2008


Dichotomous noise detected with the help of various single-molecule techniques convincingly reveals the actual occurrence of a multitude of conformational substates composing the native state of proteins. The nature of the stochastic dynamics of transitions between these substates is determined by the particular statistical properties of the noise observed. These involve nonexponential and possibly oscillatory time decay of the second order autocorrelation function, its relation to the third order autocorrelation function, and a relationship to dwell-time distribution densities and their correlations. Processes gated by specific conformational substates are distinguished from those with fluctuating barriers. This study throws light on the intriguing matter of the possibility of multiple stepping of the myosin motor along the actin filament per ATP molecule hydrolyzed.

Key words

Single-molecule techniquesTime autocorrelation functionsDwell-time distribution densitiesMolecular gear