Classic Analysis of Biopolymer Dynamics Is Model Free.

Early analysis of biopolymer dynamics relied on a variety of motional models that were difficult to distinguish and sometimes gave contradictory results. The Lipari-Szabo model-free approach (documented in a 1980 article in Biophysical Journal, as well as in two more comprehensive 1982 articles in the Journal of the American Chemical Society, provided a simple formalism that allowed investigators to understand fluorescence and NMR experimental data without having to specify a motional model. Although the model-free method is not universally applicable (for example, its assumption of a uniform correlation time for overall molecular tumbling can be problematic for biomolecules containing areas of disorder), it remains the most popular and widely used technique for analyzing molecular motion.