A Method for Assessing Kinetic Changes of Histone H1 after Post-Translational Modifications

Fluorescence Recovery After Photobleaching (FRAP) has become one of the main fluorescence microscopy techniques used to measure motion and interaction of nuclear proteins. In this work, we propose a mathematical method for analyzing sets of FRAP data to assess the effect of post-translational modifications on the binding affinities of histone H1 proteins. The method is based on a model that accounts for weakly and strongly bound populations and comprises the estimation of kinetic parameters before and after post-translational modifications and the use of non-parametric statistics to analyze changes in the estimated parameters. The procedure is illustrated with sets of FRAP data of histone H1 binding to hyperacetylated chromatin.