REACTIONS OF FLUORESCAMINE WITH CHROMOSOMAL-PROTEINS

α- and ε-amino groups of basic chromosomal proteins (protamines and histones) are available for the reaction with fluorescamine. The extent of the reaction depends on the respective pKa values but linear relationships between the protein concentration and fluorescence were found at all pH values tested (5.5-10.5). Upon interaction with DNA, the pKa values of protein amino groups are raised to an extent which excludes them from the fluorescamine reaction under quasiphysiological conditions. Protein displacements caused by dissociating agents may conveniently be followed kinetically and can be quantified by appropriate applications of fluorescamine. © 1979 Academic Press, Inc.