() Normalized fluorescence versus concentration ratio of nucleic acid to protein

Copyright information:Taken from "Nucleic acid binding and chaperone properties of HIV-1 Gag and nucleocapsid proteins"Nucleic Acids Research 2006;34(2):593-605.Published online 30 Jan 2006PMCID:PMC1356529.© The Author 2006. Published by Oxford University Press. All rights reserved Poly(dT) was added to NCp15 (0.5 µM in 1 mM sodium phosphate, pH 7.0, and 25°C). The plateau's intersection with the initial slope indicates the stoichiometry (, occluded binding site size in the case of a polynucleotide) for a titration carried out under near-stoichiometric conditions such as that shown. () Fluorescence recovery (/) after the addition of 5 M NaCl aliquots to a pre-formed NCp15–poly(dT) complex. () Double-logarithmic plot for the association of NCp15 to poly(dT). The slope indicates the number of Na ions displaced; the -intercept is log at 1 M Na, when only non-ionic interactions contribute to binding free energy.