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. 1986 Nov;83(22):8462–8466. doi: 10.1073/pnas.83.22.8462

"Footprint" titrations yield valid thermodynamic isotherms.

M Brenowitz, D F Senear, M A Shea, G K Ackers
PMCID: PMC386950  PMID: 3464963

Abstract

A central issue in gene regulation is the mechanism, and biological function, of the cooperative binding of regulatory protein ligands to specific sites on DNA. To elucidate the physical-chemical basis of these interactions we have developed a thermodynamically rigorous method for conducting DNase I "footprint" (protection) titration experiments. The intrinsic binding constants and also those for cooperative interactions between various sites can be resolved from the individual-site binding curves determined by this technique. Experimental studies of cI-repressor-operator binding have demonstrated that the method provides an accurate representation of the fractional saturation of a binding site. We present individual-site binding curves for a lambda operator with two competent sites that demonstrate the presence of cooperative interactions between the sites. These curves set a lower limit to the magnitude of the cooperative free energy without comparison to single-site mutant operators.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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