title: [Ru(Me4phen)2dppz](2+), a Light Switch for DNA Mismatches.
abstract: [Ru(Me4phen)2dppz](2+) serves as a luminescent "light switch" for single base mismatches in DNA. The preferential luminescence enhancement observed with mismatches results from two factors: (i) the complex possesses a 26-fold higher binding affinity toward the mismatch compared to well-matched base pairs, and (ii) the excited state emission lifetime of the ruthenium bound to the DNA mismatch is 160 ns versus 35 ns when bound to a matched site. Results indicate that the complex binds to the mismatch through a metalloinsertion binding mode. Cu(phen)2(2+) quenching experiments show that the complex binds to the mismatch from the minor groove, characteristic of metalloinsertion. Additionally, the luminescence intensity of the complex with DNA containing single base mismatches correlates with the thermodynamic destabilization of the mismatch, also consistent with binding through metalloinsertion. This complex represents a potentially new early cancer diagnostic for detecting deficiencies in mismatch repair.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Adam N
authors.initials: AN
authors.lastname: Boynton
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Lionel
authors.initials: L
authors.lastname: Marcélis
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Jacqueline K
authors.initials: JK
authors.lastname: Barton
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D053843:DNA Mismatch Repair; D007700:Kinetics; D049449:Luminescence; D009942:Organometallic Compounds / Q000737:chemistry*; D010619:Phenazines / Q000737:chemistry*; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D009942:Organometallic Compounds; D010619:Phenazines; C077849:bis(2,2'-bipyridyl)(dipyrido(3,2-alpha-2',3'-c)phenazine)ruthenium (II); D004247:DNA