A rhodium-cyanine fluorescent probe: detection and signaling of mismatches in DNA
We report a bifunctional fluorescent probe that combines a rhodium metalloinsertor with a cyanine dye as the fluorescent reporter. The conjugate shows weak luminescence when free in solution or with well matched DNA but exhibits a significant luminescence increase in the presence of a 27-mer DNA duplex containing a central CC mismatch. DNA photocleavage experiments demonstrate that, upon photoactivation, the conjugate cleaves the DNA backbone specifically near the mismatch site on a 27-mer fragment, consistent with mismatch targeting. Fluorescence titrations with the 27-mer duplex containing the CC mismatch reveal a DNA binding affinity of 3.1 × 10^6 M^(–1), similar to that of other rhodium metalloinsertors. Fluorescence titrations using genomic DNA extracted from various cell lines demonstrate a clear discrimination in fluorescence between those cell lines that are proficient or deficient in mismatch repair. This differential luminescence reflects the sensitive detection of the mismatchrepair-deficient phenotype.
© 2017 American Chemical Society. Received: October 5, 2017; Published: November 14, 2017. We are grateful to the NIH (GM33309) for funding this work. We also thank the Moore Foundation, the Beckman Institute Laser Resource Center facilities, and Dr. Jay R. Winkler for assistance. The authors declare no competing financial interest.
Accepted Version - nihms942611.pdf
Supplemental Material - ja7b10639_si_001.pdf