DNA labelling topologies for monitoring DNA-protein complex formation by fluorescence anisotropy.

In this work, fluorescence anisotropy was used to study DNA binding of the DNA methyltransferase M.TaqI. For this purpose short DNA molecules labelled with three different fluorophores (Cy3, thiazole orange, and ethidium bromide) were prepared in various topologies and their suitability for detection of DNA-protein complex formation was investigated.

Pyrene-modified guanosine as fluorescent probe for DNA modulated by charge transfer.

8-(Pyren-1-yl)-2'-deoxyguanosine (Py-G) was incorporated synthetically as a modified DNA base and optical probe into oligonucleotides. A variety of Py-G-modified DNA duplexes have been investigated by methods of optical spectroscopy. The DNA duplex hybridization can be observed by both fluorescence and absorption spectroscopy since the Py-G group exhibits altered properties in single strands versus double strands for both spectroscopy methods.

Base pair motions control the rates and distance dependencies of reductive and oxidative DNA charge transfer.

In 1999, Wan et al. [Proc. Natl.

8-(Pyren-1-yl)-2'-deoxyguanosine as an optical probe for DNA hybridization and for charge transfer with small peptides.

8-(Pyren-1-yl)-2'-deoxyguanosine (Py-G) was incorporated synthetically as an optical probe into oligonucleotides. The Py-G group in DNA does not discriminate between any of the four natural nucleosides as a counterbase and exhibits altered optical properties in single strands versus double strands. Thus, the duplex hybridization of Py-G-modified DNA can be observed by both fluorescence and absorption spectroscopy.

Detection of single base mismatches and abasic sites using phenanthridinium as an artificial DNA base and charge donor.

Combining the fluorescence properties of phenanthridinium as an artificial DNA base together with DNA-mediated charge transfer processes allows the homogeneous detection of DNA base mismatches and abasic sites.