The left-handed Z-DNA form of the short unmodified alternating guanine-cytosine oligonucleotides, 5'-(dGdC)24 and 5'-(dGdC)18, was selectively detected under physiological ionic strength and pH conditions using the anionic nickel(II) porphyrin, NiTPPS. No spectroscopic signal was observed for NiTPPS with any right-handed oligonucleotides under identical conditions. The 48mer 5'-(dGdC)24 Z-form was detected at concentrations as low as 100 nM. The binding of NiTPPS to the B- and Z-oligonucleotides was studied quantitatively by UV-vis absorption and circular dichroism spectroscopies. NiTPPS was found to be a universal DNA binder, with binding affinity and geometry depending on the ionic composition of the solution, rather than on the DNA helical twist. This is the first example of a successful spectroscopic detection of the Z-DNA of short unmodified oligonucleotides under physiological pH and ionic strength conditions.
|Number of pages||4|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 2010 Jun 25|
Bibliographical noteFunding Information:
This research was supported by the University of Wyoming Start-up fund, NCRR and Wyoming INBRE (NIH Grant # P20 RR016474 from the National Center for Research Resources). A.D’U. thanks Universita di Catania. F.N.N. thanks Wyoming INBRE GA (P20RR016474). M.I.L. thanks the University of Wyoming for the College of Arts and Sciences Summer Independent Study Award. M.S.-H. acknowledges the EPSCoR Undergraduate Research Award.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology