铀酰光足迹法

Uranyl photofootprinting.

作者信息

Nielsen Peter E

机构信息

Department of Cellular and Molecular Medicine, University of Copenhagen, The Panum Institute, Blegdamsvej 3c, 2200 Copenhagen N, Denmark.

出版信息

Methods Mol Biol. 2009;543:87-96. doi: 10.1007/978-1-60327-015-1_7.

DOI:10.1007/978-1-60327-015-1_7

PMID:19378161

Abstract

The uranyl-(VI) cation (UO(2) (2+)) forms strong complexes with accessible phosphates of nucleic acid (DNA and RNA) backbones. Upon excitation with long wavelength ultraviolet light (lambda = 300-420 nm), uranyl ions bound to backbone phosphates oxidize proximal sugars and induce nucleic acid backbone cleavage. Thus the uranyl(VI) ion functions as a very specific and efficient photochemical probe for identifying ligand(protein)-phosphate contacts in nucleic acid complexes as well as potential (high affinity) cation (e.g., Mg(2+))-binding sites in folded nucleic acids. Finally, the cleavage modulation of duplex DNA reflects helix conformation in terms of minor groove width, due to preferential affinity/oxidation efficiency for such regions of the DNA helix.

摘要

铀酰（VI）阳离子（UO(2) (2+)）与核酸（DNA和RNA）主链上可及的磷酸盐形成强复合物。在用长波长紫外光（λ = 300 - 420 nm）激发时，与主链磷酸盐结合的铀酰离子会氧化近端糖并诱导核酸主链断裂。因此，铀酰（VI）离子作为一种非常特异且高效的光化学探针，可用于识别核酸复合物中配体（蛋白质） - 磷酸盐接触位点以及折叠核酸中潜在的（高亲和力）阳离子（如Mg(2+)）结合位点。最后，双链DNA的切割调节反映了小沟宽度方面的螺旋构象，这是由于对DNA螺旋此类区域具有优先亲和力/氧化效率。