Binding properties of Ru(II) polypyridyl complexes with poly(U)center dot poly(A)*poly(U) triplex: the ancillary ligand effect on third-strand stabilization

作者：Tan, Li Feng^*; Xie, Ling Jun; Sun, Xiao Nan

来源：Journal of Biological Inorganic Chemistry, 2013, 18(1): 71-80.

DOI：10.1007/s00775-012-0950-8

• Ru(II) polypyridyl complexes
• Lowest unoccupied molecular orbital energy
• Binding properties
• Triplex RNA stabilization

The binding properties of [RuL2(mip)](2+) {where L is 1,10-phenanthroline (phen) or 4,7-dimethyl-1,10-phenanthrollne (4,7-dmp) and mip is 2'-(3aEuro(3),4aEuro(3)-methylenedioxyphenyl)imidazo[4',5'-f][1,10]phenanthroline} with regard to the triplex RNA poly(U)center dot poly(A)*poly(U) were investigated using various biophysical techniques and quantum chemistry calculations. In comparison with [Ru(4,7-dmp)(2)(mip)](2+), remarkably higher binding affinity of [Ru(phen)(2)(mip)](2+) for the triplex RNA poly(U)center dot poly(A)*poly(U) was achieved by changing the ancillary ligands. The stabilization of the Hoogsteen-base-paired third strand was improved by about 10.9 A degrees C by [Ru(phen)(2)(mip)](2+) against 6.6 A degrees C by [Ru(4,7-dmp)(2)(mip)](2+). To the best of our knowledge, [Ru(phen)(2)(mip)](2+) is the first metal complex able to raise the third-strand stabilization of poly(U)center dot poly(A)*poly(U) from 37.5 to 48.4 A degrees C. The results reveal that the ancillary ligands have an important effect on third-strand stabilization of the triplex RNA poly(U)center dot poly(A)*poly(U) when metal complexes contain the same intercalative ligands.

• 出版日期2013-1
• 单位湘潭大学