Label-free luminescent switch-on detection of endonuclease IV activity using a G-quadruplex-selective iridium(III) complex.
We report herein the synthesis and application of a novel G-quadruplex-selective luminescent iridium(III) complex [Ir(ppy)2(bcp)](+) (where ppy = 2-phenylpyridine and bcp = 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) for the sensitive detection of apurinic/apyrimidinic (AP) endonuclease activity. Using endonuclease IV (Endo IV) as a model enzyme, a duplex DNA substrate containing a G-quadruplex-forming sequence is cleaved by Endo IV at the abasic site. This releases the G-quadruplex sequence, which folds into a G-quadruplex and is recognised by the G-quadruplex-selective iridium(III) complex with an enhanced luminescence response. The assay achieved high sensitivity and selectivity for Endo IV over other tested enzymes.
Department of Chemistry, Hong Kong Baptist University , Kowloon Tong, Hong Kong, China.
Ka-Ho
KH
Leung
Hong-Zhang
HZ
He
Wei
W
Wang
Hai-Jing
HJ
Zhong
Daniel Shiu-Hin
DS
Chan
Chung-Hang
CH
Leung
Dik-Lung
DL
Ma
D004277:DNA, Single-Stranded / Q000737:chemistry; D043223:Deoxyribonuclease IV (Phage T4-Induced) / Q000378:metabolism*; D054856:G-Quadruplexes; D007495:Iridium / Q000737:chemistry*; D049449:Luminescence
D004277:DNA, Single-Stranded; D007495:Iridium; D043223:Deoxyribonuclease IV (Phage T4-Induced)