Telomerase Triggered DNA Walker with a Superhairpin Structure for Human Telomerase Activity Sensing.
Jing HuangLongyi ZhuHuangxian JuJianping LeiPublished in: Analytical chemistry (2019)
Different from conventional DNA walkers, we designed a telomerase-triggered three-dimensional DNA walker consisting of a superhairpin structure with a bulged loop in the stem as the walking strand and dye-labeled tracks for ultrasensitive detection of telomerase activity. In the presence of telomerase, the primers in the stem of the superhairpin structure were elongated and triggered internal strand displacement, thus activating the superhairpin structure. Subsequently, the open superhairpin structure as a swing arm was able to bind with the track, and the swing arm could be released by enzymatic cleavage of the binding duplex domain, resulting in the fluorescence recovery of dye-labeled fragments from the surface of gold nanoparticles. Based on signal amplification of the telomerase-triggered DNA walker, the walking device was further applied to various cancer lines with a low detection limit of telomerase activity equivalent to 90 cells μL-1 for HeLa cells. Moreover, the advantage of this DNA walker strategy was confirmed by calculating telomerase activity in a single cell. This telomerase-triggered DNA walker provides a new concept on signal transduction for telomerase detection and is anticipated to stimulate interest in DNA nanomachine design for bioanalysis.
Keyphrases
- circulating tumor
- single molecule
- cell free
- gold nanoparticles
- nucleic acid
- single cell
- label free
- cell cycle arrest
- endothelial cells
- oxidative stress
- pet imaging
- hydrogen peroxide
- signaling pathway
- real time pcr
- rna seq
- young adults
- mass spectrometry
- induced pluripotent stem cells
- molecularly imprinted
- dna binding
- solid phase extraction