A New Concentration Jump Strategy Reveals the Lifetime of i-Motif at Physiological pH without Force.
Anal Chem
; 90(5): 3205-3210, 2018 03 06.
Article
em En
| MEDLINE
| ID: mdl-29400441
ABSTRACT
Concentration jumps for kinetics measurement remain a challenge for single-molecule techniques, which have demonstrated superior signal-to-noise levels compared to ensemble average approaches. Currently, all concentration jumps use mixing strategies. Here, we report a simple and drastically different jump strategy by rapid transportation of molecules between two side-by-side laminar streams in 80 ms. This allowed us to measure the lifetime of bioactive DNA i-motif structures at physiological pH without force. We placed a human telomeric i-motif inside a DNA hairpin-based mechanical reporter. Since the folded or unfolded state of the hairpin correlates with that of the i-motif, by recording hairpin transitions, a half-life of â¼3 s was found for the DNA i-motif at neutral pH without force. Such a lifetime is sufficient for i-motif to interact with proteins to modulate cellular processes. We anticipate this concentration jump offers a generic platform to investigate single-molecule kinetics.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA
/
Microfluídica
Limite:
Humans
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article