TY - JOUR
T1 - A New Concentration Jump Strategy Reveals the Lifetime of i-Motif at Physiological pH without Force
AU - Jonchhe, Sagun
AU - Shrestha, Prakash
AU - Ascencio, Katia
AU - Mao, Hanbin
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/3/6
Y1 - 2018/3/6
N2 - 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 ∼3 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.
AB - 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 ∼3 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.
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U2 - 10.1021/acs.analchem.7b04661
DO - 10.1021/acs.analchem.7b04661
M3 - Article
C2 - 29400441
AN - SCOPUS:85043236761
SN - 0003-2700
VL - 90
SP - 3205
EP - 3210
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 5
ER -