A Dual‐Response DNA Probe for Simultaneously Monitoring Enzymatic Activity and Environmental pH Using a Nanopore

• Published in: Angewandte Chemie International Edition Vol. 58; no. 42; pp. 14929 - 14934
• Main Authors: Liu, Lei, You, Yi, Zhou, Ke, Guo, Bingyuan, Cao, Zhong, Zhao, Yuliang, Wu, Hai‐Chen
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 14.10.2019
• Edition: International ed. in English
• Subjects: Complex systems; Deoxyribonucleic acid; DNA; DNA probe; Environmental monitoring; Enzymatic activity; host–guest systems; nanopore; Peptides; pH effects; Phenylalanine; Porosity; Protease; Proteinase; Signatures; simultaneous quantification; single-molecule studies; Translocation; simultaneous quantification; host-guest systems; nanopore; DNA probe; single-molecule studies
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201907816

Both protease overexpression and local pH changes are key signatures of cancer. However, the sensitive detection of protease activities and the accurate measurement of pH in a tumor environment remain challenging. Here, we develop a dual‐response DNA probe that can simultaneously monitor protease activities and measure the local pH by translocation through α‐hemolysin (αHL). The DNA probe bears a short peptide containing phenylalanine at a pre‐designed position. Enzymatic cleavage of the peptide either exposes or removes the N‐terminal phenylalanine that can form a complex with cucurbit[7]uril. Translocation of the DNA hybrid through αHL generates current signatures that can be used to quantify protease activities. Furthermore, the current signatures possess a pH‐dependent pattern that reflects the local pH. Our results demonstrate that the versatile DNA probe may be further explored for simultaneously measuring multiple parameters of a complex system such as single cells in the future. Two functions in one nanopore: Enzymatic cleavage of a peptide on a DNA probe either exposes or removes an N‐terminal phenylalanine that can form a complex with cucurbit[7]uril. Translocation of the DNA hybrid through the α‐hemolysin nanopore generates current signatures that can be used to quantify protease activity. The current signature also reflects the pH of the environment.