title: Measurement of intracellular pH changes based on DNA-templated capsid protein nanotubes.
abstract: Intracellular pH (pHi) is a fundamental modulator of cell function. Minute changes in pHi may cause great effects in many cellular activities such as metabolism and signal transduction. Herein we report an electrochemical pHi sensor based on viral-coat proteins-DNA nanotubes modified gold electrode. The sensor is pH-sensitive as a result of the pH-dependent electrochemical property of methylene blue (MB) and cell permeable owing to the polyarginine domain of the cowpea chlorotic mottle virus (CCMV) coat protein. Moreover, because the pH sensor can be translocated into cells without any further operations, the measurement of pHi changes can be greatly simplified. The pH sensor has a broad pH spectrum in the pH range from 4.0 to 9.0 and responds rapidly to the pH changes of cells, so it may hold great potential to be a valuable tool to study pH-dependent biological and pathological processes in the future.
authors.affiliation: Department of Biochemistry and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University , 22 Hankou Road, Nanjing 210093, China.
authors.forename: Limin
authors.initials: L
authors.lastname: Ning
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Li
authors.forename: Dawei
authors.initials: D
authors.lastname: Yang
authors.forename: Peng
authors.initials: P
authors.lastname: Miao
authors.forename: Zonghuang
authors.initials: Z
authors.lastname: Ye
authors.forename: Genxi
authors.initials: G
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D017795:Bromovirus / Q000737:chemistry*; D036022:Capsid Proteins / Q000737:chemistry*; D002460:Cell Line; D003593:Cytoplasm / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008751:Methylene Blue / Q000737:chemistry; D008958:Models, Molecular; D043942:Nanotubes / Q000737:chemistry*
chemical_list: D036022:Capsid Proteins; D004247:DNA; D008751:Methylene Blue