title: Nonlinear dielectric spectroscopy as an indirect probe of metabolic activity in thylakoid membrane.
abstract: Nonlinear dielectric spectroscopy (NDS) is a non-invasive probe of cellular metabolic activity with potential application in the development of whole-cell biosensors. However, the mechanism of NDS interaction with metabolic membrane proteins is poorly understood, partly due to the inherent complexity of single cell organisms. Here we use the light-activated electron transport chain of spinach thylakoid membrane as a model system to study how NDS interacts with metabolic activity. We find protein modification, as opposed to membrane pump activity, to be the dominant source of NDS signal change in this system. Potential mechanisms for such protein modifications include reactive oxygen species generation and light-activated phosphorylation.
authors.affiliation: Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA. jfang@mail.uh.edu.
authors.forename: Jie
authors.initials: J
authors.lastname: Fang
authors.affiliation: Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA. apalanisami@uh.edu.
authors.forename: Akilan
authors.initials: A
authors.lastname: Palanisami
authors.affiliation: Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA. kirajapa@mail.uh.edu.
authors.forename: Kimal
authors.initials: K
authors.lastname: Rajapakshe
authors.affiliation: Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA. widger@uh.edu.
authors.forename: William R
authors.initials: WR
authors.lastname: Widger
authors.affiliation: Department of Physics and Texas Center for Superconductivity, University of Houston, Houston, TX 77204, USA. jhmiller@uh.edu.
authors.forename: John H
authors.initials: JH
authors.lastname: Miller