title: Tethered spectroscopic probes estimate dynamic distances with subnanometer resolution in voltage-dependent potassium channels.
abstract: Measurements of inter- and intramolecular distances are important for monitoring structural changes and understanding protein interaction networks. Fluorescence resonance energy transfer and functionalized chemical spacers are the two predominantly used strategies to map short-range distances in living cells. Here, we describe the development of a hybrid approach that combines the key advantages of spectroscopic and chemical methods to estimate dynamic distance information from labeled proteins. Bifunctional spectroscopic probes were designed to make use of adaptable-anchor and length-varied spacers to estimate molecular distances by exploiting short-range collisional electron transfer. The spacers were calibrated using labeled polyproline peptides of defined lengths and validated by molecular simulations. This approach was extended to estimate distance restraints that enable us to evaluate the resting-state model of the Shaker potassium channel.
authors.affiliation: Department of Neuroscience, University of Wisconsin, Madison, Wisconsin.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Jarecki
authors.affiliation: School of Pharmacy, Division of Pharmaceutical Sciences, University of Wisconsin, Madison, Wisconsin.
authors.forename: Suqing
authors.initials: S
authors.lastname: Zheng
authors.affiliation: Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Wisconsin.
authors.forename: Leili
authors.initials: L
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Division of Pharmaceutical Sciences, University of Wisconsin, Madison, Wisconsin.
authors.forename: Xiaoxun
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Pharmacy, Division of Pharmaceutical Sciences, University of Wisconsin, Madison, Wisconsin.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Wisconsin.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Cui
authors.affiliation: School of Pharmacy, Division of Pharmaceutical Sciences, University of Wisconsin, Madison, Wisconsin.
authors.forename: Weiping
authors.initials: W
authors.lastname: Tang
authors.affiliation: Department of Neuroscience, University of Wisconsin, Madison, Wisconsin. Electronic address: chanda@wisc.edu.
authors.forename: Baron
authors.initials: B
authors.lastname: Chanda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D031541:Fluorescence Resonance Energy Transfer; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D009154:Mutation; D051637:Shaker Superfamily of Potassium Channels / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014981:Xenopus
chemical_list: D051637:Shaker Superfamily of Potassium Channels