Single-molecule transport kinetics of a glutamate transporter homolog shows static disorder
| Autor: | Scott C. Blanchard, Olga Boudker, Changhao He, Gabriel A. Fitzgerald, Zhou Zhou, Didar Ciftci, Gerard H. M. Huysmans, Daniel S. Terry, Xiaoyu Wang |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0303 health sciences
education.field_of_study Multidisciplinary biology Chemistry Mutant Kinetics Population Biophysics SciAdv r-articles Transporter Periplasmic space biology.organism_classification 03 medical and health sciences Pyrococcus horikoshii 0302 clinical medicine Förster resonance energy transfer Amino acid binding education Molecular Biology 030217 neurology & neurosurgery Research Articles 030304 developmental biology Research Article |
| Zdroj: | Science Advances |
| ISSN: | 2375-2548 |
| Popis: | Single-molecule detection of transport turnovers shows a distribution of rates with fast transporters favored by mutations. Kinetic properties of membrane transporters are typically poorly defined because high-resolution functional assays analogous to single-channel recordings are lacking. Here, we measure single-molecule transport kinetics of a glutamate transporter homolog from Pyrococcus horikoshii, GltPh, using fluorescently labeled periplasmic amino acid binding protein as a fluorescence resonance energy transfer–based sensor. We show that individual transporters can function at rates varying by at least two orders of magnitude that persist for multiple turnovers. A gain-of-function mutant shows increased population of the fast-acting transporters, leading to a 10-fold increase in the mean transport rate. These findings, which are broadly consistent with earlier single-molecule measurements of GltPh conformational dynamics, suggest that GltPh transport is defined by kinetically distinct populations that exhibit long-lasting “molecular memory.” |
| Databáze: | OpenAIRE |
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