The high-energy transition state of a membrane transporter
| Autor: | Xiaoyu Wang, Olga Boudker, Scott C. Blanchard, Didar Ciftci, Gerard H. M. Huysmans |
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| Rok vydání: | 2020 |
| Předmět: |
0303 health sciences
Cell signaling Fluorescence-lifetime imaging microscopy Chemistry Allosteric regulation Mutant Transporter Quantitative Biology::Cell Behavior Quantitative Biology::Subcellular Processes 03 medical and health sciences 0302 clinical medicine Membrane Cytoplasm Extracellular Biophysics 030217 neurology & neurosurgery 030304 developmental biology |
| Popis: | Membrane transporters mediate cellular uptake of nutrients, signaling molecules and drugs. Their overall mechanisms are often well understood, but the structural features setting their rates are mostly unknown. Earlier single-molecule fluorescence imaging of a model glutamate transporter homologue suggested that the slow conformational transition from the outward- to the inward-facing state, when the bound substrate is translocated from the extracellular to the cytoplasmic side of the membrane, is rate-limiting to transport. Here, we aim to gain insight into the structure of the high-energy transition state that limits the rate of this critical isomerization reaction. Using bioinformatics, we identify gain-of-function mutants of the transporter and apply linear free energy relationship analysis to infer that the transition state structurally resembles the inward-facing conformation. Based on these analyses, we propose an approach for allosteric modulation of these transporters. |
| Databáze: | OpenAIRE |
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