Correlated trapping of sugar molecules by the trimeric protein channel chitoporin
| Autor: | Wipa Suginta, M. F. Smith, Mathias Winterhalter |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Passive transport Carbohydrates Biophysics Porins Sequence (biology) Trapping 01 natural sciences Biochemistry 03 medical and health sciences chemistry.chemical_compound 0103 physical sciences Kinetic isotope effect Molecule 010306 general physics Sugar Cell Biology Deuterium Crystallography 030104 developmental biology Monomer chemistry Chemical physics Protein Multimerization Bacterial Outer Membrane Proteins |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. 1858:3032-3040 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/j.bbamem.2016.09.007 |
| Popis: | The protein channel chitoporin (ChiP), which is used by marine bacteria to translocate selected sugar molecules through the outer cell membrane, is studied via single channel current measurements in water and heavy water sugar solutions. The dynamic trapping and escape probabilities of sugar molecules from different monomers in the trimeric channel are characterized, including their dependence on channel orientation and sensitivity to a deuterium isotope effect. A detailed analysis of stochastic current fluctuations reveals that the trapping properties of chitoporin exhibit memory effects: the rate of trapping transitions depends on the previous sequence of transitions; and intermonomer correlations: the average trapping rate of an unblocked monomer is larger when its neighboring monomers are blocked. The latter, likely resulting from rapid re-trapping of recently escaped sugar molecules, is considered as a possible design strategy to enhance sugar transport. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect