| Autor: |
Gerhard Baaken, Marcel Hoffmann, Anne-Katrin Schuler, Jan C. Behrends |
| Jazyk: |
angličtina |
| Předmět: |
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| Zdroj: |
Biophysical Journal. (2):212a |
| ISSN: |
0006-3495 |
| DOI: |
10.1016/j.bpj.2013.11.1246 |
| Popis: |
Alpha-hemolysin nanopores are used to detect single oligomers of poly(ethyleneglycol) (PEG) which under high salt conditions reside in the pore for extended periods of time (up to several ms) suggesting binding to the pore's inner wall. We study the interaction of two species of PEG of degree of polymerization 28 and 32 which, following sequential entry, simultaneously reside in the pore. This doubly occupied (DO) state can result in direct replacement of the first occupant by the second. Analyzing the dwell times of the DO states, we ask whether binding as a first or second pore occupant is equivalent in terms of stability. We find that the DO state lifetimes are shorter than would be predicted by simple superposition (see Figure). We conclude that binding in the pore as the second occupant is highly unstable, suggesting that the more stable primary binding state cannot be attained by more than one PEG molecule. The doubly occupied state thus represents an intermediate state with possible general relevance for competitive interactions at binding sites to which access is gained through long channels, such as in some enzymes.View Large Image | View Hi-Res Image | Download PowerPoint Slide |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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