Binding and Dissociation Kinetics of Wild-Type and Mutant Streptavidins on Mixed Biotin-Containing Alkylthiolate Monolayers
| Autor: | and P. S. Stayton, Kjell E. Nelson, Linda S. Jung, Charles T. Campbell |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Langmuir. 16:9421-9432 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la000144r |
| Popis: | The kinetics of adsorption and competitive desorption of wild-type streptavidin (WT SA) and three genetically engineered mutants (S27A, N23E, and W120A) was studied at gold surfaces functionalized with mixed alkylthiolates, some terminated with biotin headgroups and the rest with oligo(ethylene oxide) using surface plasmon resonance (SPR). The saturation coverage of the protein varied strongly with surface biotin concentration (XBAT) and was independent of mutation (except at very low and very high XBAT, where a weak dependence was seen). Initial adsorption rates were nearly diffusion-limited except at extremely low XBAT, where the rate varied weakly between mutants in accordance with their differing strengths of binding to biotin. Initial sticking probabilities were estimated to be between ∼1−6 × 10-6 per collision with the surface. The adsorbed SA desorbs upon introduction of solution-phase biotin. For XBAT below 1%, the desorption rate constants of the SA variants closely follow their off-rate constant... |
| Databáze: | OpenAIRE |
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