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bioRxiv · 10.1101/2020.05.12.090639

Designed Anchoring Geometries Determine Lifetimes of Biotin-Streptavidin Bonds under Constant Load and Enable Ultra-Stable Coupling

Gruber, S.·Loef, A.·Sedlak, S.·Benoit, M.·Gaub, H.·Lipfert, J.
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Abstract

The small molecule biotin and the homotetrameric protein streptavidin (SA) form a stable and robust complex that plays a pivotal role in many biotechnological and medical applications. In particular, the biotin-streptavidin linkage is frequently used in single molecule force spectroscopy (SMFS) experiments. Recent data suggest that biotin-streptavidin bonds show strong directional dependence and a broad range of multi-exponential lifetimes under load. Here, we investigate engineered SA variants with different valencies and a unique tethering point under constant forces using a magnetic tweezer assay. We observed two orders-of-magnitude differences in the lifetimes, which we attribute to the distinct force loading geometries in the different SA variants. We identified an especially long-lived tethering geometry that will facilitate ultra-stable SMFS experiments and pave the way for new biotechnological applications.

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Gruber, S., Loef, A., Sedlak, S., Benoit, M., Gaub, H., Lipfert, J.. 2020-05-14. Designed Anchoring Geometries Determine Lifetimes of Biotin-Streptavidin Bonds under Constant Load and Enable Ultra-Stable Coupling. https://doi.org/10.1101/2020.05.12.090639

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