Issue 17, 2020

Multifunctional streptavidin–biotin conjugates with precise stoichiometries


Streptavidin is ubiquitously used to link different biotinylated molecules thanks to its tetravalent binding to biotin. An unwanted side-effect is the resulting statistical mixtures of products. Here, a general approach to form multifunctional streptavidin conjugates with precise stoichiometries and number of open binding pockets is reported. This method relies on an iminobiotin-polyhistidine tag, which allows separating streptavidin conjugates with different numbers of tags, and later reopening binding pockets at lowered pH to introduce a second functionality. Pure fluorescently labelled mono-, di- and trivalent streptavidin–biotin conjugates prepared in this way were used for imaging biotinylated cell surface molecules with controlled clustering. Furthermore, these conjugates were functionalized with a second biotinylated molecule, folic acid–biotin, to investigate the importance of multivalent binding in targeted delivery of cancer cells. These streptavidin–biotin conjugates with precise stoichiometries combined with a variety of biotinylated molecules render this method a diverse and powerful tool for molecular biology and biotechnology.

Graphical abstract: Multifunctional streptavidin–biotin conjugates with precise stoichiometries

Supplementary files

Article information

Article type
Edge Article
17 Mar 2020
10 Apr 2020
First published
20 Apr 2020
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2020,11, 4422-4429

Multifunctional streptavidin–biotin conjugates with precise stoichiometries

D. Xu and S. V. Wegner, Chem. Sci., 2020, 11, 4422 DOI: 10.1039/D0SC01589J

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