Streptavidin interaction with biotin

Lee G U, Kidwell D A and Colton R J 1994 Sensing discrete streptavidin-biotin interactions with atomic force microscopy Langmuir 10 354... 

The biotinylated aptamer (0.5 pM, (see Note 3)) is thermally treated before its immobilization. The thermal treatment can unfold the aptamer strand making the biotin label at the 5 end available for the interaction with streptavidin on the chip surface. Before the immobilization, the biotinylated aptamer is heated at 90°C for 1 min to unfold the DNA strand and then cooled in ice for 10 min to block the DNA in its unfolded structure (44) (see Note 4). 

Fig. 2 a Immobilization procedure based on the streptavidin/biotin interaction. The probe to be immobilized is biotinylated and interacts with streptavidin covalently fixed onto the crystal, b Immobilization procedure based on the direct coupling of a thiolated probe onto the crystal... 

By chemical methods biotin can be attached to other molecules, for example, by bonding to amine groups in proteins, without losing the strong interaction with streptavidin. 

Figure Bl.20.10. Typical force curve for a streptavidin surface interacting with a biotin surface in an aqueous electrolyte of controlled pH. This result demonstrates the power of specific protein interactions. Reproduced with pennission from [81].

S. Miyamoto and P. A. Kollman. Absolute and relative binding free energy calculations of the interaction of biotin and its analogs with streptavidin using molecular dynamics/free energy perturbation approaches. Proteins, 16 226-245, 1993. 

Miyamoto S and P A Kollman 1993a. Absolute and Relative Binding Tree Energy Calculations of the Interaction of Biotin and its Analogues with Streptavidin Using Molecular Dynamics/Free Energy Perturbation Approaches. Proteins Structure, Function and Genetics 16 226-245. 

Figure 6.2 The trifunctional reagent sulfo-SBED reacts with amine-containing bait proteins via its NHS ester side chain. Subsequent interaction with a protein sample and exposure to UV light can cause crosslink formation with a second interacting protein. The biotin portion provides purification or labeling capability using avidin or streptavidin reagents. The disulfide bond on the NHS ester arm provides cleavability using disulfide reductants, which effectively transfers the biotin label to an unknown interacting protein.

After molecules modified with sulfo-NHS-SS-biotin are allowed to interact with avidin or streptavidin probes, the complexes can be cleaved at the disulfide bridge by treatment with 50 mM DTT. Reduction releases the biotinylated molecule from the avidin or streptavidin capture reagent without breaking the (strept)avidin interaction. The use of disulfide biotinylation reagents... 

Figure 18.14 NHS-SS-PEG4-biotin can be used to label a primary antibody molecule that has specificity for a protein or interest. Incubation of the biotinylated antibody with a sample, such as a cell lysate, allows the antibody to bind to its target. Capture of the antibody-antigen complex on an immobilized streptavidin reagent effectively isolates the targeted protein from the other proteins in the sample. The disulfide linkage in the spacer arm of the biotin tag permits elution of the immune complex from the streptavidin support using DTT and without using the strong denaturing condition typically required to break the streptavidin-biotin interaction.

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