As we know, the innate affinity between streptavidin and biotin is one of the strongest non-covelant interactions, with femtomolar affinity, and can resist changes in pH and temperature.
My question, is whether anyone has experience of the strength of this interaction being reduced, when the biotin is coupled to a second molecule, such as a peptide. Does this make the streptavidin-biotin interaction less stable?
Thanks for any input!
Brittany
1. Savage MD. An Introduction to Avidin-Biotin Technology and Options for Biotinylation. In: Meier T, Fahrenholz F, editors. A Laboratory Guide to Biotin-Labeling in Biomolecule Analysis, BioMethods: Birkhäuser Basel; 1996. p 1-29.
In this book it is suggested that the avidin-biotin link can be disrupted with 8 M guanidine HCl pH=1.5.
I have no experience regarding the decrease of the interaction between avidin and conjugated biotin as compared with free biotin. in principle the carboxylic acid moiety of biotin (valeric acid sidechain) which is used for coupling also interacts with Asn49 ans Ser88 aminoacids of avidin. However as the C=O group is preserved but just the free OH is changed to -O- or -NH- I guess the interaction is not significantly affected.
Hello Brittany Wingham ,
Direct answer of your question - short incubation in nonionic aqueous solutions at temperatures above 70 degrees C can efficiently break the interaction without denaturing the streptavidin tetramer. Both biotin and the streptavidin remain active after dissociation and both molecules can therefore be re-used. The efficiency of the regeneration allowed solid supports with streptavidin to be used many times, here exemplified with the multiple re-use of streptavidin beads used for sample preparation prior to automated DNA sequencing. The results suggest that streptavidin regeneration can be introduced as an improvement in existing methods and assays based on the streptavidin system as well as emerging solid phase applications in fields, such as microfluidics and nanotechnology.
Best regards,
Babu
- Badges
- Science topic
- Similar topics
- Biological Science
- Biochemistry
- Enzymology
- Enzymes