Dibenzocyclooctyne (DBCO)*-containing (desthio) biotinylation reagents can be used for the labeling of Azide-tagged biomolecules via Cu(I)-free strain-promoted Alkyne-Azide Click Chemistry (SPAAC).
Labeling of a molecule (e.g. a protein or nucleic acid) with biotin/desthiobiotin is routinely performed for its subsequent affinity purification via streptavidin agarose or detection with fluorescent or HRP-labeled streptavidin. Due to the extremely high affinity of biotin towards streptavidin (KD = 10-15 M), the biotinylated molecule/streptavidin-interaction is essentially irreversible under physiological conditions. Desthiobiotin however, binds less tightly to streptavidin (KD = 10-11 M) and desthiobiotinylated molecules are therefore easily eluted from the complex in the presence of excess Biotin.
*DBCO is also known as ADIBO (= Azadibenzocyclooctyne) or DIBAC (= Dibenzoazacyclooctyne)