The biotin–avidin interaction is commonly exploited to detect and/or purify proteins because of the high specificity
that these two molecules have for each other. Biotinylation is the process of attaching biotin to proteins and other
When selecting the biotinylating reagents, the user need consider the following aspects.
The biotin-binding domain in avidin/ streptavidin molecules are buried 9Å below the surface and hence, the presence of bulky groups in the vicinity of the biotin-binding site may create steric hindrances and reduce the binding efficiency and the sensitivity of detection methods. Greater binding capacity can be realized by using biotin derivatives that have large spacer arms. Extended spacer arms afford the ability to overcome steric hindrances and bind deep within the binding sites of the avidin/ streptavidin molecules.
Solubility of biotin reagents varies greatly, with some being only soluble in organic solvents, i.e. DMSO and DMF, while others has sulfo-NHS or different length of PEG to enhance the solubility.
This has become of great interest in studies of cell surface proteins and therefore membrane trafficking and cell signaling. The biotin reagents that are not membrane permeable are excellent candidates for labeling membrane surface proteins.
Biotin tags are often used for protein purification, however with the biotin:(strept)avidin binding affinity being one of the strongest known it is often difficult to release the protein from the avidin. In fact, 8M guanidine at pH1.5 is often used, which has severe detrimental effects on the protein of interest. Several biotin reagents have disulfide bonds that can be reduced to release the protein of interest under mild conditions and other biotin reagents can be removed from the protein with changes in pH.
The reagents offered have numerous reactive groups that can couple to amines, sulfhydryls, carboxyls and carbohydrates. Conjugation of biotin reagents to proteins and other molecules generally does not have adverse effects on the biological properties of the target molecules, unless biotin reagents are conjugating to or modifying active residues or sites of the protein. Due to this, it is important to find an appropriate biotin reagent and optimal biotin conjugation efficiency for maintaining the functional properties of the target molecules.
The conjugation efficiency of the reactions is dependent on the reaction groups and the buffers used for the reactions as many coupling reactions are sensitive to pH and chemical composition.
BroadPharm has all kinds of biotinlyation reagents for meet the need of your advanced research. The variability of these reagents substantially expands the range of applications for avidin–biotin chemistry