The biotin-avidin interaction has been used for decades in laboratory research techniques to label peptides, proteins and other macromolecules to identify and purify these molecules. The key feature of the biotin molecule is its strong affinity for avidin, a protein that has been isolated from the bacteria Streptomyces avidinii and is now available commercially as the streptavidin-biotin conjugate (ABC). This binding specificity allows for biotinylation of peptides or protein to be followed by detection using a variety of methods, including western blotting, fluorescence, immunohistochemistry, and many other assays.
Amine-reactive groups are the most common target for biotinylation, such as NHS esters, sulfo-NHS esters and TFP esters. Other amine-reactive groups, such as cysteine residues exposed at the amino terminus of the protein or glycosylated surfaces, can also be labeled with a biotin molecule. Biotinylation of a protein typically requires a biotin-protein ligase.
Unlike other chemical labels, biotin is soluble in aqueous solutions and can be covalently conjugated to reactive functional groups on proteins without losing its (streptavidin) binding capability. The biotin-(streptavidin)avidin interaction is resistant to pH and temperature changes, organic solutions and denaturing reagents. This makes it ideal for the use in assays that require immobilization of a biotin-labeled molecule to streptavidin coated surfaces such as beads, membranes and microtiter plates.
JPT’s SPOT synthesis technology enables rapid access to biotinylated peptide for high throughput biomedical screening assays that require immobilization onto streptavidin coated beads, membranes and glass slides. JPT also offers a number of cleavable or reversible biotin chemistry options for applications that require a reversible biotin-(streptavidin)avidin interactions and/or elution from the streptavidin-biotin complex.