What is biotinylation?

Biotinylation refers to the process of covalently attaching biotin to proteins, nucleic acids or other molecules. Due to the small molecular weight of biotin (the molecular weight is 244.31), the biotinylation reaction is fast, efficient and not easily disturbed. Biotinylated molecules can interact with streptavidin and avidin through biotin, and are not affected by high heat, pH, and proteolysis. The binding of biotin to streptavidin and avidin is specific and efficient, so this interaction has a wide range of applications in many fields of biotechnology.

In addition, multiple biotinylated molecules can be cross-linked to form a protein of interest to researchers, while allowing binding to multiple streptavidin, avidin, and neutravidin proteins, increasing this protein detection sensitivity. In addition, there are numerous applications of biotinylated molecules yet to be developed.

Proteins can be biotinylated chemically or enzymatically. Chemical biotinylation utilizes a variety of coupling chemicals to produce non-specific biotinylation of amines, carboxylates, sulfhydryls, and carbohydrates (eg, NHS coupling biotinylates any primary amine in a protein). Enzymatic biotinylation results in the biotinylation of specific lysines within specific sequences by bacterial biotin ligases.

Most chemical biotinylation reagents consist of a reactive group attached to the valeric acid side chain of biotin through a linker. Since the biotin-binding pocket in avidin/streptavidin is buried beneath the protein surface, biotinylation reagents with longer linkers are needed because they make the biotin molecule more difficult to use once attached to its target. Easily accessible binding avidin/streptavidin/neutrophil. This linker can also mediate the solubility of biotinylating reagents, linkers incorporating polyethylene glycol (PEG) can solubilize water-insoluble reagents or to some extent increase the solubility of biotinylating reagents that are already soluble.

Biotinylation reagents can be used to target specific functional groups or residues, including primary amines, sulfhydryls, carboxyl groups, and carbohydrates. The variety of biotinylation reagents with different functional group specificities is very useful, allowing one to choose reagents that do not inactivate the target macromolecule. In addition to functional group specificity, biotinylation reagents have different solubility properties that can focus biotinylation in different intracellular or extracellular microenvironments. Cleavable or reversible biotinylation reagents enable specific elution of biotinylated molecules from biotin-binding proteins. The variability of these reagents greatly expands the range of applications of avidin-biotin chemistry.

Biotin labeling refers to the biotin avidin system, which is a new type of biological reaction amplification system developed in the late 1970s. With the advent of various biotin derivatives, BAS was soon widely used in various fields of medicine. In recent years, a large number of studies have confirmed that the biotin avidin system can be combined with almost all kinds of markers that have been successfully studied. The strong binding of biotin and avidin with high affinity and multi-stage amplification effect make BAS immunolabeling and related tracer analysis more sensitive. It has become a new technology widely used in the qualitative and quantitative detection of trace antigens and antibodies, as well as in localization observation research.

Biotin-labeled (i.e. biotinylated) proteins are often detected or purified using avidin conjugates in many protein research applications, including enzyme-linked immunosorbent assay (ELISA), Western blot analysis, immunohistochemistry (IHC) ), immunoprecipitation (IP) and other affinity purification methods, cell surface labeling, and flow cytometry/fluorescence-activated cell sorting (FACS).

Biotinylated labeling method
– Enzymatic biotinylation
– Primary amine biotinylation
– Sulfhydryl biotinylation
– Carboxy biotinylation
– Glycoprotein biotinylation
– Oligonucleotide biotinylation
– Non-specific biotinylation

Biotin PEG linkers (reagents) are useful biotinylation reagents for non-radioactive purification, detection, immobilization, labeling and targeting. The interaction affinity between biotin (vitamin H) and avidin is the strongest. It allows rapid discrete binding of biotin-containing molecules to avidin conjugates. The complexes formed become stable under extreme pH, temperature, organic solvents and other denaturants.

AxisPharm offers biotinylation reagents with various functional groups. Many factors must be carefully considered when determining the correct biotinylation reagent to use, including solubility, spacer length, reversibility, and functional groups.

Our biotin PEG linkers improve reagent and conjugation solubility and minimize toxic and immunological effects. Monodisperse PEG linkers also provide our customers with precise control over spacer length for optimizing conjugation functionality in specific biotin-binding assays involving streptavidin, avidin, and other avidin proteins.