Enzyme Labeling of Proteins

BOC Sciences, a leading CRO focused on bioconjugation, offers services for enzyme labeling of proteins and the preparation of antibody conjugates for various immunoassays and related applications.

What is Enzyme Labeling of Proteins

Enzyme labeling of proteins refers to the process of covalently attaching an enzyme to a protein molecule. This labeling allows for the detection, quantification, or purification of the protein using enzymatic activity as a readout. Various enzymes can be employed for protein labeling, including horseradish peroxidase (HRP), alkaline phosphatase (AP), and β-galactosidase. These enzymes possess desirable properties such as stability, high catalytic activity, and compatibility with a wide range of substrates.

Enzymes are conjugated to labeling molecules using several methods, including chemical cross-linking, biotinylation, and genetic fusion. Chemical cross-linking involves the covalent attachment of enzymes to labeling molecules, while biotinylation utilizes the strong and specific interaction between biotin and streptavidin. Genetic fusion involves the fusion of the gene encoding the enzyme with the gene encoding the target protein, leading to the expression of a fusion protein with both enzyme and protein domains.

Our Services for Enzyme Labeling of Proteins

Our experienced and dedicated team of scientists are able to bind enzyme molecules to proteins of interest according to the needs of our customers.

• Selection of Enzymes

Choose an enzyme that is compatible with the desired detection method and assay conditions. For example, AP can hydrolyze phosphatase substrates (e.g. p-nitrophenyl phosphate) to produce a colored or fluorescent product, which is commonly used in ELISA and immunohistochemistry.

• Chemical Cross-Linking

The labeling reagent should contain a reactive group or a chemical cross-linker that can bind to specific sites on the protein. Combine the purified protein with the activated enzyme and the labeling reagent. The reaction is typically carried out under mild conditions, such as specific temperature, pH, or buffer conditions.

• Purification

Several purification strategies can be employed to obtain purified enzyme-labeled proteins, including affinity chromatography, size-exclusion chromatography, ion-exchange chromatography, precipitation, or magnetic bead separation.

Application of Enzyme Labeling of Proteins

• Western Blotting

The method of Western blotting is frequently used to identify certain proteins in complicated protein mixtures. By producing a detectable signal upon reaction with suitable substrates, enzyme labeling makes it easier to see target proteins. In a Western blot analysis, the enzymes allow for the exact identification and quantification of proteins of interest by coupling to antibodies that recognize the target protein.

• Immunohistochemistry

The enzyme label amplifies the signal, allowing for the localization and distribution of proteins within cells and tissues to be observed under a microscope.

• Enzyme-Linked Immunosorbent Assay (ELISA)

ELISA can be used detect and quantify various analytes, including proteins, hormones, and antibodies. By coupling enzymes to antibodies or antigens, ELISA can accurately measure protein concentrations in biological samples, making it invaluable in diagnostics, drug development, and research.

• Biosensors

Enzyme labeled proteins can be incorporated into biosensor platforms for the detection of specific analytes. The biosensors can be used in environmental monitoring, medical diagnostics, and food safety.

Why Choose Us for Enzyme Labeling of Proteins

• Nearly 1:1 ratio of enzyme to interested target
• Optimized sample preparation and conjugation
• High product yield and purity
• Strict validation and characterization
• Scale-up production up to kilograms
• Data analysis, detailed report with results and discussion
• Analytical HPLC and MS analyses are performed in every development cycle.