1. Cross-linking of peptide and carrier protein

The molecular weights of most peptides are too small to produce an immune response in animals. Cross-linking peptides with carrier proteins such as KLH not only increases the size of the antigen, but also enhances immunity. We can provide cross-linking with both KLH and BSA proteins. Most customers choose to cross-link with KLH because KLH has better immunity, and BSA is used as a Blocking agent in many experiments, because animals produce antibodies to both peptides and carrier proteins, which can cause false positives.

2. Use of antibodies

Because antibodies have a strong binding ability with many biological molecules, especially proteins and peptides, antibodies occupy a unique and important position in biomedical research, and antibodies are needed in the characteristics, content determination, distribution analysis and protein confirmation. For example: diagnostic kits such as early pregnancy kits; protein microalloy, immunohistochemistry and common ELISA tests. Due to the strong ability of antibodies to bind to specific molecules, many efforts have been made to use antibodies for in vivo therapy. Examples of success include Genentech's Herceptin, for a specific type of breast cancer, and IDEC Pharmaceuticals' Ritaxan, for a specific type of Non-Hodgkin's Lymphomas B-cells.

3. Antigen and recognition area

In most cases, antigen and immunogen are used interchangeably and the differences between them are minor. They refer to two types of interactions between a molecule and the immune system, respectively. An immunogen is a molecule that causes the immune system of a biological tissue to produce an immune response, and an antigen is a molecule that binds to the products of this immune reaction, so immunogen must be antigen, but antigen is not necessarily immunogen. antigen is a general antigen, specifically a molecule that can bind to antibodies, the product of the immune response.

epitopes refers to a specific sequence of an antigen molecule that is directly bound to an antibody. For any antigen (antigen protein), there are likely to be multiple antibody recognition regions. For the production of antibodies, the recognition region of the part easily recognized by antibodies is the most ideal.

4. Chemical method for KLH crosslinking

We activated KLH with MBS, which can link the free -SH above the carrier protein (KLH) to the side chain -SH of Cys at the end of the peptide. This method is direct, highly specific, and stable, and usually selects the end that is not important for immunity for cross-linking.

It is also a feasible method to activate -COOH on EDC carrier and link -COOH of carrier with -NH2 of peptide. However, we only recommend this method when there are multiple Cys in the peptide sequence. If there are multiple -COOH or -NH2 genes in the peptide chain, this method is not recommended, because it will cause multiple cross-linking conditions, which will affect the structure of the peptide. In addition to KLH, commonly used carrier proteins include BSA, Ovalbumin, etc. The advantage of KLH is that it does not interfere with ELISA or Western Blot experiments.

5. the peptide chain length of the antigen peptide crossbinding

10-15 residues are usually recommended for cross-linking. The longer the peptide chain, the more areas the antibody recognizes, but the more opportunities there are to form a stable secondary structure. It's no longer the natural form. Peptides that are too short are usually not useful unless there is a good reason, such as sequence homology with related family proteins or other proteins.

6. The reason why KLH cross-linked peptide solution is milky

KLH is a large, polymerized protein. Because of its structure and size, its solubility in water is very limited, so it is milky, which does not affect its immunity, and this cloudy solution can directly immunize animals.

7. Antibody production

The production of antibodies depends on many factors: the selection of the recognition area, the synthesis of peptides, the cross-linking of vectors, the procedure of immunity and the physiological system of the animal, etc., so the production of antibodies is not the same. 5 to 25mg is the normal range.

For more information about custom peptide synthesis, antigenic peptide synthesis, please visit www.omizzur.com