Introduction
The basic structure of antibody molecular is composed of four polypeptide chains. That is, it consists of two
identical peptide chains with relatively large molecular weight (heavy chain, H chain) and two identical peptide
chains with relatively small molecular weight (light chain, L chain)composition. There are disulfide bonds within
each heavy chain, each light chain, and between each heavy chain and a light chain. The heavy chain contains about
450-550 amino acid residues, while light chain consisting of approximately 214 amino acid residues that the size is
about half of the heavy chain. As we know, antibody variable region refers to the region located at 1/5 or 1/4
(about 118 amino acid residues) of the H chain near the N-terminus and 1/2 (about 108-111 amino acid residues) of
the L chain near the N-terminus. The amino acid sequence and composition of this region exist large changes, which
determine the antigen-binding specificity of the antibody. Sequencing of the variable region is helpful for the
functional study of the antibody or the correctness of the antibody function.
Fig. 1.
Immunoglobulin and free light chain (FLC) structure. (Hampson J A, et al., 2014)
Our Services
Creative Proteomics provides a mass spectrometry-based antibody light and heavy chain variable
region sequencing service. A variety of protease cleavage are used to generate numerous peptide fragments during the
sequencing process, so that we can obtain the sequence information of each peptide bond in the antibody.
Theoretically, 20-70 different MS/MS spectra are generated for each amino acid (AA) position, and all amino acid
sequences are clearly sequenced, even for the most difficult proline- and arginine-rich peptide sequences can be
parsed. Compared with time-consuming techniques such as Edman sequencing, the mass spectrometry-based protein
sequencing platform we provide can quickly provide you with the amino acid sequence of the variable region with less
time-consuming.
Advantages of Our Services
- For antibody variable regions, each site is covered at least 4 times to achieve full sequence coverage.
- low time cost.
- Low sample volume requirements.
- The sequencing error range is +/- 1.2 Da for the light chain and +/- 1.8 Da for the heavy chain with high
accuracy.
- For customized services, we can choose to measure only the light chain, heavy chain or variable region of the
antibody according to customer needs.
Creative Proteomics not only provides global customers with comprehensive antibody light and heavy
chain variable region sequencing services to accelerate antibody discovery, and also our scientists can provide
customized services according to your specific requirements, which are described in a detailed project report. If
you are interested in our services, please keep free to contact us.
References
- Foreman H C, Frank A, Stedman T T. (2021) Determination of variable region sequences from hybridoma
immunoglobulins that target Mycobacterium tuberculosis virulence factors. PLoS One. 16(8):e0256079.
