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Updated: Apr 25, 2026
Peptide Scanning-assisted Identification of a Monoclonal Antibody-recognized Linear B-cell Epitope
Published on: March 24, 2017
Identification of B cell epitopes in the MSG1 protein of Mycoplasma suis
Chen Chang1, Yao Zou, Yufeng Li
1Key Laboratory of Bacteriology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing, China .
Abstract:
Mycoplasma suis (M. suis) is an extracellular bacterial organism that attaches to and causes deformity and damage to porcine red blood cells. M. suis glyceraldehyde-3-phosphate dehydrogenase-like protein 1 (MSG1), a membrane-associated adhesion protein, plays a major role in M. suis attachment and infection of porcine erythrocytes. In order to identify the epitopes in MSG1 protein of M. suis, recombinant MSG1 (rMSG1) expressed in Escherichia coli Top10 was purified with affinity chromatography and used to immunize BALB/c mice to prepare and screen monoclonal antibodies (MAbs). Western blot results showed that 1C10, 2F10, 4G10, and 10E9 can specifically react with recombinant MSG1 and M. suis. Moreover, 23 truncated fragments of MSG1 were amplified and cloned into pET-32a vector and induced by IPTG. Different recombinant truncated proteins were used to identify B cell epitopes in the rMSG1 protein. Epitope mapping revealed that MAb 1C10 recognizes the linear epitope D(291)THGSVF(297); MAb 2F10 recognizes the linear epitope L(251)CLKI(255); and MAbs 4G10 and 10E9 recognize the linear epitope I(268)KDGENE(274). The alignment of MSG1 epitope sequences with that of different M. suis strains accessed on NCBI showed that one epitope is highly conserved in M. suis strains. This research is the first to examine the epitopes in MSG1 of M. suis and demonstrate the variations of epitopes.
Insights
Researchers identified specific B cell epitopes on Mycoplasma suis glyceraldehyde-3-phosphate dehydrogenase-like protein 1 (MSG1). This study maps key regions of MSG1, aiding in understanding M. suis infection and developing diagnostic tools.
Area of Science:
- Veterinary Microbiology
- Immunology
- Protein Chemistry
Background:
- Mycoplasma suis (M. suis) is an extracellular bacterium that infects porcine red blood cells, causing significant damage.
- The M. suis glyceraldehyde-3-phosphate dehydrogenase-like protein 1 (MSG1) is crucial for bacterial attachment to erythrocytes.
- Understanding MSG1 epitopes is vital for developing diagnostic and control strategies against M. suis infections.
Purpose of the Study:
- To identify and characterize the B cell epitopes within the MSG1 protein of Mycoplasma suis.
- To generate and screen monoclonal antibodies (MAbs) against MSG1 for epitope mapping.
- To assess the conservation of identified epitopes across different M. suis strains.
Main Methods:
- Recombinant MSG1 (rMSG1) was expressed in E. coli and purified.
- BALB/c mice were immunized with rMSG1 to produce monoclonal antibodies (MAbs).
- Western blot analysis was used to confirm antibody specificity. Epitope mapping was performed using truncated MSG1 fragments.
Main Results:
- Four MAbs (1C10, 2F10, 4G10, 10E9) specifically recognized rMSG1 and M. suis.
- Epitope mapping identified linear epitopes: D(291)THGSVF(297) for MAb 1C10, L(251)CLKI(255) for MAb 2F10, and I(268)KDGENE(274) for MAbs 4G10 and 10E9.
- Sequence alignment revealed that one identified epitope is highly conserved among M. suis strains.
Conclusions:
- This study provides the first detailed examination of MSG1 epitopes in M. suis.
- The identified linear epitopes are potential targets for diagnostic assays and vaccine development.
- Variations and conservation patterns of MSG1 epitopes offer insights into M. suis evolution and host-pathogen interactions.
