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Updated: Jul 30, 2026
Peptide Scanning-assisted Identification of a Monoclonal Antibody-recognized Linear B-cell Epitope
Published on: March 24, 2017
[Studies of epitope specificity of polyclonal antibodies against Proteus mirabilis R mutants]
B Bartodziejska1, J Radziejewska-Lebrecht, M Lipińska
1Instytut Mikrobiologii i Immunologii Uniwersytetu Lódzkiego.
Abstract:
The chemical structure of the following P. mirabilis R mutants lipopolysaccharide (LPS) were already established: R110/1959 (Ra), R4/028 (Rc) and R45/1959 (Re). In this report we focus on P. mirabilis R5/O28, R13/1959 and R14/1959 and R14/1959. The last one corresponds to Salmonella transient forms, and synthesis truncated core oligosaccharide lacking terminal DD-Hep and nevertheless substituted by T polysaccharide whose structure occurred to be similar to P. penneri 42 O-repeating unit. The knowledge of chemical structure of P. mirabilis R mutants lipopolysaccharides led us to the study of the epitope specificity of rabbit polyclonal R specific antisera. The results show strong structural and serological relatedness of LPS from P. mirabilis R110 and R13. Antibodies against P. mirabilis R4 recognize in homologous LPS an epitope sharing oligosaccharide Glc-Hep. The serological studies revealed also close similarities of LPS from P. mirabilis R14 and P. mirabilis S1959, O28 as well as P. penneri 42. These data indicate that polyclonal antibodies against P. mirabilis R14 are directed against four epitopes: two in T-polysaccharide (D-Glc-(beta 1,4)-D-Glc and terminal GalA residue) and two in core oligosaccharide (D-Glc-(alfa 1,6)-D-Glc and terminal GlcNAc residue) of lipopolysaccharide molecule.
Insights
This study characterizes lipopolysaccharide (LPS) structures in P. mirabilis R mutants, revealing structural and serological similarities between specific mutants and related bacteria. These findings enhance understanding of LPS epitopes and bacterial relatedness.
Area of Science:
- Microbiology
- Immunochemistry
- Bacterial Genetics
Background:
- Lipopolysaccharide (LPS) structure is crucial for bacterial identification and immune response.
- Previous studies established the LPS structures of several P. mirabilis R mutants (Ra, Rc, Re).
- This research investigates the LPS structures of P. mirabilis R5, R13, and R14 mutants.
Purpose of the Study:
- To elucidate the chemical structures of P. mirabilis R5, R13, and R14 lipopolysaccharides (LPS).
- To investigate the epitope specificity of rabbit polyclonal R-specific antisera against these LPS structures.
- To determine the structural and serological relatedness between P. mirabilis R mutants and other bacterial species.
Main Methods:
- Chemical analysis to determine the precise structure of P. mirabilis R mutant LPS.
- Serological assays using rabbit polyclonal antisera to identify epitope specificities.
- Comparative analysis of LPS structures and serological cross-reactivity.
Main Results:
- The LPS of P. mirabilis R14 was found to have a truncated core oligosaccharide, lacking DD-Hep and substituted with a T polysaccharide similar to P. penneri 42.
- Strong structural and serological relatedness was observed between P. mirabilis R110 and R13 LPS.
- Antibodies against P. mirabilis R4 recognized a Glc-Hep oligosaccharide epitope in homologous LPS.
- P. mirabilis R14 LPS showed close similarities to P. mirabilis S1959, O28, and P. penneri 42 LPS.
- Antibodies against P. mirabilis R14 targeted four distinct epitopes within the LPS molecule: two in the T-polysaccharide and two in the core oligosaccharide.
Conclusions:
- The study successfully characterized the LPS structures of P. mirabilis R5, R13, and R14 mutants.
- Significant structural and serological relationships were identified between P. mirabilis R mutants and other bacterial species, including P. penneri.
- The findings provide detailed insights into LPS epitope specificity and contribute to understanding bacterial classification and host-pathogen interactions.
