Related Experiment Video
Updated: Jul 16, 2026
Identification of Antibacterial Immunity Proteins in Escherichia coli using MALDI-TOF-TOF-MS/MS and Top-Down Proteomic Analysis
Published on: May 23, 2021
First identification and functional characterization of an immunogenic protein in unculturable haemotrophic
Ludwig E Hoelzle1, Katharina Hoelzle, Alois Harder
1Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland. lhoelzle@vetbakt.unizh.ch
Abstract:
The antigenic structures of the haemotrophic Mycoplasma suis, an epicellular parasite of porcine erythrocytes, are largely unknown due to its unculturability. In this study, serological proteome and mass spectrometry analyses allowed the characterization of M. suis proteins targeted by the porcine antibody response: two proteins with characteristics of heat shock proteins, two proteins with characteristics of glycolytic enzymes, a RNA helicase- and an actin-like protein. The DnaK-like protein of M. suis (HspA1) was further analysed genetically and functionally. Its encoding gene (M. suis a1 gene) is 1.830 bp in size and corresponds to a 67 kDa protein. Immunoelectron microscopy verified the surface accessibility of HspA1 in M. suis. Recombinant HspA1 expressed in Escherichia coli demonstrated ATPase activity and antigenicity in experimentally infected pigs. In conclusion, this first identification and recombinant expression of an antigenic protein of M. suis provides the basis for the development of vaccines and new in vitro diagnostic assays.
Insights
Researchers identified key antigenic proteins of Mycoplasma suis, a swine blood parasite, including a heat shock protein (HspA1). This finding paves the way for developing Mycoplasma suis vaccines and diagnostic tools.
Area of Science:
- Veterinary Immunology
- Microbiology
- Parasitology
Background:
- Antigenic structures of Mycoplasma suis, an epicellular parasite of porcine erythrocytes, are largely unknown due to its unculturability.
- Understanding these antigens is crucial for developing effective diagnostics and vaccines against swine mycoplasmosis.
Purpose of the Study:
- To characterize Mycoplasma suis proteins targeted by the porcine antibody response.
- To genetically and functionally analyze the DnaK-like protein (HspA1) of M. suis.
- To provide a basis for developing vaccines and in vitro diagnostic assays for M. suis.
Main Methods:
- Serological proteome analysis to identify M. suis proteins recognized by antibodies.
- Mass spectrometry to characterize the identified proteins.
- Genetic analysis and functional studies of the HspA1 protein, including recombinant expression in E. coli.
- Immunoelectron microscopy to verify surface accessibility of HspA1.
Main Results:
- Characterized several M. suis proteins, including heat shock proteins, glycolytic enzymes, RNA helicase, and actin-like proteins.
- Identified and analyzed the DnaK-like protein (HspA1), a 67 kDa protein encoded by the 1.830 bp M. suis a1 gene.
- Verified the surface accessibility of HspA1 using immunoelectron microscopy.
- Demonstrated ATPase activity and antigenicity of recombinant HspA1 in experimentally infected pigs.
Conclusions:
- This study presents the first identification and recombinant expression of an antigenic protein of Mycoplasma suis.
- The characterized HspA1 protein serves as a potential target for vaccine development.
- The findings lay the groundwork for novel in vitro diagnostic assays for Mycoplasma suis infections.
