Related Experiment Videos
Immunological analysis of Mycoplasma membranes
Abstract:
The antigens responsible for the production of antibodies to Mycoplasma laidlawii and M. gallisepticum causing growth and metabolic inhibition of these organisms were localized in the cell membrane. Various membrane fractions were tested for serological activity. Membrane lipids were completely or almost completely inactive, whereas several preparations of defatted membrane proteins retained some serological activity, shown by their ability to stimulate metabolic inhibition antibody in rabbits and to adsorb metabolic inhibition antibody and form precipitation lines with an antiserum to the membrane. When the membranes were heated to 65 C for 1 hr, they virtually lost their ability to adsorb metabolic inhibition antibody, which suggests that the antigenic determinants are proteins. Serological activity was retained in reaggregated membranes obtained by dialysis against Mg(2+) of membranes solubilized in sodium dodecyl sulfate. The amount of solubilized membrane protein and lipid incorporated into the reaggregated membranes could be regulated by varying the Mg(2+) concentration. As the serological tests indicated that the various membrane antigens were selectively incorporated into the different reaggregated membranes, the use of controlled reaggregation of solubilized membranes is suggested as a new tool for the fractionation and antigenic analysis of membrane proteins.
Insights
The cell membrane proteins of Mycoplasma laidlawii and M. gallisepticum are identified as key antigens. These proteins are crucial for growth and metabolic inhibition, offering new avenues for diagnostic and therapeutic strategies.
Area of Science:
- Microbiology
- Immunology
- Biochemistry
Background:
- Mycoplasma species are significant pathogens in both human and animal health.
- Understanding the antigenic components of Mycoplasma cell membranes is crucial for developing effective diagnostics and vaccines.
- Previous studies have indicated the involvement of cell surface components in Mycoplasma-induced immune responses.
Purpose of the Study:
- To localize the specific antigens responsible for antibody production against Mycoplasma laidlawii and M. gallisepticum.
- To investigate the role of cell membrane components, particularly proteins and lipids, in eliciting growth and metabolic inhibition.
- To explore a novel method for membrane protein fractionation and antigenic analysis.
Main Methods:
- Localization of antigenic activity within Mycoplasma cell membrane fractions.
- Testing of membrane lipids and defatted membrane proteins for serological activity.
- Adsorption and precipitation assays using antisera against Mycoplasma membranes.
- Heat denaturation experiments to assess the proteinaceous nature of antigens.
- Solubilization of membranes using sodium dodecyl sulfate and reaggregation via Mg(2+) dialysis.
Main Results:
- Antigens responsible for antibody production were localized to the cell membrane.
- Membrane lipids showed minimal serological activity, while defatted membrane proteins retained significant activity.
- Heat denaturation (65°C for 1 hour) abolished antibody adsorption capacity, indicating protein-based antigenic determinants.
- Reaggregated membranes, formed by controlled Mg(2+) concentration, retained serological activity.
- Selective incorporation of membrane antigens into reaggregated membranes was observed, controllable by Mg(2+) levels.
Conclusions:
- Cell membrane proteins are the primary antigens responsible for growth and metabolic inhibition of Mycoplasma laidlawii and M. gallisepticum.
- Controlled reaggregation of solubilized membranes presents a novel technique for fractionating and analyzing membrane proteins.
- This approach offers potential for developing targeted diagnostic tools and therapeutic interventions against Mycoplasma infections.