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Updated: May 21, 2026
Natural Product Discovery with LC-MS/MS Diagnostic Fragmentation Filtering: Application for Microcystin Analysis
Published on: May 31, 2019
Comparative proteomics between natural Microcystis isolates with a focus on microcystin synthesis
Angela Tonietto1, Bernardo A Petriz, Wérika C Araújo
1Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Pós Graduação em Ciências Genômicas e Biotecnologia, SGAN 916 Norte Av, W5, Brasília, DF, Brazil. ocfranco@gmail.com.
Background:
Microcystis aeruginosa is a species of cyanobacteria commonly found in a number of countries and frequently related to animal poisoning episodes due to its capacity to produce the cyanotoxin known as microcystin. Despite vast literature on microcystin structures and their deleterious effects, little is known about its synthesis by cyanobacteria. Therefore, this study used proteomic tools to compare two M. aeruginosa strains, contrasting them for microcystin production.
Results:
2-DE gels were performed and 30 differential protein spots were chosen. Among them, 11 protein spots were unique in the toxin producing strain and 8 in the non-toxin producing strain, and 14 protein spots were shown on both 2-DE gels but expressed differently in intensity. Around 57% of the tandem mass spectrometry identified proteins were related to energy metabolism, with these proteins being up-regulated in the toxin producing strain.
Conclusions:
These data suggest that the presence of higher quantities of metabolic enzymes could be related to microcystin metabolism in comparison to the non-toxin producing strain. Moreover, it was suggested that the production of microcystin could also be related to other proteins than those directly involved in its production, such as the enzymes involved in the Calvin cycle and glycolysis.
Insights
Proteomics revealed that Microcystis aeruginosa strains producing microcystins have higher levels of metabolic enzymes. This suggests a link between energy metabolism and cyanotoxin synthesis in these common aquatic bacteria.
Area of Science:
- Environmental microbiology
- Proteomics
- Cyanobacteria research
Background:
- Microcystis aeruginosa is a globally prevalent cyanobacterium.
- It produces microcystin, a potent cyanotoxin linked to animal poisonings.
- Understanding microcystin synthesis in cyanobacteria remains limited.
Purpose of the Study:
- To compare microcystin production in two M. aeruginosa strains using proteomic tools.
- To investigate the protein expression differences between toxin-producing and non-toxin-producing strains.
- To identify proteins potentially involved in microcystin synthesis.
Main Methods:
- Two-dimensional gel electrophoresis (2-DE) was employed to separate proteins.
- Differential protein spots between strains were identified.
- Tandem mass spectrometry was used for protein identification.
Main Results:
- 30 differential protein spots were identified between the two M. aeruginosa strains.
- 57% of identified proteins were related to energy metabolism and upregulated in the toxin-producing strain.
- Specific proteins unique to each strain and differentially expressed proteins were noted.
Conclusions:
- Higher quantities of metabolic enzymes in toxin-producing strains may correlate with microcystin metabolism.
- Microcystin production might involve proteins beyond those directly in its synthesis pathway, including those in the Calvin cycle and glycolysis.
