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Endosialidases: Versatile Tools for the Study of Polysialic Acid
Elina Jakobsson1, David Schwarzer, Anne Jokilammi
1Department of Medical Biochemistry and Genetics, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland.
Topics in Current Chemistry
|August 2, 2012
Summary
Endosialidases, enzymes that degrade polysialic acid, have a unique structure with multiple binding sites. Their mechanism and applications in medicine and biochemistry are detailed, offering new tools for research.
Area of Science:
- Biochemistry
- Structural Biology
- Microbiology
Background:
- Polysialic acid (PSA) is a bacterial and eukaryotic cell surface polymer.
- Endosialidases are bacteriophage enzymes that specifically cleave PSA.
Purpose of the Study:
- To review structural and biochemical data on endosialidases.
- To discuss their catalytic mechanism and applications.
Main Methods:
- X-ray crystallography to determine endosialidase structure.
- Biochemical assays to study enzyme activity and mechanism.
- Protein engineering to create detection tools.
Main Results:
- Endosialidase structure is trimeric with an active site and two additional PSA binding sites.
- Protein folding relies on an intramolecular chaperone domain.
- A processive catalytic mechanism is proposed.
- Engineered endosialidase-green fluorescent protein fusions detect PSA.
Conclusions:
- Endosialidases are versatile tools for studying PSA's biological roles.
- Structural and mechanistic insights advance biochemical and medical applications.
- Engineered endosialidases offer specific PSA detection methods.
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