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Exploring Caspase Mutations and Post-Translational Modification by Molecular Modeling Approaches
Published on: October 13, 2022
Substrate-induced conformational changes occur in all cleaved forms of caspase-6
Sravanti Vaidya1, Elih M Velázquez-Delgado, Genevieve Abbruzzese
1Department of Chemistry, University of Massachusetts Amherst, 104 Lederle Graduate Research Tower,710 North Pleasant Street, Amherst, MA 01003, USA.
Journal of Molecular Biology
|November 30, 2010
Summary
Caspase-6, a protease linked to neurodegenerative diseases, has a unique structure. This study reveals its extended conformation is stable but changes upon substrate binding, offering therapeutic insights.
Area of Science:
- Biochemistry
- Structural Biology
- Neuroscience
Background:
- Caspase-6 is an apoptotic protease implicated in Huntington's and Alzheimer's disease progression.
- Understanding caspase-6's molecular basis is crucial for developing treatments for neurodegenerative diseases.
- The unique extended conformation of caspase-6 differs from other caspases, raising questions about its catalytic competence.
Purpose of the Study:
- To investigate the structural and functional roles of the prodomain and intersubunit linker in caspase-6.
- To determine if the extended conformation of caspase-6 is catalytically active or requires rearrangement for substrate binding.
- To elucidate the conformational changes of caspase-6 upon substrate binding.
Main Methods:
- Generation of caspase-6 cleavage variants, including a constitutively two-chain form.
- Determination of crystal structures of caspase-6 with and without the intersubunit linker.
- Analysis of caspase-6 stability and conformational changes in different states.
Main Results:
- Caspase-6 exhibits inherent stability compared to related caspases.
- The prodomain and intersubunit linker enhance caspase-6 stability while maintaining an extended conformation in the unliganded state.
- Caspase-6 undergoes a significant conformational change upon substrate binding, resembling canonical caspases.
Conclusions:
- The prodomain and intersubunit linker stabilize caspase-6 but do not preclude substrate-induced conformational changes.
- Caspase-6 likely adopts a canonical caspase structure upon substrate binding, suggesting a mechanism for its function in neurodegeneration.
- These findings provide structural insights into caspase-6 regulation and potential therapeutic targeting for neurodegenerative diseases.
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