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Mutations in the procaspase-3 dimer interface affect the activity of the zymogen
Cristina Pop1, Brett Feeney, Ashutosh Tripathy
1Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, USA.
Biochemistry
|October 22, 2003
Summary
Altering the procaspase-3 dimer interface impacts enzyme activity. Mutations at valine 266 can pseudoactivate or abolish caspase activity, highlighting the interface
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- The procaspase-3 dimer interface is crucial for zymogen maturation.
- Understanding this interface is key to controlling caspase activity.
Purpose of the Study:
- To investigate the role of residue 266 at the procaspase-3 dimer interface.
- To determine how mutations at this site affect enzyme activity and conformation.
Main Methods:
- Site-directed mutagenesis of procaspase-3 at residue 266 (V266E and V266H).
- Enzyme activity assays.
- Analysis of dimeric properties and active site conformation.
Main Results:
- V266E mutation resulted in a ~60-fold increase in enzyme activity (pseudoactivation).
- V266H mutation abolished both procaspase-3 and mature caspase activity.
- Mutations did not affect dimeric properties but altered active site loop positioning and stability.
Conclusions:
- The integrity of the procaspase-3 dimer interface is essential for proper active site conformation.
- Specific mutations at the dimer interface can drastically modulate caspase activity.
- These findings provide insights into caspase regulation mechanisms.