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Updated: Aug 9, 2026
10:34
Preparation of Quality Inositol Pyrophosphates
Published on: September 3, 2011
Summary
The glycolytic enzyme triose phosphate isomerase refolds and reactivates rapidly after denaturation. Dimerization is crucial for activity, indicating monomers are largely inactive.
Area of Science:
- Biochemistry
- Enzymology
Background:
- Triose phosphate isomerase (EC 5.3.1.1) is a key glycolytic enzyme.
- Enzyme structure and refolding kinetics are critical for understanding function.
Purpose of the Study:
- To investigate the refolding and reactivation process of triose phosphate isomerase.
- To determine the role of dimerization in enzyme activity recovery.
Main Methods:
- Enzyme denaturation and unfolding using guanidinium chloride.
- Spectroscopic monitoring of unfolding (E233) and refolding.
- Assay of enzymic activity during refolding.
- Proteolysis studies using subtilisin.
Main Results:
- Unfolding in 3M guanidinium chloride was rapid (t1/2 ~1 min).
- Refolding occurred in two first-order processes upon dilution.
- Enzymic activity regain was concentration-dependent at low protein levels, suggesting dimerization is rate-limiting.
- The rate of activity regain matched the slower refolding process.
- Proteolysis competed with refolding at lower enzyme concentrations.
Conclusions:
- Triose phosphate isomerase monomers exhibit minimal to no activity.
- Dimerization is essential for the regain of full enzymic activity.
- Refolding kinetics are closely linked to functional recovery.
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