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From DNA sequence to improved functionality: using protein sequence comparisons to rapidly design a thermostable
M Lehmann1, D Kostrewa, M Wyss
1F.Hoffmann-La Roche Ltd, Grenzacherstrasse 124, CH-4070 Basel, Switzerland. Martin.Lehmann@Roche.com
Protein Engineering
|February 19, 2000
Summary
Researchers de novo constructed consensus phytases, enhancing thermostability for animal feed applications. This protein engineering approach revealed an unexpected link between fungal phytase sequence conservation and increased heat resistance.
Area of Science:
- Biochemistry
- Protein Engineering
- Enzymology
Background:
- Naturally occurring phytases lack the thermostability required for efficient animal feed applications.
- Developing thermostable phytases is crucial for improving nutrient bioavailability in animal diets.
Purpose of the Study:
- To de novo construct consensus phytases with enhanced thermostability.
- To investigate the molecular basis for increased heat resistance in engineered phytases.
Main Methods:
- Comparative analysis of 13 fungal phytase sequences to construct a consensus sequence.
- Determination of the crystal structure of the consensus phytase and comparison with Aspergillus niger phytase.
- Mutational analysis of specific consensus residues to assess their impact on protein stability.
Main Results:
- The consensus phytase exhibited a 15-22°C increase in unfolding temperature compared to parent enzymes.
- Structural comparisons identified consensus residues contributing to enhanced phytase stabilization.
- Mutational analysis confirmed that certain consensus residues unexpectedly increased protein stability.
Conclusions:
- De novo construction of consensus phytases can significantly enhance thermostability.
- An unexpected direct correlation exists between protein sequence conservation and stability in fungal phytases.
- Engineered consensus phytases hold promise for improved animal feed applications.