Thermostable Phytase Variants via Disulfide Bridge Engineering
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Solution Overview
Problem
Current phytases, particularly those from Escherichia coli, have limitations in thermostability and stability across various conditions, which affects their performance in animal feed applications, such as phytate degradation and nutrient release.
Innovation Solution
Development of phytase variants with altered disulfide bridges, specifically introducing new pairs like 52C/99C, to enhance thermostability and stability, along with modifications in specific positions for improved thermal properties and substrate specificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If new disulfide bridges are introduced to enhance thermostability, then the enzyme structure becomes more complex
Solution Approach 1:
The patent applies parameter changes by systematically varying the position and number of disulfide bridges in the phytase enzyme structure. Specific cysteine residues are introduced at defined positions (e.g., C52, C99) to form new disulfide bonds, transforming the enzyme's structural parameters to achieve enhanced thermostability while maintaining catalytic function.
2Reliability
If multiple cysteine residues are introduced to form disulfide bridges, then the protein sequence becomes more complex
Solution Approach 1:
The patent applies local quality by introducing cysteine residues at specific local positions within the enzyme structure rather than uniformly throughout. The disulfide bridges are strategically placed at particular domains or regions where they can provide maximum structural stabilization with minimal impact on overall sequence complexity and catalytic activity.
Data Source
Figure 1
AI summary
The present invention relates to a phytase which has at least 70% identity to a phytase derived from E. coli and comprises at least one modification as compared to this phytase. These phytase variants have modified, preferably improved,properties, such as thermostability, temperature profile, pH profile, specific activity, performance in animal feed, reduced protease sensitiliby, and/or an modified glycosylation pattern. The invention also relates to DNA encoding these phytases, methods of their production, as well as the use thereof, e.g. in animal feed and animal feed additives.