Abstract
Most invertases identified to date have optimal activity at acidic pH, and are intolerant to neutral or alkaline environments. Here, an acid invertase named uninv2 is described. Uninv2 contained 586 amino acids, with a 100 amino acids N-terminal domain, a catalytic domain and a C-terminal domain. With sucrose as the substrate, uninv2 activity was optimal at pH 4.5 and at 45°C. Removal of N-terminal domain of uninv2 has shifted the optimum pH to 6.0 while retaining its optimum temperaure at 45°C. Both uninv2 and the truncated enzyme retained highly stable at neutral pH at 37°C, and they were stable at their optimum pH at 4°C for as long as 30 days. These characteristics make them far superior to invertase from Saccharomyces cerevisiae, which is mostly used as industrial enzyme.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Capnocytophaga / enzymology
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Capnocytophaga / genetics
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Cloning, Molecular
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Enzyme Stability
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Gene Library
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Hydrogen-Ion Concentration
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Kinetics
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Molecular Sequence Data
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Protein Engineering*
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Sequence Deletion*
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Thermotoga maritima / enzymology
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Thermotoga maritima / genetics
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beta-Fructofuranosidase / chemistry
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beta-Fructofuranosidase / genetics*
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beta-Fructofuranosidase / metabolism*
Grants and funding
This work was supported by the National Natural Science Foundation of China (31060125) and the Chinese National Programs for Fundamental Research and Development (2010CB736209). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.