Related Experiment Video
Updated: May 8, 2026
Methods to Increase the Sensitivity of High Resolution Melting Single Nucleotide Polymorphism Genotyping in Malaria
Published on: November 10, 2015
Thermostability improvement of maltogenic amylase MAUS149 by error prone PCR
Sameh Ben Mabrouk1, Dorra Zouari Ayadi, Hajer Ben Hlima
1Laboratoire d'Enzymes et de Métabolites des Procaryotes, Centre de Biotechnologie de Sfax, Université de Sfax, BP "1177", 3018 Sfax, Tunisia.
Abstract:
The thermostability of maltogenic amylase from Bacillus sp. US149 (MAUS149) was improved by random mutagenesis using error prone PCR. The library constructed for the mutants obtained was subjected to screening, leading to the selection of a thermostable mutant enzyme named MA-A27. The latter was noted to contain four single mutations, namely D46V, P78L, V145A, and K548E. The half-life times recorded for MA-A27 at 50°C and 55°C were 70 min and 25 min, compared to 30 min and 13 min for the wild type, respectively. The results from molecular modeling attributed the increase in thermostability observed for MA-A27 to P78L and K548E substitutions that led to new hydrogen bond and salt bridge formations. Further site-directed mutagenesis studies showed that the P78L and K548E single mutations underwent an increase in thermostability, thus confirming the joint contribution of both substitutions to the increase in thermostability observed for MA-A27.
Insights
This study enhanced the heat stability of maltogenic amylase using random mutagenesis. A selected mutant, MA-A27, showed significantly improved enzyme performance at higher temperatures.
Area of Science:
- Enzymology
- Protein Engineering
- Biotechnology
Background:
- Maltogenic amylase is crucial for various industrial applications.
- Improving enzyme thermostability enhances process efficiency and reduces costs.
- Bacillus sp. US149 maltogenic amylase (MAUS149) is a target for protein engineering.
Purpose of the Study:
- To enhance the thermostability of maltogenic amylase from Bacillus sp. US149.
- To identify specific mutations responsible for increased thermal stability.
- To understand the molecular basis of enhanced enzyme performance.
Main Methods:
- Random mutagenesis using error-prone PCR to create a mutant library.
- Screening of mutants to identify thermostable variants.
- Molecular modeling and site-directed mutagenesis to analyze mutation effects.
Main Results:
- A thermostable mutant, MA-A27, was selected, exhibiting four mutations: D46V, P78L, V145A, and K548E.
- MA-A27 showed a 2-fold increase in half-life at 50°C and 55°C compared to the wild type.
- Molecular modeling indicated P78L and K548E substitutions contribute to enhanced stability via new hydrogen bonds and salt bridges.
Conclusions:
- The P78L and K548E mutations are key contributors to the enhanced thermostability of MA-A27.
- Site-directed mutagenesis confirmed the synergistic effect of these mutations on enzyme stability.
- Engineered maltogenic amylase variants hold promise for industrial applications requiring high-temperature enzyme activity.
Related Concept Videos
01:32PCR
01:20Mismatch Repair
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...