Engineering of the alpha-amylase from Geobacillus stearothermophilus US100 for detergent incorporation

Biotechnol Bioeng. 2009 Feb 1;102(2):380-9. doi: 10.1002/bit.22083.

Abstract

AmyUS100DeltaIG is a variant of the most thermoactive and thermostable maltohexaose forming alpha-amylase produced by Geobacillus stearothermophilus sp.US100. This enzyme which was designed to improve the thermostability of the wild-type enzyme has acquired a very high resistance to chelator agents. According to modeling structural studies and with the aim of enhancing its resistance towards chemical oxidation, a mutant (AmyUS100DeltaIG/M197A) was created by substituting methionine 197 to alanine. The catalytic proprieties of the resulting mutant show alterations in the specific activity and the profile of starch hydrolysis. Interestingly, AmyUS100DeltaIG/M197A displayed the highest resistance to oxidation compared to the AmyUS100DeltaIG and to Termamyl300, the well-known commercial amylase used in detergent. Further, performance of the engineered alpha-amylase was estimated in the presence of commonly used detergent compounds and a wide range of commercial detergent (liquid and solid). These studies indicated a high compatibility and performance of AmyUS100DeltaIG/M197A, suggesting its potential application in detergent industry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine / chemistry
  • Alanine / genetics
  • Amino Acid Substitution
  • Bacillus / enzymology*
  • Catalysis
  • Detergents / chemistry*
  • Enzyme Stability / genetics
  • Escherichia coli / genetics
  • Hot Temperature
  • Methionine / chemistry
  • Methionine / genetics
  • Mutagenesis
  • Oligosaccharides / biosynthesis
  • Oxidation-Reduction
  • Protein Conformation
  • Protein Engineering*
  • Structure-Activity Relationship
  • alpha-Amylases / biosynthesis
  • alpha-Amylases / chemistry*
  • alpha-Amylases / genetics*

Substances

  • Detergents
  • Oligosaccharides
  • maltohexaose
  • Methionine
  • alpha-Amylases
  • Alanine