Biochemical characterization of a novel L-Asparaginase with low glutaminase activity from Rhizomucor miehei and its application in food safety and leukemia treatment

Appl Environ Microbiol. 2014 Mar;80(5):1561-9. doi: 10.1128/AEM.03523-13. Epub 2013 Dec 20.

Abstract

A novel fungal gene encoding the Rhizomucor miehei l-asparaginase (RmAsnase) was cloned and expressed in Escherichia coli. Its deduced amino acid sequence shared only 57% identity with the amino acid sequences of other reported l-asparaginases. The purified l-asparaginase homodimer had a molecular mass of 133.7 kDa, a high specific activity of 1,985 U/mg, and very low glutaminase activity. RmAsnase was optimally active at pH 7.0 and 45°C and was stable at this temperature for 30 min. The final level of acrylamide in biscuits and bread was decreased by about 81.6% and 94.2%, respectively, upon treatment with 10 U RmAsnase per mg flour. Moreover, this l-asparaginase was found to potentiate a lectin's induction of leukemic K562 cell apoptosis, allowing lowering of the drug dosage and shortening of the incubation time. Overall, our findings suggest that RmAsnase possesses a remarkable potential for the food industry and in chemotherapeutics for leukemia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / metabolism
  • Apoptosis
  • Asparaginase / chemistry
  • Asparaginase / genetics
  • Asparaginase / isolation & purification
  • Asparaginase / metabolism*
  • Cell Line, Tumor
  • Cell Survival / drug effects*
  • Cloning, Molecular
  • DNA, Fungal / chemistry
  • DNA, Fungal / genetics
  • Enzyme Stability
  • Escherichia coli / genetics
  • Food Safety / methods*
  • Gene Expression
  • Glutaminase / chemistry
  • Glutaminase / genetics
  • Glutaminase / isolation & purification
  • Glutaminase / metabolism*
  • Humans
  • Hydrogen-Ion Concentration
  • Lectins / metabolism
  • Leukemia / therapy*
  • Molecular Sequence Data
  • Molecular Weight
  • Protein Multimerization
  • Rhizomucor / enzymology*
  • Rhizomucor / genetics
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Temperature

Substances

  • Antineoplastic Agents
  • DNA, Fungal
  • Lectins
  • Asparaginase
  • Glutaminase

Associated data

  • GENBANK/KF290772