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[Mechanism of arginine deiminase activity by site-directed mutagenesis]

Lifeng Li1, Ye Ni, Zhihao Sun

  • 1Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China.

Sheng Wu Gong Cheng Xue Bao = Chinese Journal of Biotechnology
|July 19, 2012
PubMed

Insights

Arginine deiminase (ADI) mutations enhance its anti-cancer properties. Specific mutations improve ADI

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Enzymology

Background:

  • Arginine deiminase (ADI) is investigated as a cancer therapeutic for arginine-auxotrophic tumors.
  • Understanding ADI's molecular mechanism is crucial for optimizing its anti-cancer efficacy.

Purpose of the Study:

  • To elucidate the molecular mechanism of arginine deiminase (ADI) activity.
  • To engineer improved ADI variants through site-directed mutagenesis for enhanced anti-cancer potential.

Main Methods:

  • Site-directed mutagenesis was employed to introduce mutations at sites A128, H404, and I410 in the wild-type ADI gene.
  • Four ADI mutants (M1, M2, M3, M4) were generated and expressed in Escherichia coli.
  • Enzymatic properties of purified mutant proteins were analyzed.

Main Results:

  • Mutations A128T and H404R resulted in enhanced optimal pH and increased ADI activity and stability at physiological pH (7.4).
  • These mutations also led to a reduced K(m) value, indicating improved substrate binding.
  • Mutant M4 (A128T, H404R) combined beneficial effects.

Conclusions:

  • The study provides insights into the molecular mechanisms governing ADI activity.
  • Specific mutations can rationally enhance ADI's enzymatic properties for potential therapeutic applications.
  • This work offers experimental evidence supporting protein evolution strategies for developing improved ADI-based cancer therapies.

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