A thermostable laccase from Streptomyces lavendulae REN-7: purification, characterization, nucleotide sequence, and expression

Biosci Biotechnol Biochem. 2003 Oct;67(10):2167-75. doi: 10.1271/bbb.67.2167.


We found a polyphenoloxidase (PPO) in the cell extract of Streptomyces lavendulae REN-7. About 0.8 mg of purified PPO was obtained from 200 g of the mycelia with a yield of 9.0%. REN-7-PPO showed broad substrate specificity toward various aromatic compounds. Moreover, this enzyme was capable of oxidation of syringaldazine, which is a specific substrate for laccase. Interestingly, REN-7-PPO retained its original activity after 20 min of incubation at even 70 degrees C. The gene encoding the PPO was cloned. Four copper-binding sites characteristics of laccases were contained in the deduced amino acid sequence. We constructed a high-level expression system of this gene in Escherichia coli. The properties of the recombinant enzyme were identical that of wild-type. In conclusion, this PPO is a thermostable laccase.

MeSH terms

  • Base Sequence
  • Catechol Oxidase
  • Enzyme Stability
  • Escherichia coli / genetics
  • Hydrazones / metabolism
  • Laccase / chemistry
  • Laccase / genetics*
  • Laccase / isolation & purification*
  • Molecular Sequence Data
  • Streptomyces / enzymology*
  • Substrate Specificity
  • Temperature


  • Hydrazones
  • syringaldazine
  • Catechol Oxidase
  • Laccase