Molecular characterization and expression of a novel alcohol oxidase from Aspergillus terreus MTCC6324

PLoS One. 2014 Apr 21;9(4):e95368. doi: 10.1371/journal.pone.0095368. eCollection 2014.

Abstract

The alcohol oxidase (AOx) cDNA from Aspergillus terreus MTCC6324 with an open reading frame (ORF) of 2001 bp was constructed from n-hexadecane induced cells and expressed in Escherichia coli with a yield of ∼4.2 mg protein g-1 wet cell. The deduced amino acid sequences of recombinant rAOx showed maximum structural homology with the chain B of aryl AOx from Pleurotus eryngii. A functionally active AOx was achieved by incubating the apo-AOx with flavin adenine dinucleotide (FAD) for ∼80 h at 16°C and pH 9.0. The isoelectric point and mass of the apo-AOx were found to be 6.5±0.1 and ∼74 kDa, respectively. Circular dichroism data of the rAOx confirmed its ordered structure. Docking studies with an ab-initio protein model demonstrated the presence of a conserved FAD binding domain with an active substrate binding site. The rAOx was specific for aryl alcohols and the order of its substrate preference was 4-methoxybenzyl alcohol >3-methoxybenzyl alcohol>3, 4-dimethoxybenzyl alcohol > benzyl alcohol. A significantly high aggregation to ∼1000 nm (diameter) and catalytic efficiency (kcat/Km) of 7829.5 min-1 mM-1 for 4-methoxybenzyl alcohol was also demonstrated for rAOx. The results infer the novelty of the AOx and its potential biocatalytic application.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Oxidoreductases / chemistry
  • Alcohol Oxidoreductases / genetics*
  • Alcohol Oxidoreductases / isolation & purification
  • Alcohol Oxidoreductases / metabolism
  • Alcohols / metabolism
  • Amino Acid Sequence
  • Aspergillus / enzymology*
  • Aspergillus / genetics
  • Base Sequence
  • Biophysical Phenomena
  • Circular Dichroism
  • DNA, Complementary / genetics
  • Electrophoresis, Gel, Two-Dimensional
  • Enzyme Stability
  • Flavin-Adenine Dinucleotide / metabolism
  • Gene Amplification
  • Hydrogen-Ion Concentration
  • Kinetics
  • Light
  • Microsomes / metabolism
  • Molecular Docking Simulation
  • Molecular Sequence Data
  • Peptide Mapping
  • Peptides / chemistry
  • Proteomics
  • Recombinant Proteins / metabolism
  • Scattering, Radiation
  • Spectrometry, Fluorescence
  • Substrate Specificity
  • Temperature

Substances

  • Alcohols
  • DNA, Complementary
  • Peptides
  • Recombinant Proteins
  • Flavin-Adenine Dinucleotide
  • Alcohol Oxidoreductases
  • alcohol oxidase

Grants and funding

Department of Biotechnology, India. URL: http://dbtindia.nic.in/index.asp. Sanction order No. BT/01/NE/PS/08 Project -III. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.