Isolation and biochemical characterization of a glucose dehydrogenase from a hay infusion metagenome

PLoS One. 2014 Jan 14;9(1):e85844. doi: 10.1371/journal.pone.0085844. eCollection 2014.

Abstract

Glucose hydrolyzing enzymes are essential to determine blood glucose level. A high-throughput screening approach was established to identify NAD(P)-dependent glucose dehydrogenases for the application in test stripes and the respective blood glucose meters. In the current report a glucose hydrolyzing enzyme, derived from a metagenomic library by expressing recombinant DNA fragments isolated from hay infusion, was characterized. The recombinant clone showing activity on glucose as substrate exhibited an open reading frame of 987 bp encoding for a peptide of 328 amino acids. The isolated enzyme showed typical sequence motifs of short-chain-dehydrogenases using NAD(P) as a co-factor and had a sequence similarity between 33 and 35% to characterized glucose dehydrogenases from different Bacillus species. The identified glucose dehydrogenase gene was expressed in E. coli, purified and subsequently characterized. The enzyme, belonging to the superfamily of short-chain dehydrogenases, shows a broad substrate range with a high affinity to glucose, xylose and glucose-6-phosphate. Due to its ability to be strongly associated with its cofactor NAD(P), the enzyme is able to directly transfer electrons from glucose oxidation to external electron acceptors by regenerating the cofactor while being still associated to the protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Enzyme Stability
  • Escherichia coli / genetics
  • Glucose / metabolism
  • Glucose 1-Dehydrogenase / chemistry
  • Glucose 1-Dehydrogenase / genetics
  • Glucose 1-Dehydrogenase / isolation & purification*
  • Glucose 1-Dehydrogenase / metabolism*
  • Hydrolysis
  • Kinetics
  • Metagenome*
  • Molecular Sequence Data
  • Poaceae / microbiology*
  • Poaceae / parasitology
  • Sequence Analysis
  • Substrate Specificity
  • Temperature

Substances

  • Glucose 1-Dehydrogenase
  • Glucose

Grants and funding

The project was funded by the Hamburg University of Technology. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.