Cloning, expression and characterization of a novel thermophilic polygalacturonase from Caldicellulosiruptor bescii DSM 6725

Int J Mol Sci. 2014 Apr 3;15(4):5717-29. doi: 10.3390/ijms15045717.

Abstract

We cloned the gene ACM61449 from anaerobic, thermophilic Caldicellulosiruptor bescii, and expressed it in Escherichia coli origami (DE3). After purification through thermal treatment and Ni-NTA agarose column extraction, we characterized the properties of the recombinant protein (CbPelA). The optimal temperature and pH of the protein were 72 °C and 5.2, respectively. CbPelA demonstrated high thermal-stability, with a half-life of 14 h at 70 °C. CbPelA also showed very high activity for polygalacturonic acid (PGA), and released monogalacturonic acid as its sole product. The Vmax and Km of CbPelA were 384.6 U·mg⁻¹ and 0.31 mg·mL⁻¹, respectively. CbPelA was also able to hydrolyze methylated pectin (48% and 10% relative activity on 20%-34% and 85% methylated pectin, respectively). The high thermo-activity and methylated pectin hydrolization activity of CbPelA suggest that it has potential applications in the food and textile industry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Gram-Positive Endospore-Forming Rods / enzymology*
  • Gram-Positive Endospore-Forming Rods / genetics*
  • Gram-Positive Endospore-Forming Rods / metabolism
  • Hot Temperature
  • Pectins / metabolism
  • Polygalacturonase / genetics*
  • Sequence Alignment

Substances

  • Bacterial Proteins
  • Pectins
  • Polygalacturonase