Characterization of Cryptopygus antarcticus endo-β-1,4-glucanase from Bombyx mori expression systems

Mol Biotechnol. 2014 Oct;56(10):878-89. doi: 10.1007/s12033-014-9767-8.

Abstract

Endo-β-1,4-glucanase (CaCel) from Antarctic springtail, Cryptopygus antarcticus, a cellulase with high activity at low temperature, shows potential industrial use. To obtain sufficient active cellulase for characterization, CaCel gene was expressed in Bombyx mori-baculovirus expression systems. Recombinant CaCel (rCaCel) has been expressed in Escherichia coli (Ec-CaCel) at temperatures below 10°C, but the expression yield was low. Here, rCaCel with a silkworm secretion signal (Bm-CaCel) was successfully expressed and secreted into pupal hemolymph and purified to near 90% purity by Ni-affinity chromatography. The yield and specific activity of rCaCel purified from B. mori were estimated at 31 mg/l and 43.2 U/mg, respectively, which is significantly higher than the CaCel yield obtained from E. coli (0.46 mg/l and 35.8 U/mg). The optimal pH and temperature for the rCaCels purified from E. coli and B. mori were 3.5 and 50°C. Both rCaCels were active at a broad range of pH values and temperatures, and retained more than 30% of their maximal activity at 0°C. Oligosaccharide structural analysis revealed that Bm-CaCel contains elaborated N- and O-linked glycans, whereas Ec-CaCel contains putative O-linked glycans. Thermostability of Bm-CaCel from B. mori at 60°C was higher than that from E. coli, probably due to glycosylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arthropods / enzymology*
  • Bombyx / metabolism*
  • Cellulase / chemistry
  • Cellulase / metabolism*
  • Escherichia coli / metabolism
  • Gene Expression*
  • Glycosylation
  • Hydrogen-Ion Concentration
  • Molecular Sequence Data
  • Plant Lectins / metabolism
  • Polysaccharides / chemistry
  • Pupa / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / isolation & purification
  • Temperature

Substances

  • Plant Lectins
  • Polysaccharides
  • Recombinant Proteins
  • Cellulase