Functional expression and characterization of a chitinase from the marine archaeon Halobacterium salinarum CECT 395 in Escherichia coli

Appl Microbiol Biotechnol. 2014 Mar;98(5):2133-43. doi: 10.1007/s00253-013-5124-2. Epub 2013 Jul 30.

Abstract

The HschiA1 gene of the archaeon Halobacterium salinarum CECT 395 was cloned and overexpressed as an active protein of 66.5 kDa in Escherichia coli. The protein called HsChiA1p has a modular structure consisting of a glycosyl hydrolase family 18 catalytic region, as well as a N-terminal family 5 carbohydrate-binding module and a polycystic kidney domain. The purified recombinant chitinase displayed optimum catalytic activity at pH 7.3 and 40 °C and showed high stability over broad pH (6-8.5) and temperature (25-45 °C) ranges. Protein activity was stimulated by the metal ions Mg(+2), K(+), and Ca(+2) and strongly inhibited by Mn(+2). HsChiA1p is salt-dependent with its highest activity in the presence of 1.5 M of NaCl, but retains 20% of its activity in the absence of salt. The recombinant enzyme hydrolysed p-NP-(GlcNAc)3, p-NP-(GlcNAc), crystalline chitin, and colloidal chitin. From its sequence features and biochemical properties, it can be identified as an exo-acting enzyme with potential interest regarding the biodegradation of chitin waste or its bioconversion into biologically active products.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aquatic Organisms / enzymology*
  • Aquatic Organisms / genetics
  • Chitinases / chemistry
  • Chitinases / genetics
  • Chitinases / isolation & purification
  • Chitinases / metabolism*
  • Cloning, Molecular
  • Enzyme Activators / metabolism
  • Enzyme Inhibitors / metabolism
  • Enzyme Stability
  • Escherichia coli / genetics
  • Gene Expression
  • Halobacterium salinarum / enzymology*
  • Halobacterium salinarum / genetics
  • Hydrogen-Ion Concentration
  • Ions / metabolism
  • Metals / metabolism
  • Molecular Weight
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sodium Chloride / metabolism
  • Substrate Specificity
  • Temperature

Substances

  • Enzyme Activators
  • Enzyme Inhibitors
  • Ions
  • Metals
  • Recombinant Proteins
  • Sodium Chloride
  • Chitinases