African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

Purification and properties of a non-stereospecific dehalogenase enzyme E (DehE) from Methylobacterium sp. HJ1

Ng Hong Jing1, Fatin Hanani Sulaiman1, Roswanira Ab. Wahab2, Rolando V. Pakinging Jr3,  Noor Aini Abdul Rashid1 and Fahrul Huyop1*
1Industrial Biotechnology Department, Faculty of Biosciences and Bioengineering, University Technology Malaysia, 81310 Skudai, Johor, Malaysia. 2Chemistry Department, Faculty of Science, University Technology Malaysia, 81310 Skudai, Johor, Malaysia. 3SouthEast Asian Fisheries Development Center Aquaculture Department, Tigbauan, Iloilo, 5021 Philippines.
Email: [email protected]

  •  Accepted: 12 June 2008
  •  Published: 31 July 2008

Abstract

The bacterial isolate HJ1, which was identified as a Methylobacterium sp., grew on 2, 2-dichloropropionic acid as the sole carbon source and produced a 2-haloalkanoic acid hydrolytic dehalogenase. This non-stereospecific dehalogenase E (DehE) catalysed the hydrolytic dechlorination of 2, 2-dichloropropionic acid and D, L-2-chloropropionic acid to produce pyruvate and lactate, respectively. The enzyme was purified to homogeneity and characterized.  The molecular weight was 36 kDa by SDS-polyacrylamide gel electrophoresis and 72 kDa by gel filtration, suggesting that the enzyme is a protein dimer.  The purified enzyme was only inhibited by HgSO4 and was non-stereospecific to haloalkanoic acids.  The Km value for the hydrolysis of 2, 2-dichloropropionic acid was 0.25 mM. The enzyme removes chloride present on the α-position, but not on the β-position, of a number 2–carbon alkanoic acids.

 

Key words: Haloalkanoic acid, dichloropropionate, 2, 2-dichloropropionic acid.