Extremophiles

, 10:427

Cold adapted features of Vibrio salmonicida catalase: characterisation and comparison to the mesophilic counterpart from Proteus mirabilis

  • Marit Sjo Lorentzen
  • Elin Moe
  • Hélène Marie Jouve
  • Nils Peder Willassen
Original Paper

DOI: 10.1007/s00792-006-0518-z

Cite this article as:
Lorentzen, M.S., Moe, E., Jouve, H.M. et al. Extremophiles (2006) 10: 427. doi:10.1007/s00792-006-0518-z

Abstract

The gene encoding catalase from the psychrophilic marine bacterium Vibrio salmonicida LFI1238 was identified, cloned and expressed in the catalase-deficient Escherichia coli UM2. Recombinant catalase from V. salmonicida (VSC) was purified to apparent homogeneity as a tetramer with a molecular mass of 235 kDa. VSC contained 67% heme b and 25% protoporphyrin IX. VSC was able to bind NADPH, react with cyanide and form compounds I and II as other monofunctional small subunit heme catalases. Amino acid sequence alignment of VSC and catalase from the mesophilic Proteus mirabilis (PMC) revealed 71% identity. As for cold adapted enzymes in general, VSC possessed a lower temperature optimum and higher catalytic efficiency (kcat/Km) compared to PMC. VSC have higher affinity for hydrogen peroxide (apparent Km) at all temperatures. For VSC the turnover rate (kcat) is slightly lower while the catalytic efficiency is slightly higher compared to PMC over the temperature range measured, except at 4°C. Moreover, the catalytic efficiency of VSC and PMC is almost temperature independent, except at 4°C where PMC has a twofold lower efficiency compared to VSC. This may indicate that VSC has evolved to maintain a high efficiency at low temperatures.

Keywords

Vibrio salmonicidaProteus mirabilisCatalaseCharacterisationCold adaptation

Abbreviations

VSC

Vibrio salmonicida catalase

PMC

Proteus mirabilis catalase

Rz

A405 nm/A280 nm, Reinheitszahl index

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Marit Sjo Lorentzen
    • 1
  • Elin Moe
    • 2
  • Hélène Marie Jouve
    • 3
  • Nils Peder Willassen
    • 1
    • 2
  1. 1.Department of Molecular Biotechnology, Faculty of MedicineInstitute of Medical Biology, University of TromsøTromsøNorway
  2. 2.The Norwegian Structural Biology Centre (NorStruct)University of TromsøTromsøNorway
  3. 3.Institut de Biologie StructuraleGrenoble Cedex 1France