首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Cold adapted features of Vibrio salmonicida catalase: characterisation and comparison to the mesophilic counterpart from Proteus mirabilis
Authors:Marit Sjo Lorentzen  Elin Moe  Hélène Marie Jouve  Nils Peder Willassen
Institution:1. Department of Molecular Biotechnology, Faculty of Medicine, Institute of Medical Biology, University of Troms?, 9037, Troms?, Norway
2. The Norwegian Structural Biology Centre (NorStruct), University of Troms?, 9037, Troms?, Norway
3. Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027, Grenoble Cedex 1, France
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 (k cat/K m) compared to PMC. VSC have higher affinity for hydrogen peroxide (apparent K m) at all temperatures. For VSC the turnover rate (k cat) 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                 salmonicida                                Proteus mirabilis                Catalase  Characterisation  Cold adaptation
本文献已被 PubMed SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号