FOOD SCIENCE ›› 2017, Vol. 38 ›› Issue (2): 46-51.doi: 10.7506/spkx1002-6630-201702008

• Bioengineering • Previous Articles     Next Articles

Gene Cloning, Expression and Functional Charaterization of NAD(P)H Oxidases Gene (nox) from Listeria monoeytogenes

WU Man, LI Sen, CHEN Guowei, LUO Qin, LIU Wukang, DING Chengchao, DONG Qingli, LIU Qing   

  1. 1. School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; 2. College of Life Sciences, Central China Normal University, Wuhan 430079, China
  • Online:2017-01-25 Published:2017-01-16

Abstract: Nicotinamide adenine dinucleotide phosphate oxidases (Nox) is ubiquitous in higher animals and plants, and it is responsible for generating reactive oxygen species (ROS). The aim of this work was to explore whether the NOX mediates the generation of ROS in Listeria monocytogenes (Lm). The nox gene from the wild-type Listeria monocytogenes EGDe (GenBank ID: 986631) was tested. The gene was induced to express Nox in Escherichia coli BL21 and the molecular weight of the expressed enzyme was measured by using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. Then the over-expressed strain EGDe-nox was built to detect ROS production and examine the influence of nox gene over-expression on the expression of virulence genes by using quantitative real-time polymerase chain reaction (qRT-qPCR). The results showed that the molecular weight of the recombinant Nox was about 33 kD. Compared with EGDe, the ROS production of EGDe-nox was not changed significantly. The over-expression of nox resulted in up-regulated expression of the invasion-related genes actA, inlA and inlB and the virulence gene prfA. These results suggest that the Nox is unable to dominate ROS production independently but its over-expression can up-regulate the expression of virulence genes.

Key words: Listeria monocytogenes, NADH oxidase, nox, reactive oxygen species (ROS)

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