Characterisation of 2-Cys peroxiredoxin isozyme (Prx1) from Taiwanofungus camphorata (Niu-chang-chih): Expression and enzyme properties

摘要

Peroxiredoxins (Prxs) are a family of antioxidant peroxidases. The functions of Prxs comprises of cell protection against oxidative stress and regulation of cell proliferation. A putative 2-Cys Prx isozyme (Prxl) cDNA was cloned from Taiwanofungus camphorata (commonly known as Niu-chang-chih in Taiwan). The deduced amino acid sequence is conserved amongst the reported Prxs. A 3-D homology structure was created for this Prx1. To characterise the T. camphorata Prxl, the coding region was subcloned into a pAVD10 and transformed into Escherichia coli. The recombinant 6His-tagged Prx1 was expressed and purified by Ni~(2+)-nitrilotriacetic acid sepharose. The purified enzyme showed two forms using a 15% SDS-PAGE. The enzyme retained 60% activity at 60 ℃ for 2.5 min. The enzyme was stable under a broad pH range from 5 to 11. The enzyme showed 57% activity after 40 min of incubation at 37 ℃ with trypsin. The ability of the enzyme to protect intact supercoiled plasmid DNA from OH induced nicking was demonstrated.