title: A highly stable cambialistic-superoxide dismutase from Antrodia camphorata: expression in yeast and enzyme properties.
abstract: A cDNA encoding a putative superoxide dismutase (SOD) was identified in expressed sequence tags of Antrodia camphorata, a medicinal mushroom found only in Taiwan. The deduced protein was aligned with Mn-SODs and Fe-SODs from other organisms, this SOD showed greater homology to Mn-SOD. Functional A. camphorata SOD protein was overexpressed in yeast and purified. The purified enzyme showed two active forms on a 12.5% native PAGE, a dimer and a monomer. The dimeric protein's half-life of deactivation at 80 degrees C was 7 min, and its thermal inactivation rate constant K(d) was 9.87 x 10(-2)min(-1). The enzyme was stable in a broad pH range from 5-11; in the presence of 0.4M imidazole and 2% SDS. The atomic absorption spectrometric assay showed that 1.0 atom of manganese/iron (9:1) was present in each SOD subunit. The high stability of the enzyme make it better suited than other cambialistic-SODs for use in cosmetics. The SOD also documents its future utility in developing anti-inflammatory agent and in the treatment of chronic diseases.
authors.affiliation: Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Liau
authors.forename: Lisa
authors.initials: L
authors.lastname: Wen
authors.forename: Jei-Fu
authors.initials: JF
authors.lastname: Shaw
authors.forename: Chi-Tsai
authors.initials: CT
authors.lastname: Lin
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D019281:Dimerization; D004795:Enzyme Stability / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000494:pharmacology; D008670:Metals / Q000378:metabolism; D008969:Molecular Sequence Data; D020072:Polyporales / Q000201:enzymology* / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature; D014357:Trypsin / Q000494:pharmacology
chemical_list: D018076:DNA, Complementary; D007093:Imidazoles; D008670:Metals; D013482:Superoxide Dismutase; D014357:Trypsin