[Properties of a triphenylmethane dyes decolorization enzyme (TpmD) from Aeromonas hydrophila strain DN322].
A novel bacterial enzyme for decolorization of triphenylmethane dyes from Aeromonas hydrophila strain DN322 was purified and named TpmD. The basic properties of this enzyme including molecular weight, isoelectric point Km as well as the optimum temperature and pH were determined and the enzyme was identified as an NADH/NADPH-dependent oxygenase in previous research. Based on previous results, the effect of different inhibitor including Vc, metyrapone, rotenone, antimycin A and NaN3 as well as the effect of FAD and FMN on the activity of TpmD were measured. The results indicated that the activity of the decolorization enzyme was inhibited by Vc and metyrapone in a concentration-dependent manner, but wasn't inhibited by rotenone, antimycin A and NaN3. The activity of the decolorization enzyme was not enhanced by addition of FAD or FMN. The solution of the enzyme protein displayed only a single peak at 408nm in the Soret region, a characteristic peak of porphyrin, but did not show the characteristic peak of the cytochrome P450 proteins at 450nm in sodium dithionite (DTN)-reduced enzyme solution after treatment with carbon monoxide. The amino acid sequence of N-terminal of TpmD provided further evidence that the enzyme is an oxygenase. All these results suggest that decolorization enzyme TpmD is a new hemo-containing oxygenase. The decolorization enzyme would be a good material for further research of the enzymological mechanism of triphenylmethane dyes decolorization by bacteria.
Ren
Sui-Zhou
SZ
Guangdong Institute of Microbiology, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou 510070, China. rensz@163.com
Guo
Jun
J
Cen
Ying-Hua
YH
Sun
Guo-Ping
GP
D016980:Aeromonas hydrophila / Q000201:enzymology*; D000595:Amino Acid Sequence; D001205:Ascorbic Acid / Q000494:pharmacology; D001673:Biodegradation, Environmental; D003116:Color; D004396:Coloring Agents / Q000378:metabolism*; D008797:Metyrapone / Q000494:pharmacology; D010105:Oxygenases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D014320:Triphenylmethyl Compounds / Q000378:metabolism*
D004396:Coloring Agents; D014320:Triphenylmethyl Compounds; C046945:triphenylmethane; D010105:Oxygenases; D001205:Ascorbic Acid; D008797:Metyrapone