Decolorization of malachite green by cytochrome c in the mitochondria of the fungus Cunninghamella elegans.
We studied the decolorization of malachite green (MG) by the fungus Cunninghamella elegans. The mitochondrial activity for MG reduction was increased with a simultaneous increase of a 9-kDa protein, called CeCyt. The presence of cytochrome c in CeCyt protein was determined by optical absorbance spectroscopy with an extinction coefficient (E(550-535)) of 19.7+/-6.3 mM(-1) cm(-1) and reduction potential of + 261 mV. When purified CeCyt was added into the mitochondria, the specific activity of CeCyt reached 440 +/- 122 micromol min(-1) mg(-1) protein. The inhibition of MG reduction by stigmatellin, but not by antimycin A, indicated a possible linkage of CeCyt activity to the Qo site of the bc1 complex. The RT-PCR results showed tight regulation of the cecyt gene expression by reactive oxygen species. We suggest that CeCyt acts as a protein reductant for MG under oxidative stress in a stationary or secondary growth stage of this fungus.
Kim
Yong-Hak
YH
Functional Proteomics Center, Korea Institute of Science and Technology, Seongbuk, Seoul 136-791, Republic of Korea. yhkim660628@hotmail.com
Lee
Cheolju
C
Go
Hayoung
H
Konishi
Kyoko
K
Lee
Kangseok
K
Lau
Peter C K
PC
Yu
Myeong-Hee
MH
D000595:Amino Acid Sequence; D055162:Biocatalysis; D003116:Color; D020093:Cunninghamella / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D045304:Cytochromes c / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003575:Cytochromes c1 / Q000235:genetics / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012394:Rosaniline Dyes / Q000378:metabolism* / Q000633:toxicity
D012394:Rosaniline Dyes; D009243:NAD; C005095:malachite green; C024757:Coomassie brilliant blue R; D045304:Cytochromes c; D003575:Cytochromes c1