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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-11-2
pubmed:abstractText
A novel thermostable MnSOD was purified to electrophoretic homogeneity from the fungal strain Humicola lutea 110. The preparation of the pure metalloenzyme was performed using treatment with acetone followed by ion exchange and gel permeation chromatography. We found that the activity of this enzyme comprises about 80% of the total superoxide dismutase activity in the crude extract, containing two proteins: MnSOD and Cu/ZnSOD. The MnSOD has a molecular mass of approximately 76 kDa and 7200 U/mg protein specific activity. It is a tetrameric enzyme with four identical subunits of 18 860 Da each as indicated by SDS-PAGE, amino acid analysis and mass spectrometry. N-terminal sequence analysis of MnSOD from the fungal strain revealed a high degree of structural homology with enzymes from other eukaryotic sources. Physicochemical properties were determined by absorption spectroscopy and circular dichroism measurements. The UV absorption spectrum was typical for an MnSOD enzyme, but displayed an increased absorption in the 280 nm region (epsilon280 = 10.4 mM(-1). cm(-1)), attributed to aromatic amino acid residues. The CD data show that MnSOD has two negative Cotton effects at 208 and 222 nm allowing the calculation of its helical content. The ellipticity at 222 nm is 6800 deg. x m(2) x dmol(-1) and thus similar to the values reported for other MnSODs. The MnSOD from H. lutea 110 is stable over a wide range of pH (4.5-8), even in the presence of EDTA. The enzyme is thermostable at 70-75 degrees C, and more stable than MnSODs from other sources.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1397-002X
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
279-89
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Isolation and characterization of a novel superoxide dismutase from fungal strain Humicola lutea 110.
pubmed:affiliation
Institute of Organic Chemistry, Bulgarian Academy of Sciences, Sofia. dolashka@orgchm.bg.acad
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't