Abstract:
:Ribonucleotide reductases catalyze the irreversible reductive formation of 2'-deoxyribonucleotides required for DNA replication and cell proliferation, and a radical mechanism was assumed to be involved in this reaction. In order to search for a radical in the aerobic manganese ribonucleotide reductase (Mn-RRase) by electron paramagnetic resonance (EPR) the native metal-containing 100 kDa B2 subunit was deliberately prepared from the wild type strain Corynebacterium ammoniagenes ATCC 6872. Enrichment by 2'5'-ADP Sepharose 4B affinity chromatography, fast protein liquid chromatography (FPLC) with SuperoseTM12 and concentration by vacuum evaporation allowed for the first time the detection of a stable free radical by EPR spectroscopy at 77 K. The EPR spectrum exhibits an easily saturable doublet of 1.8 mT splitting and a line width of 1.3 mT at g = 2.0040. The EPR signal intensity showed a clear correlation with the enzymatic activity upon long-time storage at ambient temperature (294 K) and inactivation by the specific RRase inhibitor hydroxyurea (HU). This leads to the assumption of a protein-linked radical, with functional significance, in the metal-containing 100 kDa B2 subunit of the MnRRase of Corynebacterium ammoniagenes.
journal_name
Free Radic Resjournal_title
Free radical researchauthors
Griepenburg U,Lassmann G,Auling Gdoi
10.3109/10715769609088046subject
Has Abstractpub_date
1996-06-01 00:00:00pages
473-81issue
6eissn
1071-5762issn
1029-2470journal_volume
24pub_type
杂志文章abstract::Globular adiponectin (gAd) induces the generation of reactive oxygen species (ROS) and nitric oxide (NO) in the murine macrophage cell line RAW 264. This study investigated the role of the mammalian target of rapamycin (mTOR) in gAd-induced ROS and NO generation. gAd stimulation induced phosphorylation of mTOR, which ...
journal_title:Free radical research
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journal_title:Free radical research
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journal_title:Free radical research
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journal_title:Free radical research
pub_type: 杂志文章,评审
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journal_title:Free radical research
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pub_type: 临床试验,杂志文章
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journal_title:Free radical research
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journal_title:Free radical research
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更新日期:2017-12-01 00:00:00
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