Linear three-iron centres are unlikely cluster degradation intermediates during unfolding of iron-sulfur proteins
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Sónia S. Leal
Abstract
Recent studies on the chemical alkaline degradation of ferredoxins have contributed to the hypothesis that linear three-iron centres are commonly observed as degradation intermediates of iron-sulfur clusters. In this work we assess the validity of this hypothesis. We studied different proteins containing iron-sulfur clusters, iron-sulfur centres and di-iron centres with respect to their chemical degradation kinetics at high pH, in the presence and absence of exogenous sulfide, to investigate the possible formation of linear three-iron centres during protein unfolding. Our spectroscopic and kinetic data show that in these different proteins visible absorption bands at 530 and 620 nm are formed that are identical to those suggested to arise from linear three-iron centres. Iron release and protein unfolding kinetics show that these bands result from the formation of iron sulfides at pH 10, produced by the degradation of the iron centres, and not from rearrangements leading to linear three-iron centres. Thus, at this point any relevant functional role of linear three-iron centres as cluster degradation intermediates in iron-sulfur proteins remains elusive.
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©2005 by Walter de Gruyter Berlin New York
Artikel in diesem Heft
- Highlight: RNA Biochemistry
- microRNA-guided posttranscriptional gene regulation
- How to find small non-coding RNAs in bacteria
- Species-specific antibiotic-ribosome interactions: implications for drug development
- The tRNase Z family of proteins: physiological functions, substrate specificity and structural properties
- Alternative pre-mRNA splicing in the human system: unexpected role of repetitive sequences as regulatory elements
- 6S RNA – an ancient regulator of bacterial RNA polymerase rediscovered
- RNA thermometers are common in α- and γ-proteobacteria
- Inhibition of mRNA deadenylation and degradation by ultraviolet light
- Linear three-iron centres are unlikely cluster degradation intermediates during unfolding of iron-sulfur proteins
- Trypsin inhibition by macrocyclic and open-chain variants of the squash inhibitor MCoTI-II
- Structural properties of substrate proteins determine their proteolysis by the mitochondrial AAA+ protease Pim1
- Inhibitory plant serpins with a sequence of three glutamine residues in the reactive center
- Inhibition of cathepsin B reduces β-amyloid production in regulated secretory vesicles of neuronal chromaffin cells: evidence for cathepsin B as a candidate β-secretase of Alzheimer's disease
- Acknowledgement
- Contents Biological Chemistry Volume 386, 2005
- Author Index
- Subject Index
Artikel in diesem Heft
- Highlight: RNA Biochemistry
- microRNA-guided posttranscriptional gene regulation
- How to find small non-coding RNAs in bacteria
- Species-specific antibiotic-ribosome interactions: implications for drug development
- The tRNase Z family of proteins: physiological functions, substrate specificity and structural properties
- Alternative pre-mRNA splicing in the human system: unexpected role of repetitive sequences as regulatory elements
- 6S RNA – an ancient regulator of bacterial RNA polymerase rediscovered
- RNA thermometers are common in α- and γ-proteobacteria
- Inhibition of mRNA deadenylation and degradation by ultraviolet light
- Linear three-iron centres are unlikely cluster degradation intermediates during unfolding of iron-sulfur proteins
- Trypsin inhibition by macrocyclic and open-chain variants of the squash inhibitor MCoTI-II
- Structural properties of substrate proteins determine their proteolysis by the mitochondrial AAA+ protease Pim1
- Inhibitory plant serpins with a sequence of three glutamine residues in the reactive center
- Inhibition of cathepsin B reduces β-amyloid production in regulated secretory vesicles of neuronal chromaffin cells: evidence for cathepsin B as a candidate β-secretase of Alzheimer's disease
- Acknowledgement
- Contents Biological Chemistry Volume 386, 2005
- Author Index
- Subject Index