Abstract：
:The conversion of specific proteins or protein fragments into insoluble, ordered fibrillar aggregates is a fundamental process in protein chemistry, biology, medicine and biotechnology. As this structural conversion seems to be a property shared by many proteins, understanding the mechanism of this process will be of extreme importance. Here we present a structural characterisation of a conformational state populated at low pH by the N-terminal domain of Escherichia coli HypF. Combining different biophysical and biochemical techniques, including near- and far-UV circular dichroism, intrinsic and 8-anilinonaphthalene-1-sulfonate-derived fluorescence, dynamic light scattering and limited proteolysis, we will show that this state is largely unfolded but contains significant secondary structure and hydrophobic clusters. It also appears to be more compact than a random coil-like state but less organised than a molten globule state. Increase of the total ionic strength of the solution induces aggregation of such a pre-molten globule state into amyloid-like protofibrils, as revealed by thioflavin T fluorescence and atomic force microscopy. These results show that a pre-molten globule state can be, among other possible conformational states, one of the precursor states of amyloid formation. In addition, the possibility of triggering aggregation by modulating the ionic strength of the solution provides one a unique opportunity to study both the initial precursor state and the aggregation process.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Campioni S,Mossuto MF,Torrassa S,Calloni G,de Laureto PP,Relini A,Fontana A,Chiti Fdoi
10.1016/j.jmb.2008.04.002subject
Has Abstractpub_date
2008-06-06 00:00:00pages
554-67issue
3eissn
0022-2836issn
1089-8638pii
S0022-2836(08)00409-9journal_volume
379pub_type
杂志文章abstract：:6,7-Dimethyl-8-ribityllumazine synthase (lumazine synthase) catalyses the penultimate step in the biosynthesis of riboflavin. In Bacillus subtilis, 60 lumazine synthase subunits form an icosahedral capsid enclosing a homotrimeric riboflavin synthase unit. The ribH gene specifying the lumazine synthase subunit can be e...
journal_title：Journal of molecular biology
pub_type： 杂志文章
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abstract：:The time-course of synthesis of long and short (abortive) transcripts by Escherichia coli RNA polymerase was investigated under single round conditions in vitro. The synthesis of long RNA initiated at the lambda PR (with an altered leader sequence) or at the lacUV5 promoter was completed within five minutes, but abort...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1996.0100
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1996.0232
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.2000.4269
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pub_type： 杂志文章
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.2001.5117
更新日期：2001-11-16 00:00:00
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pub_type： 杂志文章
doi：10.1006/jmbi.2000.4037
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journal_title：Journal of molecular biology
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doi：10.1016/j.jmb.2004.12.003
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(89)90242-8
更新日期：1989-06-20 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1993.1416
更新日期：1993-07-20 00:00:00
abstract：:The molecular structure of the high-potential iron-sulfur protein (HiPIP) isolated from the phototrophic bacterium, Rhodocyclus tenuis, has been solved and refined to a nominal resolution of 1.5 A with a crystallographic R-factor of 17.3% for all measured X-ray data from 30 A to 1.5 A. It is the smallest of the HiPIP ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1016/0022-2836(92)90849-f
更新日期：1992-11-20 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
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abstract：:The crystal structure of the staphylococcal nuclease mutant V66K, in which valine 66 is replaced by lysine, has been solved at 1.97 A resolution. Unlike lysine residues in previously reported protein structures, this residue appears to bury its side-chain in the hydrophobic core without salt bridging, hydrogen bonding...
journal_title：Journal of molecular biology
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journal_title：Journal of molecular biology
pub_type： 杂志文章
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更新日期：1998-04-17 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1994.0120
更新日期：1995-03-17 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1996.0320
更新日期：1996-06-07 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
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更新日期：1994-04-22 00:00:00
abstract：:Syk is an essential non-receptor tyrosine kinase in intracellular immunological signaling, and the control of Syk kinase function is considered as a valuable target for pharmacological intervention in autoimmune or inflammation diseases. Upon immune receptor stimulation, the kinase activity of Syk is regulated by bind...
journal_title：Journal of molecular biology
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doi：10.1016/j.jmb.2012.11.007
更新日期：2013-01-23 00:00:00
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journal_title：Journal of molecular biology
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更新日期：2018-09-14 00:00:00
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journal_title：Journal of molecular biology
pub_type： 杂志文章
doi：10.1006/jmbi.1998.1871
更新日期：1998-07-10 00:00:00
abstract：:Physarum polycephalum hemagglutinin I (HA1) is a 104-residue protein that is secreted to extracellular space. The crystal structure of HA1 has a β-sandwich fold found among lectin structures, such as legume lectins and galectins. Interestingly, the β-sandwich of HA1 lacks a jelly roll motif and is essentially composed...
journal_title：Journal of molecular biology
pub_type： 杂志文章
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abstract：:The Spo0A protein of Bacillus subtilis is a transcriptional regulator that shows extensive homology to the regulator proteins in bacterial two-component regulatory systems. Phosphorylation of Spo0A is absolutely necessary for the initiation of sporulation. We now show that phospho-Spo0A is a dimer, binds specifically ...
journal_title：Journal of molecular biology
pub_type： 杂志文章
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更新日期：1995-06-30 00:00:00
