Publication date: Available online 11 May 2017 Source:Journal of Molecular Biology
Author(s): Ishita Sengupta, Suhas H. Bhate, Ranabir Das, Jayant B. Udgaonkar
The prion protein forms ß-rich soluble oligomers in vitro at pH4 in the presence of physiological concentrations of salt. In the absence of salt, oligomerization and misfolding does not take place in an experimentally tractable timescale. While it is well established that a lowering of pH facilitates misfolding and oligomerization of this protein, the role of salt remains poorly understood. Here, solution-state NMR was used to probe perturbations in the monomeric mouse prion protein moPrP) structure immediately upon salt-addition, prior to the commencement of the oligomerization reaction. The weak binding of salt at multiple sites dispersed all over the monomeric protein causes a weak non-specific perturbation of structure throughout the protein. The only significant perturbation occurs in the loop between helix 2 and 3 in and around the partially buried K193-E195 salt bridge. The disruption of this key electrostatic interaction is the earliest detectable change in the monomer before any major conformational change occurs and appears to constitute the trigger for the commencement of misfolding and oligomerization. Subsequently, the kinetics of monomer loss, due to oligomerization, was monitored at the individual residue level. The oligomerization reaction was found to be rate-limited by association and not conformational change, with an average reaction order of 2.6, across residues. Not surprisingly, salt accelerated the oligomerization kinetics, in a non-specific manner, by electrostatic screening of the highly charged monomers at acidic pH. Together, these results allowed a demarcation of the specific and non-specific effects of salt on prion protein misfolding and oligomerization. Graphical abstract
[NMR paper] Glycosaminoglycan Binding and Non-Endocytic Membrane Translocation of Cell-Permeable Octaarginine Monitored by Real-Time In-Cell NMR Spectroscopy.
Glycosaminoglycan Binding and Non-Endocytic Membrane Translocation of Cell-Permeable Octaarginine Monitored by Real-Time In-Cell NMR Spectroscopy.
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Pharmaceuticals (Basel). 2017 Apr 15;10(2):
Authors: Takechi-Haraya Y, Aki K, Tohyama Y, Harano Y, Kawakami T, Saito H, Okamura E
Abstract
Glycosaminoglycans (GAGs), which are covalently-linked membrane proteins at the cell...
Transient Enzyme–Substrate Recognition Monitored by Real-Time NMR
Transient Enzyme–Substrate Recognition Monitored by Real-Time NMR
Caroline Haupt, Rica Patzschke, Ulrich Weininger, Stefan Gro?ger, Michael Kovermann and Jochen Balbach
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja2010048/aop/images/medium/ja-2011-010048_0002.gif
Journal of the American Chemical Society
DOI: 10.1021/ja2010048
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA
http://feeds.feedburner.com/~r/acs/jacsat/~4/nknzYbs0FNE
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06-30-2011 05:01 AM
Transient enzyme-substrate recognition monitored by real-time NMR.
Transient enzyme-substrate recognition monitored by real-time NMR.
Transient enzyme-substrate recognition monitored by real-time NMR.
J Am Chem Soc. 2011 Jun 10;
Authors: Haupt C, Patzschke R, Weininger U, Gröger S, Kovermann M, Balbach J
Slow protein folding processes during which kinetic folding intermediates occur for an extended time can lead to aggregation and dysfunction in living cells. Therefore protein folding helpers have evolved, which prevent proteins from aggregation and/ or speed up folding processes. In this study we present the...
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Kinetic analysis of protein aggregation monitored by real-time 2D solid-state NMR spectroscopy
Kinetic analysis of protein aggregation monitored by real-time 2D solid-state NMR spectroscopy
Abstract It is shown that real-time 2D solid-state NMR can be used to obtain kinetic and structural information about the process of protein aggregation. In addition to the incorporation of kinetic information involving intermediate states, this approach can offer atom-specific resolution for all detectable species. The analysis was carried out using experimental data obtained during aggregation of the 10.4 kDa Crh protein, which has been shown to involve a partially unfolded intermediate...
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01-27-2011 04:31 AM
Kinetic analysis of protein aggregation monitored by real-time 2D solid-state NMR spectroscopy.
Kinetic analysis of protein aggregation monitored by real-time 2D solid-state NMR spectroscopy.
Kinetic analysis of protein aggregation monitored by real-time 2D solid-state NMR spectroscopy.
J Biomol NMR. 2011 Jan 21;
Authors: Etzkorn M, Böckmann A, Baldus M
It is shown that real-time 2D solid-state NMR can be used to obtain kinetic and structural information about the process of protein aggregation. In addition to the incorporation of kinetic information involving intermediate states, this approach can offer atom-specific resolution for all...
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01-22-2011 01:52 PM
[NMR paper] Folding of a beta-sheet protein monitored by real-time NMR spectroscopy.
Folding of a beta-sheet protein monitored by real-time NMR spectroscopy.
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J Mol Biol. 2003 May 16;328(5):1161-71
Authors: Mizuguchi M, Kroon GJ, Wright PE, Dyson HJ
At low ionic strength, apoplastocyanin forms an unfolded state under non-denaturing conditions. The refolding of this state is sufficiently slow to allow real-time NMR experiments to be performed. Folding of apoplastocyanin, initiated by the addition of salt and followed by real-time 2D 1H-15N...
Salt-mediated oligomerization of the mouse prion protein monitored by real time NMR
Linear Mode
