Publication year: 2011 Source: Journal of Magnetic Resonance, Available online 30 December 2011
Claudio*Luchinat, Malini*Nagulapalli, Giacomo*Parigi, Luca*Sgheri
Multidomain proteins are composed of rigid domains connected by (flexible) linkers. Therefore, the domains may experience a large degree of reciprocal reorientation. Pseudocontact shifts and residual dipolar couplings arising from one or more paramagnetic metals successively placed in a single metal binding site in the protein can be used as restraints to assess the degree of mobility of the different domains. They can be used to determine the maximum occurrence (MO) of each possible protein conformation, i.e. the maximum weight that such conformations can have independently of the real structural ensemble, in agreement with the provided restraints. In the case of two-domain proteins, the metal ions can be placed all in the same domain, or distributed between the two domains. It has been demonstrated that the quantity of independent information for the characterization of the system is larger when all metals are bound in the same domain. At the same time, it has been shown that there are practical advantages in placing the metals in different domains. Here, it is shown that distributing the metals between the domains provides a tool for defining a coefficient of compatibility among the restraints obtained from different metals, without a significant decrease of the capability of the MO values to discriminate among conformations with different weights. Graphical abstract
Highlights
? Paramagnetic metals within a protein provide pcs and paramagnetic rdc. ? Two-domain proteins with a flexible linker can sample multiple conformations. ? Pcs and paramagnetic rdc provide the maximum occurrence of each conformation. ? A compatibility index is defined if paramagnetic metals are bound in both domains.
Narrowing the conformational space sampled by two-domain proteins with paramagnetic probes in both domains
Narrowing the conformational space sampled by two-domain proteins with paramagnetic probes in both domains
Abstract Calmodulin is a two-domain protein which in solution can adopt a variety of conformations upon reorientation of its domains. The maximum occurrence (MO) of a set of calmodulin conformations that are representative of the overall conformational space possibly sampled by the protein, has been calculated from the paramagnetism-based restraints. These restraints were measured after inclusion of a lanthanide binding tag in the C-terminal domain to supplement the data obtained...
NMR studies of alkali metal ions in organic and biological solids
NMR studies of alkali metal ions in organic and biological solids
Publication year: 2011
Source: Progress in Nuclear Magnetic Resonance Spectroscopy, In Press, Accepted Manuscript, Available online 13 June 2011</br>
Gang, Wu , Jianfeng, Zhu</br>
*Highlights:*? Comprehensive review of NMR of alkali metal ions in organic/biological solids ? Experimental solid-state NMR techniques and computational methods ? Survey of experimental alkali metal NMR data for organic/biological solids</br></br>
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[NMR paper] Metal binding sites in proteins: identification and characterization by paramagnetic NMR relaxation.
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Authors: Jensen MR, Petersen G, Lauritzen C, Pedersen J, Led JJ
A method is presented that allows the identification and quantitative characterization of metal binding sites in proteins using paramagnetic nuclear magnetic resonance spectroscopy. The method relies on the nonselective...
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12-01-2010 06:56 PM
[NMR paper] Docking multiple conformations of a flexible ligand into a protein binding site using
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Authors: Zabell AP, Post CB
A method is described for docking a large, flexible ligand using intra-ligand conformational restraints from exchange-transferred NOE (etNOE) data. Numerous conformations of the ligand are generated in isolation, and a subset of representative conformations is...
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[NMR paper] NMR spectroscopic studies of I = 1/2 metal ions in biological systems.
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Authors: Oz G, Pountney DL, Armitage IM
This article reviews the use of nuclear magnetic resonance methods of spin 1/2 metal nuclei to probe the metal binding site(s) in a variety of metalloproteins. The majority of the studies have involved native Zn(II) and Ca(II) metalloproteins where there has been isostructural substitution of these metal ions...
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[NMR paper] Side-chain conformations in an unfolded protein: chi1 distributions in denatured hen
Side-chain conformations in an unfolded protein: chi1 distributions in denatured hen lysozyme determined by heteronuclear 13C, 15N NMR spectroscopy.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles Side-chain conformations in an unfolded protein: chi1 distributions in denatured hen lysozyme determined by heteronuclear 13C, 15N NMR spectroscopy.
J Mol Biol. 1999 May 14;288(4):705-23
Authors: Hennig M, Bermel W, Spencer A, Dobson CM, Smith LJ, Schwalbe H
Using a 13C and...