共查询到20条相似文献，搜索用时 15 毫秒
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(4):1022-1026
A protein can be in different conformations when fulfilling its function. Yet depiction of protein structural ensembles remains difficult. Here we show that the accurate measurement of solvent paramagnetic relaxation enhancement (sPRE) in the presence of an inert paramagnetic cosolute allows the assessment of protein dynamics. Demonstrated with two multi‐domain proteins, we present a method to characterize protein microsecond–millisecond dynamics based on the analysis of the sPRE. Provided with the known structures of a protein, our method uncovers an ensemble of structures that fully accounts for the observed sPRE. In conjunction with molecular dynamics simulations, our method can identify protein alternative conformation that has only been theorized before. Together, our method expands the application of sPRE beyond structural characterization of rigid proteins and complements the established PRE NMR technique. 相似文献
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Frans A. A. Mulder Leonardo Tenori Claudio Luchinat 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(43):15427-15430
NMR spectroscopy is an indispensable technique for the determination of the chemical identity and structure of small molecules. The method is especially recognized for its robustness and intrinsically quantitative nature, and has manifested itself as a key analytical platform for diverse fields of application, ranging from chemical synthesis to metabolomics. Unfortunately, the slow recovery of nuclear spin polarization by spin‐lattice (T1) relaxation causes most experimental time to be lost on idle waiting. Furthermore, truly quantitative NMR (qNMR) spectroscopy requires waiting times of 5‐times the longest T1 in the sample, making qNMR spectroscopy slow and inefficient. We demonstrate here that co‐solute paramagnetic relaxation can mitigate these two problems simultaneously. The addition of a small amount of paramagnetic gadolinium chelate, available in the form of commercial contrast‐agent solutions, enables cheap, quantitative, and efficient high‐throughput mixture analysis. 相似文献
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Nathaniel Z. Hardin Voj
Kocman Giacomo M. Di Mauro Thirupathi Ravula Ayyalusamy Ramamoorthy 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17406-17410
Paramagnetic relaxation enhancement (PRE) is commonly used to speed up spin lattice relaxation time (T1) for rapid data acquisition in NMR structural studies. Consequently, there is significant interest in novel paramagnetic labels for enhanced NMR studies on biomolecules. Herein, we report the synthesis and characterization of a modified poly(styrene‐co‐maleic acid) polymer which forms nanodiscs while showing the ability to chelate metal ions. Cu2+‐chelated nanodiscs are demonstrated to reduce the T1 of protons for both polymer and lipid‐nanodisc components. The chelated nanodiscs also decrease the proton T1 values for a water‐soluble DNA G‐quadruplex. These results suggest that polymer nanodiscs functionalized with paramagnetic tags can be used to speed‐up data acquisition from lipid bilayer samples and also to provide structural information from water‐soluble biomolecules. 相似文献
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Hamed Kooshapur Junhe Ma Nico Tjandra Guillermo A. Bermejo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(47):17055-17058
Glutamine‐binding protein (GlnBP) displays an apo, “open” and a holo, “closed” crystal form, mutually related by a rigid‐body reorientation of its domains. A fundamental question about such large‐scale conformational transitions, whether the closed state exists in the absence of ligand, is controversial in the case of GlnBP. NMR observations have indicated no evidence of the closed form, whereas experimentally validated computations have suggested a remarkable ca. 40 % population. Herein, a paramagnetic NMR strategy designed to detect the putative apo‐closed species shows that a major population of the latter is highly improbable. Further, NMR residual dipolar couplings collected under three anisotropic conditions do not reveal differential domain alignment and establish that the average solution conformation is satisfied by the apo‐open crystal structure. Our results indicate that the computational prediction of large‐scale interdomain motions is not trivial and may lead to erroneous conclusions without proper experimental validation. 相似文献
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