[NMR paper] Increasing nitroxide lifetime in cells to enable in-cell protein structure and dynamics measurements by electron spin resonance spectroscopy
Author(s): Kevin Singewald, Matthew J. Lawless, Sunil Saxena
Abstract
There is increasing evidence that the stability, structure, dynamics, and function of many proteins differ in cells versus in vitro. The determination of protein structure and dynamics within the native cellular environment may lead to better understanding of protein behavior. Electron spin resonance (ESR) has emerged as a technique that can report on protein structure and dynamics within cells. Nitroxide based spin labels are capable of reporting on protein dynamics, structure, and backbone flexibility but are limited due to nitroxide reduction occurring in cells. In order to overcome this limitation, we used the oxidizing agent potassium ferricyanide (K3Fe(CN)6) as well as the cleavage resistant spin label 3-malemido-PROXYL (5-MSL). Furthermore, we hypothesized that injection concentration is an important parameter regarding nitroxide reduction kinetics. By increasing the injection concentration of doubly 5-MSL labeled protein into Xenopus laevis oocytes, we found an increased nitroxide lifetime. Our work demonstrates unprecedented incubation times of 3-h in-cell and 5-h in-cytosol for double electron–electron resonance (DEER) experiments using nitroxide spin labels. This allows for more meaningful measurements of larger protein systems which may require longer incubation times for equilibration in the cellular milieu. Even longer incubation times are possible by combining our approach with more shielded nitroxides and Q-band.
[NMR paper] A bioresistant nitroxide spin label for in-cell EPR spectroscopy: in vitro and in oocytes protein structural dynamics studies.
A bioresistant nitroxide spin label for in-cell EPR spectroscopy: in vitro and in oocytes protein structural dynamics studies.
Approaching proteins structural dynamics and protein-protein interactions in the cellular environment is a fundamental challenge. Due to its absolute sensitivity and to its selectivity to paramagnetic species, Site-Directed Spin Labeling (SDSL) combined with Electron Paramagnetic Resonance (EPR) has the potential to evolve into an efficient method to follow conformational changes in proteins directly inside cells. Until now, the use of nitroxyde-based spin labels...
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Singlet lifetime measurements in an all-proton chemically equivalent spin system by hyperpolarization and weak spin lock transfers
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Singlet lifetime measurements in an all-proton chemically equivalent spin system by hyperpolarization and weak spin lock transfers
Zhang, Y., et al., Singlet lifetime measurements in an all-proton chemically equivalent spin system by hyperpolarization and weak spin lock transfers. Phys. Chem. Chem. Phys., 2015. 17(37): p. 24370-24375.
http://dx.doi.org/10.1039/C5CP03716F
[NMR paper] Protein dynamics in living cells studied by in-cell NMR spectroscopy.
Protein dynamics in living cells studied by in-cell NMR spectroscopy.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles Protein dynamics in living cells studied by in-cell NMR spectroscopy.
FEBS Lett. 2013 Jan 11;
Authors: Li C, Liu M
Abstract
Most proteins function in cells where protein concentrations can reach 400g/l. However, most quantitative studies of protein properties are performed in idealized, dilute conditions. Recently developed in-cell NMR techniques...
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02-03-2013 10:22 AM
Protein dynamics in living cells studied by in-cell NMR spectroscopy
Protein dynamics in living cells studied by in-cell NMR spectroscopy
Available online 11 January 2013
Publication year: 2013
Source:FEBS Letters</br>
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Most proteins function in cells where protein concentrations can reach 400g/l. However, most quantitative studies of protein properties are performed in idealized, dilute conditions. Recently developed in-cell NMR techniques can provide protein structure and other biophysical properties inside living cells at atomic resolution. Here we review how protein dynamics, including global and internal motions have been...
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02-03-2013 10:13 AM
Structure, Dynamics, and Kinetics of Weak Protein-Protein Complexes from NMR Spin Relaxation Measurements of Titrated Solutions.
Structure, Dynamics, and Kinetics of Weak Protein-Protein Complexes from NMR Spin Relaxation Measurements of Titrated Solutions.
Structure, Dynamics, and Kinetics of Weak Protein-Protein Complexes from NMR Spin Relaxation Measurements of Titrated Solutions.
Angew Chem Int Ed Engl. 2011 Mar 18;
Authors: Salmon L, Ortega Roldan JL, Lescop E, Licinio A, van Nuland N, Jensen MR, Blackledge M
Increasing nitroxide lifetime in cells to enable in-cell protein structure and dynamics measurements by electron spin resonance spectroscopy
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