Sensitivity of V2' saturation transfer electron paramagnetic resonance signals to anisotropic rotational diffusion with [15N]nitroxide spin-labels. Effects of noncoincident magnetic and diffusion tensor principal axes

1983 ◽  
Vol 87 (2) ◽  
pp. 359-367 ◽  
Author(s):  
K. Balasubramanian ◽  
A. H. Beth ◽  
B. H. Robinson ◽  
L. R. Dalton ◽  
S. D. Venkataramu ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Rotational Diffusion ◽  
Spin Labels ◽  
Saturation Transfer ◽  
Paramagnetic Resonance ◽  
Principal Axes ◽  
Nitroxide Spin Labels ◽  
Electron Paramagnetic ◽  
Anisotropic Rotational Diffusion ◽  
And Diffusion

scholarly journals DNA complexes with human apurinic/apyrimidinic endonuclease 1: structural insights revealed by pulsed dipolar EPR with orthogonal spin labeling

2019 ◽  
Vol 47 (15) ◽  
pp. 7767-7780 ◽  
Author(s):  
Olesya A Krumkacheva ◽  
Georgiy Yu Shevelev ◽  
Alexander A Lomzov ◽  
Nadezhda S Dyrkheeva ◽  
Andrey A Kuzhelev ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Md Simulations ◽  
Dna Lesions ◽  
Spin Labels ◽  
Paramagnetic Resonance ◽  
Applied Pulse ◽  
Oligonucleotide Duplex ◽  
Nitroxide Spin Labels ◽  
Ap Sites ◽  
Electron Paramagnetic

Abstract A DNA molecule is under continuous influence of endogenous and exogenous damaging factors, which produce a variety of DNA lesions. Apurinic/apyrimidinic sites (abasic or AP sites) are among the most common DNA lesions. In this work, we applied pulse dipolar electron paramagnetic resonance (EPR) spectroscopy in combination with molecular dynamics (MD) simulations to investigate in-depth conformational changes in DNA containing an AP site and in a complex of this DNA with AP endonuclease 1 (APE1). For this purpose, triarylmethyl (TAM)-based spin labels were attached to the 5′ ends of an oligonucleotide duplex, and nitroxide spin labels were introduced into APE1. In this way, we created a system that enabled monitoring the conformational changes of the main APE1 substrate by EPR. In addition, we were able to trace substrate-to-product transformation in this system. The use of different (orthogonal) spin labels in the enzyme and in the DNA substrate has a crucial advantage allowing for detailed investigation of local damage and conformational changes in AP-DNA alone and in its complex with APE1.

Rotational Motions of Muscle Proteins Studied by Saturation-Transfer Electron Paramagnetic Resonance

1980 ◽  
Vol 34 (3) ◽  
pp. 280-288 ◽  
Author(s):  
John C. Seidel
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Spin Labels ◽  
Myofibrillar Proteins ◽  
Muscle Proteins ◽  
Saturation Transfer ◽  
Paramagnetic Resonance ◽  
Intact Muscle ◽  
Specific Muscle ◽  
Rotational Motions ◽  
Electron Paramagnetic

The sensitivity of saturation-transfer electron paramagnetic resonance to rotational motion in the submillisecond range provides a means of studying rotational motions of the myofibrillar proteins of muscle and segments of these proteins. Estimates of these rotational motions have been made using purified proteins and supramolecular complexes that have been formed by assembly of purified proteins or isolated as such by partially disrupting the intact muscle cell. These motions are of particular relevance to an understanding of the molecular basis of energy transduction in muscle, where the force-generating step is generally believed to involve rotation of the myosin crossbridge about some point on the actin filament. By selectively introducing rigidly bound spin labels into specific muscle proteins and into specific regions of these proteins it has been possible to obtain insights into the molecular motions of myosin and actin, and into the nature of interaction between these proteins.

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