Localization of metal ions in biomolecules by means of pulsed dipolar EPR spectroscopy

2021 ◽  
Author(s):  
Dinar Abdullin ◽  
Olav Schiemann
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Metal Ions ◽  
Epr Spectroscopy ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Spin Labeling ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Paramagnetic Metal ◽  
Site Directed Spin Labeling ◽  
Electron Paramagnetic

A method is introduced in which paramagnetic metal ions are localized by means of trilateration using a combination of site-directed spin labeling and pulsed dipolar electron paramagnetic resonance spectroscopy.

scholarly journals Site Selective and Efficient Spin Labeling of Proteins with a Maleimide-Functionalized Trityl Radical for Pulsed Dipolar EPR Spectroscopy

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2735 ◽  
Author(s):  
J. Jacques Jassoy ◽  
Caspar A. Heubach ◽  
Tobias Hett ◽  
Frédéric Bernhard ◽  
Florian R. Haege ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Spin Labeling ◽  
Single Frequency ◽  
Spin Labels ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
Site Directed Spin Labeling ◽  
Site Selective ◽  
Electron Paramagnetic

Pulsed dipolar electron paramagnetic resonance spectroscopy (PDS) in combination with site-directed spin labeling (SDSL) of proteins and oligonucleotides is a powerful tool in structural biology. Instead of using the commonly employed gem-dimethyl-nitroxide labels, triarylmethyl (trityl) spin labels enable such studies at room temperature, within the cells and with single-frequency electron paramagnetic resonance (EPR) experiments. However, it has been repeatedly reported that labeling of proteins with trityl radicals led to low labeling efficiencies, unspecific labeling and label aggregation. Therefore, this work introduces the synthesis and characterization of a maleimide-functionalized trityl spin label and its corresponding labeling protocol for cysteine residues in proteins. The label is highly cysteine-selective, provides high labeling efficiencies and outperforms the previously employed methanethiosulfonate-functionalized trityl label. Finally, the new label is successfully tested in PDS measurements on a set of doubly labeled Yersinia outer protein O (YopO) mutants.

Fibrils with parallel in-register structure constitute a major class of amyloid fibrils: molecular insights from electron paramagnetic resonance spectroscopy

2008 ◽  
Vol 41 (3-4) ◽  
pp. 265-297 ◽  
Author(s):  
Martin Margittai ◽  
Ralf Langen
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Amyloid Fibrils ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Spin Labeling ◽  
Spongiform Encephalopathy ◽  
Resonance Spectroscopy ◽  
Biological Functions ◽  
Paramagnetic Resonance ◽  
Site Directed Spin Labeling ◽  
Electron Paramagnetic

AbstractThe deposition of amyloid- and amyloid-like fibrils is the main pathological hallmark of numerous protein misfolding diseases including Alzheimer's disease, transmissible spongiform encephalopathy, and type 2 diabetes. Besides the well-established role in disease, recent work on a variety of organisms ranging from bacteria to humans suggests that amyloid fibrils can also convey biological functions. To better understand the molecular mechanisms by which amyloidogenic proteins misfold in disease or perform biological functions, structural information is essential. Although high-resolution structural analysis of amyloid fibrils has been challenging, a combination of biophysical approaches is beginning to unravel the various structural features of amyloid fibrils. Here we review these recent developments with particular emphasis on amyloid fibrils that have been studied using site-directed spin labeling and electron paramagnetic resonance spectroscopy. This approach has been used to define the precise location of fibril-forming core regions and identify local secondary structures within such core regions. Perhaps one of the most remarkable findings arrived at by site-directed spin labeling was that most fibrils that contain an extensive core region of ∼20 amino acids or more share a common parallel in-register arrangement of β strands. The preference for this arrangement can be explained on topological grounds and may be rationalized by the maximization of hydrophobic contact surface.

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