Hi! I'm just hoping someone can give me a basic overview of how electron paramagnetic resonance works. I have a basic understanding of how NMR works, but wasn't really able to find a solid, easy to understand overview of EPR. The wikipedia page seemed to give an ok explanation, but I want to confirm I've understood it correctly. Thanks in advance to anyone who can help :)
Metalloenzyme catalysis : Through the use of cryoreduction and annealing, a method of studying electron transfer in redox active metalloenzymes is developed. Combined with electron paramagnetic resonance spectroscopy, active states in the catalytic cycle of the copper containing nitrite reductases are probed.
Abstract
Redox active metalloenzymes catalyse a range of biochemical processes essential for life. However, due to their complex reaction mechanisms, and often, their poor optical signals, detailed mechanistic understandings of them are limited. Here, we develop a cryoreduction approach coupled to electron paramagnetic resonance measurements to study electron transfer between the copper centers in the copper nitrite reductase (CuNiR) family of enzymes. Unlike alternative methods used to study electron transfer reactions, the cryoreduction approach presented here allows observation of the redox state of both metal centers, a direct read‐out of electron transfer, determines the presence of the substrate/product in the active site and shows the importance of protein motion in inter‐copper electron transfer catalyzed by CuNiRs. Cryoreduction‐EPR is broadly applicable for the study of electron transfer in other redox enzymes and paves the way to explore transient states in multiple redox‐center containing proteins (homo and hetero metal ions).
https://ift.tt/35n340D
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c01754
https://ift.tt/2MFDFqr
This one is tricky as I can't find it on Pubmed or anything.
Title: Studies of cyanide binding to myeloperoxidase by electron paramagnetic resonance and magnetic circular dichroism spectroscopies.
Authors: Eglinton, D.G.; Barber, D.; Thomson, A.J.; Greenwood, C.; Segal, A.W.
Citation: Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular Enzymology vol. 703 issue 2 May 3, 1982. p. 187-195
A few links:
I've requested a copy on Researchgate but I have no idea how long that takes to go through. Could be days, weeks, months... Any help from you folks?
Really confused on this and I am having a lot of trouble finding any articles with explanations on this. Was wondering if any chemists knew the answer.
https://preview.redd.it/ysl6z2xqztr71.png?width=509&format=png&auto=webp&s=aafbe0ecc47fe8589143175ed66e3b956a08c569
https://preview.redd.it/17qlzfouztr71.png?width=229&format=png&auto=webp&s=418981649f09a1c936c9188020b6d4d6682fe672
https://preview.redd.it/ap62z97xztr71.png?width=135&format=png&auto=webp&s=c257ba8e613198bf88457242cfa9943c6078e757
Mechanistic insights into protein–ligand interactions can yield chemical tools for modulating protein function and enable their use for therapeutic purposes. For the homodimeric enzyme tRNA-guanine transglycosylase (TGT), a putative virulence target of shigellosis, ligand binding has been shown by crystallography to transform the functional dimer geometry into an incompetent twisted one. However, crystallographic observation of both end states does neither verify the ligand-induced transformation of one dimer into the other in solution nor does it shed light on the underlying transformation mechanism. We addressed these questions in an approach that combines site-directed spin labeling (SDSL) with distance measurements based on pulsed electron–electron double resonance (PELDOR or DEER) spectroscopy. We observed an equilibrium between the functional and twisted dimer that depends on the type of ligand, with a pyranose-substituted ligand being the most potent one in shifting the equilibrium toward the twisted dimer. Our experiments suggest a dissociation–association mechanism for the formation of the twisted dimer upon ligand binding.
https://ift.tt/3jQnZ3C
Journal of the American Chemical SocietyDOI: 10.1021/jacs.1c01359
Fabian Hecker, JoAnne Stubbe, and Marina Bennati
https://ift.tt/3tr9yGb
Redox active metalloenzymes catalyse a range of biochemical processes essential for life. However, due to their complex reaction mechanisms, and often, their poor optical signals, detailed mechanistic understandings of them are limited. Here, we develop a cryoreduction approach coupled to electron paramagnetic resonance measurements to study electron transfer between the copper centers in the copper nitrite reductase (CuNiR) family of enzymes. Unlike alternative methods used to study electron transfer reactions, the cryoreduction approach presented here allows observation of the redox state of both metal centers, a direct read‐out of electron transfer, determines the presence of the substrate/product in the active site and shows the importance of protein motion in inter‐copper electron transfer catalyzed by CuNiRs. Cryoreduction‐EPR is broadly applicable for the study of electron transfer in other redox enzymes and paves the way to explore transient states in multiple redox‐centre containing proteins (homo and hetero metal ions).
https://ift.tt/35n340D
