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Murzakhanov F, Mamin GV, Orlinskii S, Goldberg M, Petrakova NV, Fedotov AY, Grishin P, Gafurov MR, Komlev VS. Study of Electron-Nuclear Interactions in Doped Calcium Phosphates by Various Pulsed EPR Spectroscopy Techniques. ACS OMEGA 2021; 6:25338-25349. [PMID: 34632192 PMCID: PMC8495714 DOI: 10.1021/acsomega.1c03238] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/14/2021] [Indexed: 05/08/2023]
Abstract
Substituted calcium phosphates (CaPs) are vital materials for the treatment of bone diseases and repairing and replacement of defects in human hard tissues. In this paper, we present some applications of the rarely used pulsed electron paramagnetic resonance (EPR) and hyperfine interaction spectroscopy approaches [namely, electron spin-echo envelope modulation (ESEEM) and electron-electron double-resonance detected nuclear magnetic resonance (EDNMR)] to investigate synthetic CaPs (hydroxyapatite, tricalcium, and octacalcium phosphate) doped with various cations (Li+, Na+, Mn2+, Cu2+, Fe3+, and Ba2+). These resonance techniques provide reliable tools to obtain unique information about the presence and localization of impurity centers and values of hyperfine and quadrupole tensors. We show that revealed in CaPs by EPR techniques, radiation-induced stable nitrogen-containing species and carbonate radicals can serve as sensitive paramagnetic probes to follow CaPs' structural changes caused by cation doping. The most pulsed EPR, ESEEM, and EDNMR spectra can be detected at room temperature, reducing the costs of the measurements and facilitating the usage of pulsed EPR techniques for CaP characterization.
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Affiliation(s)
- Fadis Murzakhanov
- Kazan
Federal University, 18
Kremlevskaya Str., Kazan 420008, Russian Federation
| | | | - Sergei Orlinskii
- Kazan
Federal University, 18
Kremlevskaya Str., Kazan 420008, Russian Federation
| | - Margarita Goldberg
- A.A.
Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Leninskiy Prospect 49, Moscow 119334, Russian Federation
| | - Nataliya V. Petrakova
- A.A.
Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Leninskiy Prospect 49, Moscow 119334, Russian Federation
| | - Alexander Y. Fedotov
- A.A.
Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Leninskiy Prospect 49, Moscow 119334, Russian Federation
| | - Peter Grishin
- Kazan
State Medical University, 49 Butlerova Str., Kazan 420012, Russian Federation
| | - Marat R. Gafurov
- Kazan
Federal University, 18
Kremlevskaya Str., Kazan 420008, Russian Federation
| | - Vladimir S. Komlev
- A.A.
Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Leninskiy Prospect 49, Moscow 119334, Russian Federation
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2
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Sahu ID, Lorigan GA. Electron Paramagnetic Resonance as a Tool for Studying Membrane Proteins. Biomolecules 2020; 10:E763. [PMID: 32414134 PMCID: PMC7278021 DOI: 10.3390/biom10050763] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/24/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022] Open
Abstract
Membrane proteins possess a variety of functions essential to the survival of organisms. However, due to their inherent hydrophobic nature, it is extremely difficult to probe the structure and dynamic properties of membrane proteins using traditional biophysical techniques, particularly in their native environments. Electron paramagnetic resonance (EPR) spectroscopy in combination with site-directed spin labeling (SDSL) is a very powerful and rapidly growing biophysical technique to study pertinent structural and dynamic properties of membrane proteins with no size restrictions. In this review, we will briefly discuss the most commonly used EPR techniques and their recent applications for answering structure and conformational dynamics related questions of important membrane protein systems.
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Affiliation(s)
- Indra D. Sahu
- Natural Science Division, Campbellsville University, Campbellsville, KY 42718, USA
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Gary A. Lorigan
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
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3
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Yee EF, Dzikovski B, Crane BR. Tuning Radical Relay Residues by Proton Management Rescues Protein Electron Hopping. J Am Chem Soc 2019; 141:17571-17587. [PMID: 31603693 DOI: 10.1021/jacs.9b05715] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Transient tyrosine and tryptophan radicals play key roles in the electron transfer (ET) reactions of photosystem (PS) II, ribonucleotide reductase (RNR), photolyase, and many other proteins. However, Tyr and Trp are not functionally interchangeable, and the factors controlling their reactivity are often unclear. Cytochrome c peroxidase (CcP) employs a Trp191•+ radical to oxidize reduced cytochrome c (Cc). Although a Tyr191 replacement also forms a stable radical, it does not support rapid ET from Cc. Here we probe the redox properties of CcP Y191 by non-natural amino acid substitution, altering the ET driving force and manipulating the protic environment of Y191. Higher potential fluorotyrosine residues increase ET rates marginally, but only addition of a hydrogen bond donor to Tyr191• (via Leu232His or Glu) substantially alters activity by increasing the ET rate by nearly 30-fold. ESR and ESEEM spectroscopies, crystallography, and pH-dependent ET kinetics provide strong evidence for hydrogen bond formation to Y191• by His232/Glu232. Rate measurements and rapid freeze quench ESR spectroscopy further reveal differences in radical propagation and Cc oxidation that support an increased Y191• formal potential of ∼200 mV in the presence of E232. Hence, Y191 inactivity results from a potential drop owing to Y191•+ deprotonation. Incorporation of a well-positioned base to accept and donate back a hydrogen bond upshifts the Tyr• potential into a range where it can effectively oxidize Cc. These findings have implications for the YZ/YD radicals of PS II, hole-hopping in RNR and cryptochrome, and engineering proteins for long-range ET reactions.
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Affiliation(s)
- Estella F Yee
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
| | - Boris Dzikovski
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States.,National Biomedical Center for Advanced ESR Technologies (ACERT) , Cornell University , Ithaca , New York 14850 , United States
| | - Brian R Crane
- Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States
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Liu L, Sahu ID, Bottorf L, McCarrick RM, Lorigan GA. Investigating the Secondary Structure of Membrane Peptides Utilizing Multiple 2H-Labeled Hydrophobic Amino Acids via Electron Spin Echo Envelope Modulation (ESEEM) Spectroscopy. J Phys Chem B 2018; 122:4388-4396. [PMID: 29614227 DOI: 10.1021/acs.jpcb.7b11890] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An electron spin echo envelope modulation (ESEEM) approach was used to probe local secondary structures of membrane proteins and peptides. This ESEEM method detects dipolar couplings between 2H-labeled nuclei on the side chains of an amino acid (Leu or Val) and a strategically placed nitroxide spin-label in the proximity up to 8 Å. ESEEM spectra patterns for different samples correlate directly to the periodic structural feature of different secondary structures. Since this pattern can be affected by the side chain length and flexibility of the 2H-labeled amino acid used in the experiment, it is important to examine several different hydrophobic amino acids (d3 Ala, d8 Val, d8 Phe) utilizing this ESEEM approach. In this work, a series of ESEEM data were collected on the AChR M2δ membrane peptide to build a reference for the future application of this approach for various biological systems. The results indicate that, despite the relative intensity and signal-to-noise level, all amino acids share a similar ESEEM modulation pattern for α-helical structures. Thus, all commercially available 2H-labeled hydrophobic amino acids can be utilized as probes for the further application of this ESEEM approach. Also, the ESEEM signal intensities increase as the side chain length gets longer or less rigid. In addition, longer side chain amino acids had a larger 2H ESEEM FT peak centered at the 2H Larmor frequency for the i ± 4 sample when compared to the corresponding i ± 3 sample. For shorter side chain amino acids, the 2H ESEEM FT peak intensity ratio between i ± 4 and i ± 3 was not well-defined.
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Affiliation(s)
- Lishan Liu
- Department of Chemistry and Biochemistry , Miami University , Oxford , Ohio 45056 , United States
| | - Indra D Sahu
- Department of Chemistry and Biochemistry , Miami University , Oxford , Ohio 45056 , United States
| | - Lauren Bottorf
- Department of Chemistry and Biochemistry , Miami University , Oxford , Ohio 45056 , United States
| | - Robert M McCarrick
- Department of Chemistry and Biochemistry , Miami University , Oxford , Ohio 45056 , United States
| | - Gary A Lorigan
- Department of Chemistry and Biochemistry , Miami University , Oxford , Ohio 45056 , United States
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Audran G, Bosco L, Brémond P, Butscher T, Franconi JM, Marque SRA, Mellet P, Parzy E, Santelli M, Thiaudière E. The β-phosphorus hyperfine coupling constant in nitroxide: part 3: titration of water by electron paramagnetic resonance. Org Biomol Chem 2015; 13:11393-400. [PMID: 26395177 DOI: 10.1039/c5ob01867f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recently, we showed that the phosphorus hyperfine coupling constant aPβ of persistent cyclic nitroxides decreased with the normalized polarity Reichardt's constant E. Thus, we investigated the changes in aPβ in binary mixtures of solvents. The sensitivity of aPβ to the solvent was high enough to allow us to perform water titration in THF, 1,4-dioxane, and acetonitrile by EPR. Accuracies of a few percent were achieved.
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Affiliation(s)
- Gérard Audran
- Aix-Marseille Université, CNRS-UMR 7273, ICR, case 541, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
| | - Lionel Bosco
- Aix-Marseille Université, CNRS-UMR 7273, ICR, case 541, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
| | - Paul Brémond
- Aix-Marseille Université, CNRS-UMR 7273, ICR, case 541, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
| | - Teddy Butscher
- Aix-Marseille Université, CNRS-UMR 7273, ICR, case 541, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
| | - Jean-Michel Franconi
- CRMSB, CNRS-UMR-5536, Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, Case 93, 33076 Bordeaux Cedex, France
| | - Sylvain R A Marque
- Aix-Marseille Université, CNRS-UMR 7273, ICR, case 541, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France. and N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090 Novosibirsk, Russia
| | - Philippe Mellet
- CRMSB, CNRS-UMR-5536, Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, Case 93, 33076 Bordeaux Cedex, France and INSERM, 146 rue Léo Saignat, Case 93, 33076 Bordeaux Cedex, France
| | - Elodie Parzy
- CRMSB, CNRS-UMR-5536, Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, Case 93, 33076 Bordeaux Cedex, France
| | - Maurice Santelli
- Aix-Marseille Université, CNRS-UMR 7273, ICR, case 541, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
| | - Eric Thiaudière
- CRMSB, CNRS-UMR-5536, Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, Case 93, 33076 Bordeaux Cedex, France
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Bortolus M, Dalzini A, Toniolo C, Hahm KS, Maniero AL. Interaction of hydrophobic and amphipathic antimicrobial peptides with lipid bicelles. J Pept Sci 2014; 20:517-25. [PMID: 24863176 DOI: 10.1002/psc.2645] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/10/2014] [Indexed: 02/03/2023]
Abstract
Bicelles are model membrane systems that can be macroscopically oriented in a magnetic field at physiological temperature. The macroscopic orientation of bicelles allows to detect, by means of magnetic resonance spectroscopies, small changes in the order of the bilayer caused by solutes interacting with the membrane. These changes would be hardly detectable in isotropic systems such as vesicles or micelles. The aim of this work is to show that bicelles represent a convenient tool to investigate the behavior of antimicrobial peptides (AMPs) interacting with membranes, using electron paramagnetic resonance (EPR) spectroscopy. We performed the EPR experiments on spin-labeled bicelles using various AMPs of different length, charge, and amphipathicity: alamethicin, trichogin GA IV, magainin 2, HP(2-20), and HPA3. We evaluated the changes in the order parameter of the spin-labeled lipids as a function of the peptide-to-lipid ratio. We show that bicelles labeled at position 5 of the lipid chains are very sensitive to the perturbation induced by the AMPs even at low peptide concentrations. Our study indicates that peptides that are known to disrupt the membrane by different mechanisms (i.e., alamethicin vs magainin 2) show very distinct trends of the order parameter as a function of peptide concentration. Therefore, spin-labeled bicelles proved to be a good system to evaluate the membrane disruption mechanism of new AMPs.
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Affiliation(s)
- Marco Bortolus
- Department of Chemistry, University of Padova, via Marzolo 1, Padova, 35131, Italy
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