CW EPR and DEER Methods to Determine BCL-2 Family Protein Structure and Interactions: Application of Site-Directed Spin Labeling to BAK Apoptotic Pores

  • Tirtha Mandal
  • Eric J. Hustedt
  • Likai Song
  • Kyoung Joon OhEmail author
Part of the Methods in Molecular Biology book series (MIMB, volume 1877)


The continuous wave (CW) and pulse electron paramagnetic resonance (EPR) methods enable the measurement of distances between spin-labeled residues in biopolymers including proteins, providing structural information. Here we describe the CW EPR deconvolution/convolution method and the four-pulse double electron–electron resonance (DEER) approach for distance determination, which were applied to elucidate the organization of the BAK apoptotic pores formed in the lipid bilayers.

Key words

Apoptotic pore Bcl-2 BAK BAX Convolution CW EPR DEER Deconvolution Distance measurement Site-directed spin labeling (SDSL) Tikhonov regularization DeerAnalysis DEFit FitGUI 



We thank Dr. Candice Klug at the National Biomedical EPR Center, Milwaukee, Wisconsin for the technical support in Q-band experiments. We also thank Drs. Gunnar Jeschke and Christian Altenbach for helpful discussions and Mr. Carter Grieve for his proofreading the manuscript. This work was supported by NIH grant R01GM097508, EPR Center of the Rosalind Franklin University of Medicine and Science, and the RFUMS Start-up fund to. K.J.O.; NIH grant P01 GM080513 to E.J.H.; NIH grants RR022422 (DEER instrumentation grant), OD011937 (DEER instrumentation grant), and EB001980 (National Biomedical EPR Center grant) to C.K; and NSF Cooperative Agreement No. DMR-1644779 to L.S.


  1. 1.
    Hubbell WL, Altenbach C (1994) Site-directed spin labeling of membrane proteins. In: Membrane protein structure: experimental approaches. Oxford University Press, London, pp 244–248Google Scholar
  2. 2.
    Hubbell WL, Lopez CJ, Altenbach C, Yang Z (2013) Technological advances in site-directed spin labeling of proteins. Curr Opin Struct Biol 23:725–733. Scholar
  3. 3.
    Roser P, Schmidt MJ, Drescher M, Summerer D (2016) Site-directed spin labeling of proteins for distance measurements in vitro and in cells. Org Biomol Chem 14(24):5468–5476. Scholar
  4. 4.
    Fanucci GE, Cafiso DS (2006) Recent advances and applications of site-directed spin labeling. Curr Opin Struct Biol 16(5):644–653. Scholar
  5. 5.
    Altenbach C, Flitsch SL, Khorana HG, Hubbell WL (1989) Structural studies on transmembrane proteins. 2. Spin labeling of bacteriorhodopsin mutants at unique cysteines. Biochemistry 28(19):7806–7812CrossRefPubMedGoogle Scholar
  6. 6.
    Altenbach C, Greenhalgh DA, Khorana HG, Hubbell WL (1994) A collision gradient method to determine the immersion depth of nitroxides in lipid bilayers: application to spin-labeled mutants of bacteriorhodopsin. Proc Natl Acad Sci U S A 91(5):1667–1671CrossRefPubMedPubMedCentralGoogle Scholar
  7. 7.
    Fleissner MR, Bridges MD, Brooks EK, Cascio D, Kalai T, Hideg K, Hubbell WL (2011) Structure and dynamics of a conformationally constrained nitroxide side chain and applications in EPR spectroscopy. Proc Natl Acad Sci U S A 108(39):16241–16246. Scholar
  8. 8.
    Stevens MA, McKay JE, Robinson JLS, El Mkami H, Smith GM, Norman DG (2016) The use of the Rx spin label in orientation measurement on proteins, by EPR. Phys Chem Chem Phys 18(8):5799–5806. Scholar
  9. 9.
    Islam SM, Roux B (2015) Simulating the distance distribution between spin-labels attached to proteins. J Phys Chem B 119(10):3901–3911. Scholar
  10. 10.
    Sahu ID, McCarrick RM, Troxel KR, Zhang R, Smith HJ, Dunagan MM, Swartz MS, Rajan PV, Kroncke BM, Sanders CR, Lorigan GA (2013) DEER EPR measurements for membrane protein structures via bifunctional spin labels and lipodisq nanoparticles. Biochemistry 52(38):6627–6632. Scholar
  11. 11.
    Hustedt EJ, Smirnov AI, Laub CF, Cobb CE, Beth AH (1997) Molecular distances from dipolar coupled spin-labels: the global analysis of multifrequency continuous wave electron paramagnetic resonance data. Biophys J 72(4):1861–1877. Scholar
  12. 12.
    Rabenstein MD, Shin YK (1995) Determination of the distance between two spin labels attached to a macromolecule. Proc Natl Acad Sci U S A 92(18):8239–8243CrossRefPubMedPubMedCentralGoogle Scholar
  13. 13.
    Altenbach C, Oh KJ, Trabanino RJ, Hideg K, Hubbell WL (2001) Estimation of inter-residue distances in spin labeled proteins at physiological temperatures: experimental strategies and practical limitations. Biochemistry 40(51):15471–15482CrossRefPubMedGoogle Scholar
  14. 14.
    Pannier M, Veit S, Godt A, Jeschke G, Spiess HW (2000) Dead-time free measurement of dipole-dipole interactions between electron spins. J Magn Reson 142(2):331–340. Scholar
  15. 15.
    Oh KJ, Singh P, Lee K, Foss K, Lee S, Park M, Aluvila S, Kim RS, Symersky J, Walters DE (2010) Conformational changes in BAK, a pore-forming proapoptotic Bcl-2 family member, upon membrane insertion and direct evidence for the existence of BH3-BH3 contact interface in BAK homo-oligomers. J Biol Chem 285(37):28924–28937. Scholar
  16. 16.
    Aluvila S, Mandal T, Hustedt E, Fajer P, Choe JY, Oh KJ (2014) Organization of the mitochondrial apoptotic BAK pore: oligomerization of the BAK homodimers. J Biol Chem 289(5):2537–2551. Scholar
  17. 17.
    Mandal T, Shin S, Aluvila S, Chen HC, Grieve C, Choe JY, Cheng EH, Hustedt EJ, Oh KJ (2016) Assembly of Bak homodimers into higher order homooligomers in the mitochondrial apoptotic pore. Sci Rep 6:30763. Scholar
  18. 18.
    Oh KJ, Altenbach C, Collier RJ, Hubbell WL (2000) Site-directed spin labeling of proteins. Applications to diphtheria toxin. In: Holst O (ed) Bacterial toxins. Methods and protocols, Methods in molecular biology, vol 145. Humana Press, Totowa, NJ, pp 147–169CrossRefGoogle Scholar
  19. 19.
    Eaton SS, Eaton GR (2000) Distance measurements by CW and pulsed EPR. In: Berliner LJ, Eaton SS, Eaton GR (eds) Biological magnetic resonance, vol 19. Kluwer Academic/Plenum Publishers, New York, pp 1–27Google Scholar
  20. 20.
    Kittell AW, Hustedt EJ, Hyde JS (2012) Inter-spin distance determination using L-band (1–2 GHz) non-adiabatic rapid sweep electron paramagnetic resonance (NARS EPR). J Magn Reson 221:51–56. Scholar
  21. 21.
    Yang Z, Bridges MD, Lopez CJ, Rogozhnikova OY, Trukhin DV, Brooks EK, Tormyshev V, Halpern HJ, Hubbell WL (2016) A triarylmethyl spin label for long-range distance measurement at physiological temperatures using T1 relaxation enhancement. J Magn Reson 269:50–54. Scholar
  22. 22.
    Borbat PP, Georgieva ER, Freed JH (2013) Improved sensitivity for long-distance measurements in biomolecules: five-pulse double electron–electron resonance. J Phys Chem Lett 4(1):170–175. Scholar
  23. 23.
    Saxena S, Freed JH (1996) Double quantum two-dimensional Fourier transform electron spin resonance: distance measurements. Chem Phys Lett 251(1):102–110. Scholar
  24. 24.
    Miick SM, Martinez GV, Fiori WR, Todd AP, Millhauser GL (1992) Short alanine-based peptides may form 3(10)-helices and not alpha-helices in aqueous solution. Nature 359(6396):653–655. Scholar
  25. 25.
    Chen M, Margittai M, Chen J, Langen R (2007) Investigation of alpha-synuclein fibril structure by site-directed spin labeling. J Biol Chem 282(34):24970–24979. Scholar
  26. 26.
    Steinhoff HJ, Radzwill N, Thevis W, Lenz V, Brandenburg D, Antson A, Dodson G, Wollmer A (1997) Determination of interspin distances between spin labels attached to insulin: comparison of electron paramagnetic resonance data with the X-ray structure. Biophys J 73(6):3287–3298. Scholar
  27. 27.
    Hustedt EJ, Stein RA, Sethaphong L, Brandon S, Zhou Z, Desensi SC (2006) Dipolar coupling between nitroxide spin labels: the development and application of a tether-in-a-cone model. Biophys J 90(1):340–356. Scholar
  28. 28.
    Hustedt EJ, Beth AH (2000) Structural information from CW-EPR spectra of dipolar coupled nitroxide spin labels. In: Berliner LJ, Eaton SS, Eaton GR (eds) Biological magnetic resonance, vol 19. Kluwer Academic/Plenum Publishers, New York, pp 155–184Google Scholar
  29. 29.
    Zhou Z, DeSensi SC, Stein RA, Brandon S, Dixit M, McArdle EJ, Warren EM, Kroh HK, Song L, Cobb CE, Hustedt EJ, Beth AH (2005) Solution structure of the cytoplasmic domain of erythrocyte membrane band 3 determined by site-directed spin labeling. Biochemistry 44(46):15115–15128. Scholar
  30. 30.
    Pake GE (1948) Nuclear resonance absorption in hydrated crystals: fine structure of the proton line. J Chem Phys 16(4):327–336. Scholar
  31. 31.
    Jeschke G (2012) DEER distance measurements on proteins. Annu Rev Phys Chem 63:419–446. Scholar
  32. 32.
    Jeschke G (2002) Determination of the nanostructure of polymer materials by electron paramagnetic resonance spectroscopy. Macromol Rapid Commun 23(4):227–246.<227::AID-MARC227>3.0.CO;2-DCrossRefGoogle Scholar
  33. 33.
    McHaourab HS, Oh KJ, Fang CJ, Hubbell WL (1997) Conformation of T4 lysozyme in solution. Hinge-bending motion and the substrate-induced conformational transition studied by site-directed spin labeling. Biochemistry 36(2):307–316CrossRefGoogle Scholar
  34. 34.
    Slichter CP (1990) Principles of magnetic resonance. In: Springer series in solid-state sciences, vol 1, third enlarged and updated edition. Springer, New York, pp 65–70Google Scholar
  35. 35.
    Jeschke G, Pannier M, Spiess HW (2000) Double electron-electron resonance. In: Berliner LJ, Eaton SS, Eaton GR (eds) Biological magnetic resonance, vol 19. Kluwer Academic/Plenum Publishers, New York, pp 493–512Google Scholar
  36. 36.
    Jeschke G, Spiess HW (2006) Distance measurements in solid-state NMR and EPR spectroscopy. In: Lecture notes in physics, vol 684. Springer-Berlag, Berlin, Heidelberg, pp 21–63Google Scholar
  37. 37.
    Milov AD, Maryasov AG, Tsvetkov YD (1998) Pulsed electron double resonance (PELDOR) and its applications in free-radicals research. Appl Magn Reson 15:107–143CrossRefGoogle Scholar
  38. 38.
    Coffman RE, Buettner GR (1979) A limit function for long-range ferromagnetic and antiferromagnetic superexchange. J Phys Chem 83(18):2387–2392. Scholar
  39. 39.
    Jeschke G, Polyhach Y (2007) Distance measurements on spin-labelled biomacromolecules by pulsed electron paramagnetic resonance. Phys Chem Chem Phys 9(16):1895–1910. Scholar
  40. 40.
    Milov AD, Salikhov KM, Shirov MD (1981) Application of ELDOR in electron spin echo for magnetic center space distributions in solids. Fizika tverdogo tela 23(4):975–982Google Scholar
  41. 41.
    Fajer PG, Brown L, Song L (2007) Practical pulsed dipolar ESR (DEER). In: Hemminga MA, Berliner LJ (eds) ESR spectroscopy in membrane biophysics, Biological magnetic resonance, vol 27. Springer, New York, pp 95–128CrossRefGoogle Scholar
  42. 42.
    Jeschke G, Bender A, Paulsen H, Zimmermann H, Godt A (2004) Sensitivity enhancement in pulse EPR distance measurements. J Magn Reson 169(1):1–12. Scholar
  43. 43.
    Ward R, Bowman A, Sozudogru E, El-Mkami H, Owen-Hughes T, Norman DG (2010) EPR distance measurements in deuterated proteins. J Magn Reson 207(1):164–167. Scholar
  44. 44.
    Ghimire H, McCarrick RM, Budil DE, Lorigan GA (2009) Significantly improved sensitivity of Q-band PELDOR/DEER experiments relative to X-band is observed in measuring the intercoil distance of a leucine zipper motif peptide (GCN4-LZ). Biochemistry 48(25):5782–5784. Scholar
  45. 45.
    Zou P, McHaourab HS (2010) Increased sensitivity and extended range of distance measurements in spin-labeled membrane proteins: Q-band double electron-electron resonance and nanoscale bilayers. Biophys J 98(6):L18–L20. Scholar
  46. 46.
    Swanson MA, Kathirvelu V, Majtan T, Frerman FE, Eaton GR, Eaton SS (2011) Electron transfer flavoprotein domain II orientation monitored using double electron-electron resonance between an enzymatically reduced, native FAD cofactor, and spin labels. Protein Sci 20(3):610–620. Scholar
  47. 47.
    Song L, Larion M, Chamoun J, Bonora M, Fajer PG (2010) Distance and dynamics determination by W-band DEER and W-band ST-EPR. Eur Biophys J 39(4):711–719. Scholar
  48. 48.
    Cruickshank PA, Bolton DR, Robertson DA, Hunter RI, Wylde RJ, Smith GM (2009) A kilowatt pulsed 94 GHz electron paramagnetic resonance spectrometer with high concentration sensitivity, high instantaneous bandwidth, and low dead time. Rev Sci Instrum 80(10):103102. Scholar
  49. 49.
    Hertel MM, Denysenkov VP, Bennati M, Prisner TF (2005) Pulsed 180-GHz EPR/ENDOR/PELDOR spectroscopy. Magn Reson Chem 43:S248–S255. Scholar
  50. 50.
    Alvarez FJ, Orelle C, Davidson AL (2010) Functional reconstitution of an ABC transporter in nanodiscs for use in electron paramagnetic resonance spectroscopy. J Am Chem Soc 132(28):9513–9515. Scholar
  51. 51.
    Jeschke G, Koch A, Jonas U, Godt A (2002) Direct conversion of EPR dipolar time evolution data to distance distributions. J Magn Reson 155(1):72–82. Scholar
  52. 52.
    Chiang YW, Borbat PP, Freed JH (2005) The determination of pair distance distributions by pulsed ESR using Tikhonov regularization. J Magn Reson 172(2):279–295CrossRefPubMedGoogle Scholar
  53. 53.
    Jeschke G, Panek G, Godt A, Bender A, Paulsen H (2004) Data analysis procedures for pulse ELDOR measurements of broad distance distributions. Appl Magn Reson 26:223–244CrossRefGoogle Scholar
  54. 54.
    Jeschke G, Chechik V, Ionita P, Godt A, Zimmermann H, Banham J, Timmel CR, Hilger D, Jung H (2006) DeerAnalysis2006 – a comprehensive software package for analyzing pulsed ELDOR data. Appl Magn Res 30(3–4):473–498CrossRefGoogle Scholar
  55. 55.
    Twomey S (1963) On the numerical solution of Fredholm integral equations of the first kind by the inversion of the linear system produced by quadrature. J ACM 10(1):97–101. Scholar
  56. 56.
    Tikhonov AN (1963) Solution of incorrectly formulated problems and the regularization method. Soviet Math Dokl 4:1035–1038Google Scholar
  57. 57.
    Press WH, Vetterling WT, Teukolsky SA, Flannery BP (1994) Numerical recipes in FORTRAN—the art of scientific computing 2nd Ed. (W. H. Press, W. T. Vetterling, S. A. Teukolsky and B. P. Flannery), pp 799–803. Scholar
  58. 58.
    Chiang YW, Borbat PP, Freed JH (2005) Maximum entropy: a complement to Tikhonov regularization for determination of pair distance distributions by pulsed ESR. J Magn Reson 177(2):184–196. Scholar
  59. 59.
    Sen KI, Logan TM, Fajer PG (2007) Protein dynamics and monomer-monomer interactions in AntR activation by electron paramagnetic resonance and double electron-electron resonance. Biochemistry 46(41):11639–11649. Scholar
  60. 60.
    Borbat PP, McHaourab HS, Freed JH (2002) Protein structure determination using long-distance constraints from double-quantum coherence ESR: study of T4 lysozyme. J Am Chem Soc 124(19):5304–5314CrossRefPubMedGoogle Scholar
  61. 61.
    Brandon S, Beth AH, Hustedt EJ (2012) The global analysis of DEER data. J Magn Reson 218:93–104. Scholar
  62. 62.
    Stein RA, Beth AH, Hustedt EJ (2015) A straightforward approach to the analysis of double electron-electron resonance data. Methods Enzymol 563:531–567. Scholar
  63. 63.
    Dewson G, Kratina T, Sim HW, Puthalakath H, Adams JM, Colman PM, Kluck RM (2008) To trigger apoptosis, Bak exposes its BH3 domain and homodimerizes via BH3:groove interactions. Mol Cell 30(3):369–380. Scholar
  64. 64.
    Dewson G, Ma S, Frederick P, Hockings C, Tan I, Kratina T, Kluck RM (2012) Bax dimerizes via a symmetric BH3:groove interface during apoptosis. Cell Death Differ 19(4):661–670. Scholar
  65. 65.
    Czabotar PE, Westphal D, Dewson G, Ma S, Hockings C, Fairlie WD, Lee EF, Yao S, Robin AY, Smith BJ, Huang DC, Kluck RM, Adams JM, Colman PM (2013) Bax crystal structures reveal how BH3 domains activate Bax and nucleate its oligomerization to induce apoptosis. Cell 152(3):519–531. Scholar
  66. 66.
    Kim H, Tu HC, Ren D, Takeuchi O, Jeffers JR, Zambetti GP, Hsieh JJ, Cheng EH (2009) Stepwise activation of BAX and BAK by tBID, BIM, and PUMA initiates mitochondrial apoptosis. Mol Cell 36(3):487–499. Scholar
  67. 67.
    Saito M, Korsmeyer SJ, Schlesinger PH (2000) BAX-dependent transport of cytochrome c reconstituted in pure liposomes. Nat Cell Biol 2(8):553–555. Scholar
  68. 68.
    Pavlov EV, Priault M, Pietkiewicz D, Cheng EH, Antonsson B, Manon S, Korsmeyer SJ, Mannella CA, Kinnally KW (2001) A novel, high conductance channel of mitochondria linked to apoptosis in mammalian cells and Bax expression in yeast. J Cell Biol 155(5):725–731. Scholar
  69. 69.
    Dejean LM, Ryu SY, Martinez-Caballero S, Teijido O, Peixoto PM, Kinnally KW (2010) MAC and Bcl-2 family proteins conspire in a deadly plot. Biochim Biophys Acta. Scholar
  70. 70.
    Kuwana T, Olson NH, Kiosses WB, Peters B, Newmeyer DD (2016) Pro-apoptotic Bax molecules densely populate the edges of membrane pores. Sci Rep 6:27299. Scholar
  71. 71.
    Grosse L, Wurm CA, Bruser C, Neumann D, Jans DC, Jakobs S (2016) Bax assembles into large ring-like structures remodeling the mitochondrial outer membrane in apoptosis. EMBO J 35(4):402–413. Scholar
  72. 72.
    Salvador-Gallego R, Mund M, Cosentino K, Schneider J, Unsay J, Schraermeyer U, Engelhardt J, Ries J, Garcia-Saez AJ (2016) Bax assembly into rings and arcs in apoptotic mitochondria is linked to membrane pores. EMBO J 35(4):389–401. Scholar
  73. 73.
    Schrodinger, LLC (2010) The PyMOL molecular graphics system, version 1.3Google Scholar
  74. 74.
    Moldoveanu T, Liu Q, Tocilj A, Watson M, Shore G, Gehring K (2006) The X-ray structure of a BAK homodimer reveals an inhibitory zinc binding site. Mol Cell 24(5):677–688. Scholar
  75. 75.
    Brouwer JM, Westphal D, Dewson G, Robin AY, Uren RT, Bartolo R, Thompson GV, Colman PM, Kluck RM, Czabotar PE (2014) Bak core and latch domains separate during activation, and freed core domains form symmetric homodimers. Mol Cell 55(6):938–946. Scholar
  76. 76.
    Hustedt EJ, Beth AH (1999) Nitroxide spin-spin interactions: applications to protein structure and dynamics. Annu Rev Biophys Biomol Struct 28:129–153CrossRefGoogle Scholar
  77. 77.
    Arfken G (1970) Mathematical methods for physicists, 2nd edn. Academic Press, New York, pp 178–183Google Scholar
  78. 78.
  79. 79.
    Liu X, Zou H, Slaughter C, Wang X (1997) DFF, a heterodimeric protein that functions downstream of caspase-3 to trigger DNA fragmentation during apoptosis. Cell 89(2):175–184 S0092-8674(00)80197-XCrossRefGoogle Scholar
  80. 80.
    Oh KJ, Barbuto S, Meyer N, Kim RS, Collier RJ, Korsmeyer SJ (2005) Conformational changes in BID, a pro-apoptotic BCL-2 family member, upon membrane binding. A site-directed spin labeling study. J Biol Chem 280(1):753–767CrossRefPubMedGoogle Scholar
  81. 81.
    Lutter M, Fang M, Luo X, Nishijima M, Xie X, Wang X (2000) Cardiolipin provides specificity for targeting of tBid to mitochondria. Nat Cell Biol 2(10):754–761CrossRefPubMedGoogle Scholar
  82. 82.
    Ardail D, Privat JP, Egret-Charlier M, Levrat C, Lerme F, Louisot P (1990) Mitochondrial contact sites. Lipid composition and dynamics. J Biol Chem 265(31):18797–18802PubMedGoogle Scholar
  83. 83.
    Oh KJ, Barbuto S, Pitter K, Morash J, Walensky LD, Korsmeyer SJ (2006) A membrane-targeted BID BCL-2 homology 3 peptide is sufficient for high potency activation of BAX in vitro. J Biol Chem 281(48):36999–37008. Scholar
  84. 84.
    Böttcher CJF, van Gent CM, Pries C (1961) A rapid and sensitive sub-micro phosphorus determination. Anal Chim Acta 24:203–204CrossRefGoogle Scholar
  85. 85.
    Eaton SS, Eaton GR (2005) Measurement of distances between electron spins using pulsed EPR. Biomedical EPR. Part B: Methodology, instrumentation, and dynamics. Springer, Boston, MA, USACrossRefGoogle Scholar
  86. 86.
    Reginsson GW, Hunter RI, Cruickshank PAS, Bolton DR, Sigurdsson ST, Smith GM, Schiemann O (2012) W-band PELDOR with 1 kW microwave power: molecular geometry, flexibility and exchange coupling. J Magn Reson 216:175–182. Scholar
  87. 87.
    Denysenkov VP, Prisner TF, Stubbe J, Bennati M (2006) High-field pulsed electron-electron double resonance spectroscopy to determine the orientation of the tyrosyl radicals in ribonucleotide reductase. Proc Natl Acad Sci U S A 103(36):13386–13390. Scholar
  88. 88.
    Polyhach Y, Godt A, Bauer C, Jeschke G (2007) Spin pair geometry revealed by high-field DEER in the presence of conformational distributions. J Magn Reson 185(1):118–129. Scholar
  89. 89.
    Gordon-Grossman M, Kaminker I, Gofman Y, Shai Y, Goldfarb D (2011) W-Band pulse EPR distance measurements in peptides using Gd3+-dipicolinic acid derivatives as spin labels. Phys Chem Chem Phys 13(22):10771–10780. Scholar
  90. 90.
    Liu X, Kim CN, Yang J, Jemmerson R, Wang X (1996) Induction of apoptotic program in cell-free extracts: requirement for dATP and cytochrome c. Cell 86(1):147–157CrossRefPubMedGoogle Scholar
  91. 91.
    Glasoe PK, Long FA (1960) Use of glass electrodes to measure acidities in deuterium OXIDE1,2. J Phys Chem 64(1):188–190. Scholar
  92. 92.
    Fajer PG, Brown L, Song L (2007) Practical pulsed dipolar ESR (DEER). Biol Magn Reson 27:95–128CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Tirtha Mandal
    • 2
    • 1
  • Eric J. Hustedt
    • 3
  • Likai Song
    • 4
  • Kyoung Joon Oh
    • 1
    Email author
  1. 1.Department of Biochemistry & Molecular Biology, The Chicago Medical SchoolRosalind Franklin University of Medicine and ScienceNorth ChicagoUSA
  2. 2.Department of BiologyMassachusetts Institute of TechnologyCambridgeUSA
  3. 3.Department of Molecular Physiology and BiophysicsVanderbilt University School of MedicineNashvilleUSA
  4. 4.National High Magnetic Field LaboratoryFlorida State UniversityTallahasseeUSA

Personalised recommendations