Hydrogen Bonding of Tryptophan Radicals Revealed by EPR at 700 GHz

Overview

Journal J Am Chem Soc

Publisher American Chemical Society

Specialty Chemistry

Date 2011 Oct 20

PMID 22007694

Citations 21

Authors

Stefan Stoll

Hannah S Shafaat

J Krzystek

Andrew Ozarowski

Michael J Tauber

Judy E Kim

R David Britt

Affiliations

Soon will be listed here.

Abstract

Redox-active tryptophans are important in biological electron transfer and redox biochemistry. Proteins can tune the electron transfer kinetics and redox potentials of tryptophan via control of the protonation state and the hydrogen-bond strength. We examine the local environment of two neutral tryptophan radicals (Trp108 on the solvent-exposed surface and Trp48 buried in the hydrophobic core) in two azurin variants. Ultrahigh-field EPR spectroscopy at 700 GHz and 25 T allowed complete resolution of all of the principal components of the g tensors of the two radicals and revealed significant differences in the g tensor anisotropies. The spectra together with (2)H ENDOR spectra and supporting DFT calculations show that the g tensor anisotropy is directly diagnostic of the presence or absence as well as the strength of a hydrogen bond to the indole nitrogen. The approach is a powerful one for identifying and characterizing hydrogen bonds that are critical in the regulation of tryptophan-assisted electron transfer and tryptophan-mediated redox chemistry in proteins.

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References

Pogni R, Baratto M, Giansanti S, Teutloff C, Verdin J, Valderrama B . Tryptophan-based radical in the catalytic mechanism of versatile peroxidase from Bjerkandera adusta. Biochemistry. 2005; 44(11):4267-74. DOI: 10.1021/bi047474l. View

Hammel K, Cullen D . Role of fungal peroxidases in biological ligninolysis. Curr Opin Plant Biol. 2008; 11(3):349-55. DOI: 10.1016/j.pbi.2008.02.003. View

Flores M, Isaacson R, Abresch E, Calvo R, Lubitz W, Feher G . Protein-cofactor interactions in bacterial reaction centers from Rhodobacter sphaeroides R-26: II. Geometry of the hydrogen bonds to the primary quinone formula by 1H and 2H ENDOR spectroscopy. Biophys J. 2006; 92(2):671-82. PMC: 1751397. DOI: 10.1529/biophysj.106.092460. View

Shih C, Museth A, Abrahamsson M, Blanco-Rodriguez A, Di Bilio A, Sudhamsu J . Tryptophan-accelerated electron flow through proteins. Science. 2008; 320(5884):1760-2. DOI: 10.1126/science.1158241. View

Pogni R, Baratto M, Teutloff C, Giansanti S, Ruiz-Duenas F, Choinowski T . A tryptophan neutral radical in the oxidized state of versatile peroxidase from Pleurotus eryngii: a combined multifrequency EPR and density functional theory study. J Biol Chem. 2006; 281(14):9517-26. DOI: 10.1074/jbc.M510424200. View

Brettel K, Byrdin M . Reaction mechanisms of DNA photolyase. Curr Opin Struct Biol. 2010; 20(6):693-701. DOI: 10.1016/j.sbi.2010.07.003. View

Connor H, Sturgeon B, Mottley C, Sipe Jr H, Mason R . L-tryptophan radical cation electron spin resonance studies: connecting solution-derived hyperfine coupling constants with protein spectral interpretations. J Am Chem Soc. 2008; 130(20):6381-7. PMC: 2644638. DOI: 10.1021/ja0780277. View

Langenbacher T, Immeln D, Dick B, Kottke T . Microsecond light-induced proton transfer to flavin in the blue light sensor plant cryptochrome. J Am Chem Soc. 2009; 131(40):14274-80. DOI: 10.1021/ja901628y. View

Wiertz F, Richter O, Ludwig B, de Vries S . Kinetic resolution of a tryptophan-radical intermediate in the reaction cycle of Paracoccus denitrificans cytochrome c oxidase. J Biol Chem. 2007; 282(43):31580-91. DOI: 10.1074/jbc.M705520200. View

10.

Colin J, Wiseman B, Switala J, Loewen P, Ivancich A . Distinct role of specific tryptophans in facilitating electron transfer or as [Fe(IV)=O Trp(*)] intermediates in the peroxidase reaction of Bulkholderia pseudomallei catalase-peroxidase: a multifrequency EPR spectroscopy investigation. J Am Chem Soc. 2009; 131(24):8557-63. DOI: 10.1021/ja901402v. View

11.

Smith A, Doyle W, Dorlet P, Ivancich A . Spectroscopic evidence for an engineered, catalytically active Trp radical that creates the unique reactivity of lignin peroxidase. Proc Natl Acad Sci U S A. 2009; 106(38):16084-9. PMC: 2752603. DOI: 10.1073/pnas.0904535106. View

12.

Kiryutin A, Morozova O, Kuhn L, Yurkovskaya A, Hore P . 1H and 13C hyperfine coupling constants of the tryptophanyl cation radical in aqueous solution from microsecond time-resolved CIDNP. J Phys Chem B. 2007; 111(38):11221-7. DOI: 10.1021/jp073385h. View

13.

Jasion V, Polanco J, Meharenna Y, Li H, Poulos T . Crystal structure of Leishmania major peroxidase and characterization of the compound i tryptophan radical. J Biol Chem. 2011; 286(28):24608-15. PMC: 3137036. DOI: 10.1074/jbc.M111.230524. View

14.

Gray H, Winkler J . Electron flow through metalloproteins. Biochim Biophys Acta. 2010; 1797(9):1563-72. DOI: 10.1016/j.bbabio.2010.05.001. View

15.

Yeh H, Gerfen G, Wang J, Tsai A, Wang L . Characterization of the peroxidase mechanism upon reaction of prostacyclin synthase with peracetic acid. Identification of a tyrosyl radical intermediate. Biochemistry. 2009; 48(5):917-28. PMC: 2849756. DOI: 10.1021/bi801382v. View

16.

Stoll S, Ozarowski A, Britt R, Angerhofer A . Atomic hydrogen as high-precision field standard for high-field EPR. J Magn Reson. 2010; 207(1):158-63. PMC: 2956851. DOI: 10.1016/j.jmr.2010.08.006. View

17.

Faller P, Goussias C, Rutherford A, Un S . Resolving intermediates in biological proton-coupled electron transfer: a tyrosyl radical prior to proton movement. Proc Natl Acad Sci U S A. 2003; 100(15):8732-5. PMC: 166381. DOI: 10.1073/pnas.1530926100. View

18.

Shafaat H, Leigh B, Tauber M, Kim J . Spectroscopic comparison of photogenerated tryptophan radicals in azurin: effects of local environment and structure. J Am Chem Soc. 2010; 132(26):9030-9. DOI: 10.1021/ja101322g. View

19.

Potsch S, Lendzian F, Ingemarson R, Hornberg A, Thelander L, Lubitz W . The iron-oxygen reconstitution reaction in protein R2-Tyr-177 mutants of mouse ribonucleotide reductase. Epr and electron nuclear double resonance studies on a new transient tryptophan radical. J Biol Chem. 1999; 274(25):17696-704. DOI: 10.1074/jbc.274.25.17696. View

20.

Bar G, Bennati M, Nguyen H, Ge J, Stubbe J, Griffin R . High-frequency (140-GHz) time domain EPR and ENDOR spectroscopy: the tyrosyl radical-diiron cofactor in ribonucleotide reductase from yeast. J Am Chem Soc. 2001; 123(15):3569-76. DOI: 10.1021/ja003108n. View