An introduction to protein 2D IR spectroscopy

Ultrafast Infrared Vibrational Spectroscopy

Volumn , Issue , 2013, Pages 361-403

  Baiz, Carlos R ^a   Reppert, Mike ^a   Tokmakoff, Andrei ^a  

^a MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

BIOLOGICAL MEMBRANES; CHARGE TRANSFER; CONFORMATIONS;

BIOLOGICAL FUNCTIONS; BIOLOGICAL PROCESS; CONFORMATIONAL CHANGE; CONFORMATIONAL DYNAMICS; PROTEIN CONFORMATIONAL CHANGES; STRUCTURAL DISORDERS; TRADITIONAL TECHNIQUES; TWO-DIMENSIONAL INFRARED (2D IR);

PROTEINS;

EID: 85051665564     PISSN: None     EISSN: None     Source Type: Book    
DOI: 10.1201/b13972     Document Type: Chapter

References (133)

1. Hamm P, Zanni M. 2011. Concepts and Methods of 2D Infrared Spectroscopy (Cambridge University Press, Cambridge, New York).
2. Cho M. 2009. Two-Dimensional Optical Spectroscopy (CRC Press, Boca Raton, FL).
3. Fayer MD. 2009. Dynamics of liquids, molecules, and proteins measured with ultrafast 2D IR vibrational echo chemical exchange spectroscopy. Annu Rev Phys Chem 60:21.
4. Middleton CT et al. 2012. Two-dimensional infrared spectroscopy reveals the complex behaviour of an amyloid fibril inhibitor. Nat Chem 4:355-360.
5. Kim YS, Liu L, Axelsen PH, Hochstrasser RM. 2009. 2D IR provides evidence for mobile water molecules in beta-amyloid fibrils. Proc Natl Acad Sci USA 106:17751-17756.
6. Lessing J et al. 2012. Identifying residual structure in intrinsically disordered systems: A 2D IR spectroscopic study of the GVGXPGVG peptide. J Am Chem Soc 134:5032-5035.
7. Ghosh A, Qiu J, DeGrado WF, Hochstrasser RM. 2011. Tidal surge in the M2 proton channel, sensed by 2D IR spectroscopy. Proc Natl Acad Sci USA 108:6115-6120.
8. Manor J et al. 2009. Gating mechanism of the influenza A M2 channel revealed by 1D and 2D IR spectroscopies. Structure 17:247-254.
9. Munoz V. 2007. Conformational dynamics and ensembles in protein folding. Annu Rev Bioph Biom 36: 395-412.
10. Kubelka J, Hofrichter J, Eaton WA. 2004. The protein folding “speed limit”. Curr Opin Struc Biol 14: 76-88.
11. Chung HS, Shandiz A, Sosnick TR, Tokmakoff A. 2008. Probing the folding transition state of ubiquitin mutants by temperature-jump-induced downhill unfolding. Biochemistry USA 47:13870-13877.
12. Smith AW et al. 2010. Melting of a beta-Hairpin peptide using isotope-edited 2D IR spectroscopy and simulations. J Phys Chem B 114:10913-10924.
13. Woutersen S, Mu Y, Stock G, Hamm P. 2001. Hydrogen-bond lifetime measured by time-resolved 2D IR spectroscopy: N-methylacetamide in methanol. Chem Phys 266:137-147.
14. Baiz CR, Peng CS, Reppert ME, Jones KC, Tokmakoff A. 2012. Coherent two-dimensional infrared spectroscopy: Quantitative analysis of protein secondary structure in solution. Analyst 137:1793-1799.
15. Wang L, Middleton CT, Zanni MT, Skinner JL. 2011. Development and validation of transferable amide I vibrational frequency maps for peptides. J Phys Chem B 115:3713-3724.
16. Jansen TL, Knoester J. 2006. A transferable electrostatic map for solvation effects on amide I vibrations and its application to linear and two-dimensional spectroscopy. J Chem Phys 124:044502.
17. Schmidt JR, Corcelli SA, Skinner JL. 2004. Ultrafast vibrational spectroscopy of water and aqueous N-methylacetamide: Comparison of different electronic structure/molecular dynamics approaches. J Chem Phys 121:8887-8896.
18. Bloem R, Dijkstra AG, Jansen TLC, Knoester J. 2008. Simulation of vibrational energy transfer in two-dimensional infrared spectroscopy of amide I and amide II modes in solution. J Chem Phys 129:055101.
19. Barth A. 2007. Infrared spectroscopy of proteins. Bba-Bioenergetics 1767:1073-1101.
20. Barth A, Zscherp C. 2002. What vibrations tell us about proteins. Q Rev Biophys 35:369-430.
21. Jackson M, Mantsch HH. 1995. The use and misuse of FTIR spectroscopy in the determination of protein-structure. Crit Rev Biochem Mol 30:95-120.
22. Krimm S, Bandekar J. 1986. Vibrational spectroscopy and conformation of peptides, polypeptides, and proteins. Adv Protein Chem 38:181-364.
23. Davydov AS. 1971. Theory of Molecular Excitons (Plenum Press, New York).
24. Chung HS, Tokmakoff A. 2006. Visualization and characterization of the infrared active amide I vibrations of proteins. J Phys Chem B 110:2888-2898.
25. Cheatum CM, Tokmakoff A, Knoester J. 2004. Signatures of beta-sheet secondary structures in linear and two-dimensional infrared spectroscopy. J Chem Phys 120:8201-8215.
26. Torii H, Tasumi M. 1992. 3-Dimensional doorway-state theory for analyses of absorption-bands of many-oscillator systems. J Chem Phys 97:86-91.
27. Torii H, Tasumi M. 1992. Application of the 3-dimensional doorway-state theory to analyses of the amide-I infrared bands of globular-proteins. J Chem Phys 97:92-98.
28. Abramavicius D, Zhuang W, Mukamel S. 2004. Peptide secondary structure determination by three-pulse coherent vibrational spectroscopies: A simulation study. J Phys Chem B 108:18034-18045.
29. Demirdoven N et al. 2004. Two-dimensional infrared spectroscopy of antiparallel beta-sheet secondary structure. J Am Chem Soc 126:7981-7990.
30. Ganim Z et al. 2008. Amide I two-dimensional infrared spectroscopy of proteins. Acc Chem Res 41: 432-441.
31. Ganim Z, Tokmakoff A. 2006. Spectral signatures of heterogeneous protein ensembles revealed by MD simulations of 2D IR spectra. Biophys J 91:2636-2646.
32. Nevskaya NA, Chirgadze YN. 1976. Infrared-spectra and resonance interactions of amide-one and amide-2 vibrations of alpha-helix. Biopolymers 15:637-648.
33. Woutersen S, Hamm P. 2002. Nonlinear two-dimensional vibrational spectroscopy of peptides. J Phys.: Condens Matter 14:1035-1062-1035-1062.
34. Wang JP, Hochstrasser RM. 2004. Characteristics of the two-dimensional infrared spectroscopy of helices from approximate simulations and analytic models. Chem Phys 297:195-219.
35. Kubelka J, Silva RAGD, Keiderling TA. 2002. Discrimination between peptide 3(10)- and alpha-helices. Theoretical analysis of the impact of alpha-methyl substitution on experimental spectra. J Am Chem Soc 124:5325-5332.
36. Silva RAGD et al. 2002. Discriminating 3(10)- from alpha helices: Vibrational and electronic CD and IR absorption study of related Aib-containing oligopeptides. Biopolymers 65:229-243.
37. Maekawa H, Toniolo C, Moretto A, Broxterman QB, Ge NH. 2006. Different spectral signatures of octapeptide 3(10) and alpha-helices revealed by two-dimensional infrared spectroscopy. J Phys Chem B 110:5834-5837.
38. Maekawa H, Toniolo C, Broxterman QB, Ge NH. 2007. Two-dimensional infrared spectral signatures of 3(10)- and alpha-helical peptides. J Phys Chem B 111:3222-3235.
39. Wang JP. 2008. Conformational dependence of anharmonic vibrations in peptides: Amide-I modes in model dipeptide. J Phys Chem B 112:4790-4800.
40. Karjalainen EL, Ravi HK, Barth A. 2011. Simulation of the amide I absorption of stacked beta-sheets. J Phys Chem B 115:749-757.
41. Kubelka J, Keiderling TA. 2001. Differentiation of beta-sheet-forming structures: Ab initio-based simulations of IR absorption and vibrational CD for model peptide and protein beta-sheets. J Am Chem Soc 123:12048-12058.
42. Lee C, Cho MH. 2004. Local amide I mode frequencies and coupling constants in multiple-stranded antiparallel beta-sheet polypeptides. J Phys Chem B 108:20397-20407.
43. Moore WH, Krimm S. 1975. Transition dipole coupling in amide I modes of beta polypeptides. Proc Natl Acad Sci USA 72:4933-4935.
44. Maekawa H, Ge NH. 2010. Comparative study of electrostatic models for the amide-I and -II modes: Linear and two-dimensional infrared spectra. J Phys Chem B 114:1434-1446.
45. Choi JH, Kim JS, Cho MH. 2005. Amide I vibrational circular dichroism of polypeptides: Generalized fragmentation approximation method. J Chem Phys 122:174903.
46. DeFlores LP, Ganim Z, Nicodemus RA, Tokmakoff A. 2009. Amide I "-II” 2D IR spectroscopy provides enhanced protein secondary structural sensitivity. J Am Chem Soc 131:3385-3391.
47. Middleton CT, Buchanan LE, Dunkelberger EB, Zanni MT. 2011. Utilizing lifetimes to suppress random coil features in 2D IR spectra of peptides. J Phys Chem Lett 2:2357-2361.
48. Torii H, Tasumi M. 1992. Model-calculations on the amide-I infrared bands of globular-proteins. J Chem Phys 96:3379-3387.
49. Wang L et al. 2011. 2D IR spectroscopy of human amylin fibrils reflects stable beta-sheet structure. J Am Chem Soc 133:16062-16071.
50. Middleton CT, Woys AM, Mukherjee SS, Zanni MT. 2010. Residue-specific structural kinetics of proteins through the union of isotope labeling, mid-IR pulse shaping, and coherent 2D IR spectroscopy. Methods 52:12-22.
51. Shim SH et al. 2009. Two-dimensional IR spectroscopy and isotope labeling defines the pathway of amyloid formation with residue-specific resolution. Proc Natl Acad Sci USA 106:6614-6619.
52. Gnanakaran S, Hochstrasser RM. 2001. Conformational preferences and vibrational frequency distributions of short peptides in relation to multidimensional infrared spectroscopy. J Am Chem Soc 123:12886-12898.
53. Ham S, Kim JH, Lee H, Cho MH. 2003. Correlation between electronic and molecular structure distortions and vibrational properties. II. Amide I modes of NMA-nD(2)O complexes. J Chem Phys 118:3491-3498.
54. Hamm P, Lim MH, Hochstrasser RM. 1998. Structure of the amide I band of peptides measured by femtosecond nonlinear-infrared spectroscopy. J Phys Chem B 102:6123-6138.
55. Kim YS, Hochstrasser RM. 2009. Applications of 2D IR spectroscopy to peptides, proteins, and hydrogen-bond dynamics. J Phys Chem B 113:8231-8251.
56. Decatur SM. 2006. Elucidation of residue-level structure and dynamics of polypeptides via isotope-edited infrared spectroscopy. Acc Chem Res 39:169-175.
57. Barber-Armstrong W, Donaldson T, Wijesooriya H, Silva RAGD, Decatur SM. 2004. Empirical relationships between isotope-edited IR spectra and helix geometry in model peptides. J Am Chem Soc 126:2339-2345.
58. Fang C, Hochstrasser RM. 2005. Two-dimensional infrared spectra of the C-13=O-18 isotopomers of alanine residues in an alpha-helix. J Phys Chem B 109:18652-18663.
59. Bandekar J. 1992. Amide modes and protein conformation. Biochim Biophys Acta 1120:123-143.
60. Barth A. 2000. The infrared absorption of amino acid side chains. Prog Biophys Mol Bio 74:141-173.
61. Nagarajan S et al. 2011. Differential ordering of the protein backbone and side chains during protein folding revealed by site-specific recombinant infrared probes. J Am Chem Soc 133:20335-20340.
62. Lindquist BA, Furse KE, Corcelli SA. 2009. Nitrile groups as vibrational probes of biomolecular structure and dynamics: An overview. Phys Chem Chem Phys 11:8119-8132.
63. Oh KI et al. 2008. Nitrile and thiocyanate IR probes: Molecular dynamics simulation studies. J Chem Phys 128:154504.
64. Choi JH, Oh KI, Cho MH. 2008. Azido-derivatized compounds as IR probes of local electrostatic environment: Theoretical studies. J Chem Phys 129:174512.
65. Thielges MC et al. 2011. Two-dimensional IR spectroscopy of protein dynamics using two vibrational labels: A site-specific genetically encoded unnatural amino acid and an active site ligand. J Phys Chem B 115:11294-11304.
66. Hendrickson WA, Horton JR, Lemaster DM. 1990. Selenomethionyl proteins produced for analysis by multiwavelength anomalous diffraction (Mad)-A vehicle for direct determination of 3-dimensional structure. Embo J 9:1665-1672.
67. Wang L, Xie J, Schultz PG. 2006. Expanding the genetic code. Annu Rev Bioph Biom 35:225-249.
68. Hill JR et al. 1994. Vibrational dynamics of carbon-monoxide at the active-site of myoglobin-Picosecond infrared free-electron laser pump-probe experiments. J Phys Chem USA 98:11213-11219.
69. Fayer MD. 2001. Fast protein dynamics probed with infrared vibrational echo experiments. Annu Rev Phys Chem 52:315-356.
70. King JT, Arthur EJ, Brooks CL, Kubarych KJ. 2012. Site-specific hydration dynamics of globular proteins and the role of constrained water in solvent exchange with amphiphilic cosolvents. J Phys Chem B 116:5604-5611.
71. Hayashi T, Zhuang W, Mukamel S. 2005. Electrostatic DFT map for the complete vibrational amide band of NMA. J Phys Chem A 109:9747-9759.
72. Jansen TLC, Knoester J. 2009. Waiting time dynamics in two-dimensional infrared spectroscopy. Acc Chem Res 42:1405-1411.
73. Mukamel S. 1999. Principles of Nonlinear Optical Spectroscopy (Oxford University Press, USA).
74. Petersen PB, Tokmakoff A. 2010. Source for ultrafast continuum infrared and terahertz radiation. Opt Lett 35:1962-1964.
75. Baiz CR, Kubarych KJ. 2011. Ultrabroadband detection of a mid-IR continuum by chirped-pulse upconversion. Opt Lett 36:187-189.
76. Zanni MT, Ge NH, Kim YS, Hochstrasser RM. 2001. Two-dimensional IR spectroscopy can be designed to eliminate the diagonal peaks and expose only the crosspeaks needed for structure determination. Proc Natl Acad Sci 98:11265-11265.
77. Khalil M, Demirdoven N, Tokmakoff A. 2003. Coherent 2D IR spectroscopy: Molecular structure and dynamics in solution. J Phys Chem A 107:5258-5279.
78. Roberts ST, Loparo JJ, Tokmakoff A. 2006. Characterization of spectral diffusion from two-dimensional line shapes. J Chem Phys 125:084502.
79. Gruebele M. 1999. The fast protein folding problem. Annu Rev Phys Chem 50:485-516.
80. Bredenbeck J, Hamm P. 2007. Transient 2D IR spectroscopy: Towards a molecular movie. Chimia 61:45-46.
81. Chung HS, Khalil M, Smith AW, Tokmakoff A. 2007. Transient two-dimensional IR spectrometer for probing nanosecond temperature-jump kinetics. Rev Sci Instrum 78:063101.
82. Callender R, Dyer RB. 2002. Probing protein dynamics using temperature jump relaxation spectroscopy. Curr Opin Struc Biol 12:628-633.
83. Dumont C, Emilsson T, Gruebele M. 2009. Reaching the protein folding speed limit with large, sub-microsecond pressure jumps. Nat Methods 6:515-U570.
84. Gutman M, Nachliel E. 1990. The dynamic aspects of proton-transfer processes. Biochim Biophys Acta 1015:391-414.
85. Fabian H, Naumann D. 2004. Methods to study protein folding by stopped-flow FT-IR. Methods 34: 28-40.
86. Baiz C, Nee M, McCanne R, Kubarych K. 2008. Ultrafast nonequilibrium Fourier-transform two-dimensional infrared spectroscopy. Opt Lett 33:2533-2535.
87. Xiong W et al. 2009. Transient 2D IR spectroscopy of charge injection in dye-sensitized nanocrystalline thin films. J Am Chem Soc 131:18040
88. Jones KC, Ganim Z, Peng CS, Tokmakoff A. 2012. Transient two-dimensional spectroscopy with linear absorption corrections applied to temperature-jump two-dimensional infrared. J Opt Soc Am B 29: 118-129.
89. Jones KC, Ganim Z, Tokmakoff A. 2009. Heterodyne-detected dispersed vibrational echo spectroscopy. J Phys Chem A 113:14060-14066.
90. Marecek J et al. 2007. A simple and economical method for the production of C-13, O-18-labeled Fmoc-amino acids with high levels of enrichment: Applications to isotope-edited IR studies of proteins. Org Lett 9:4935-4937.
91. Bouř P, Keiderling TA. 2003. Empirical modeling of the peptide amide I band IR intensity in water solution. J Chem Phys 119:11253-11262.
92. Watson TM, Hirst JD. 2005. Theoretical studies of the amide I vibrational frequencies of [Leu]-enkephalin. Mol Phys 103:1531-1546.
93. Jansen TL, Dijkstra AG, Watson TM, Hirst JD, Knoester J. 2006. Modeling the amide I bands of small peptides. J Chem Phys 125:044312.
94. Cai KC, Han C, Wang JP. 2009. Molecular mechanics force field-based map for peptide amide-I mode in solution and its application to alanine di- and tripeptides. Phys Chem Chem Phys 11:9149-9159.
95. Lin YS, Shorb JM, Mukherjee P, Zanni MT, Skinner JL. 2009. Empirical amide I vibrational frequency map: Application to 2D IR line shapes for isotope-edited membrane peptide bundles. J Phys Chem B 113:592-602.
96. Roy S et al. 2011. Solvent and conformation dependence of amide I vibrations in peptides and proteins containing proline. J Chem Phys 135:234507.
97. Van Amerongen H, Valkunas L, Van Grondelle R. 2000. Photosynthetic Excitons (World Scientific), ISBN 9810232802.
98. Moffitt W. 1956. Optical rotatory dispersion of helical polymers. J Chem Phys 25:467-478.
99. Miyazawa T. 1960. Perturbation treatment of the characteristic vibrations of polypeptide chains in various configurations. J Chem Phys 32:1647-1652.
100. Krimm S, Abe Y. 1972. Intermolecular interaction effects in amide I vibrations of beta polypeptides. Proc Natl Acad Sci USA 69:2788-2792.
101. Hamm P, Woutersen S. 2002. Coupling of the amide I modes of the glycine dipeptide. B Chem Soc Jpn 75:985-988.
102. Sung J, Silbey RJ. 2001. Four wave mixing spectroscopy for a multilevel system. J Chem Phys 115: 9266-9287.
103. Khalil M, Demirdoven N, Tokmakoff A. 2003. Obtaining absorptive line shapes in two-dimensional infrared vibrational correlation spectra. Phys Rev Lett 90: 047401.
104. Golonzka O, Tokmakoff A. 2001. Polarization-selective third-order spectroscopy of coupled vibronic states. J Chem Phys 115:297-309.
105. Jonas DM. 2003. Two-dimensional femtosecond spectroscopy. Annu Rev Phys Chem 54:425-463.
106. Faeder SMG, Jonas DM. 1999. Two-dimensional electronic correlation and relaxation spectra: Theory and model calculations. J Phys Chem A 103:10489-10505.
107. Torii H. 2006. Effects of intermolecular vibrational coupling and liquid dynamics on the polarized Raman and two-dimensional infrared spectral profiles of liquid N, N-dimethylformamide analyzed with a time-domain computational method. J Phys Chem A 110:4822-4832.
108. Jansen TL, Knoester J. 2006. Nonadiabatic effects in the two-dimensional infrared spectra of peptides: Application to alanine dipeptide. J Phys Chem B 110:22910-22916.
109. Gaigeot MP. 2010. Theoretical spectroscopy of floppy peptides at room temperature. A DFTMD perspective: Gas and aqueous phase. Phys Chem Chem Phys 12:3336-3359.
110. Ingrosso F, Monard G, Farag MH, Bastida A, Ruiz-Lopez MF. 2011. Importance of polarization and charge transfer effects to model the infrared spectra of peptides in solution. J Chem Theory Comput 7: 1840-1849.
111. Jeon J, Cho M. 2010. Direct quantum mechanical/molecular mechanical simulations of two-dimensional vibrational responses: N-methylacetamide in water. New J Phys 12:065001.
112. Gorbunov RD, Kosov DS, Stock G. 2005. Ab initio-based exciton model of amide I vibrations in peptides: Definition, conformational dependence, and transferability. J Chem Phys 122:224904.
113. Byler DM, Susi H. 1986. Examination of the secondary structure of proteins by deconvolved FTIR spectra. Biopolymers 25:469-487.
114. DeFlores LP, Ganim Z, Ackley SF, Chung HS, Tokmakoff A. 2006. The anharmonic vibrational potential and relaxation pathways of the amide I and II modes of N-methylacetamide. J Phys Chem B 110: 18973-18980.
115. Pande V. 2011. Folding@home: Sustained petaflops for production calculations today, exaflops soon? Abstr Pap Am Chem S 242.
116. Pande V. 2010. Simulating protein folding in vitro and in vivo. Biochem Cell Biol 88:409-409.
117. Lindorff-Larsen K, Piana S, Dror RO, Shaw DE. 2011. How fast-folding proteins fold. Science 334: 517-520.
118. Chung HS, Ganim Z, Jones KC, Tokmakoff A. 2007. Transient 2D IR spectroscopy of ubiquitin unfolding dynamics. Proc Natl Acad Sci USA 104:14237-14242.
119. Cochran AG, Skelton NJ, Starovasnik MA. 2001. Tryptophan zippers: Stable, monomeric beta-hairpins. Proc Natl Acad Sci USA 98:5578-5583.
120. Mukherjee P, Kass I, Arkin IT, Zanni MT. 2006. Structural disorder of the CD3 xi transmembrane domain studied with 2D IR spectroscopy and molecular dynamics simulations. J Phys Chem B 110:24740-24749.
121. Remorino A, Korendovych IV, Wu YB, DeGrado WF, Hochstrasser RM. 2011. Residue-specific vibrational echoes yield 3D structures of a transmembrane helix dimer. Science 332:1206-1209.
122. Hamm P, Helbing J, Bredenbeck J. 2008. Two-dimensional infrared spectroscopy of photoswitchable peptides. Annu Rev Phys Chem 59:291-317.
123. Chung HS, Tokmakoff A. 2008. Temperature-dependent downhill unfolding of ubiquitin. II. Modeling the free energy surface. Proteins 72:488-497.
124. Chung HS, Tokmakoff A. 2008. Temperature-dependent downhill unfolding of ubiquitin. I. Nanosecond-to-millisecond resolved nonlinear infrared spectroscopy. Proteins 72:474-487.
125. Bredenbeck J, Helbing J, Nienhaus K, Nienhaus GU, Hamm P. 2007. Protein ligand migration mapped by nonequilibrium 2D IR exchange spectroscopy. Proc Natl Acad Sci USA 104:14243-14248.
126. Finkelstein IJ, Ishikawa H, Kim S, Massari AM, Fayer MD. 2007. Substrate binding and protein conformational dynamics measured by 2D IR vibrational echo spectroscopy. Proc Natl Acad Sci USA 104: 2637-2642.
127. Bandaria JN et al. 2010. Characterizing the dynamics of functionally relevant complexes of formate dehydrogenase. Proc Natl Acad Sci USA 107:17974-17979.
128. Chung JK, Thielges MC, Fayer MD. 2011. Dynamics of the folded and unfolded villin headpiece (HP35) measured with ultrafast 2D IR vibrational echo spectroscopy. Proc Natl Acad Sci USA 108:3578-3583.
129. Urbanek DC, Vorobyev DY, Serrano AL, Gai F, Hochstrasser RM. 2010. The two-dimensional vibrational echo of a nitrile probe of the Villin HP35 protein. J Phys Chem Lett 1:3311-3315.
130. Fang C et al. 2008. Two-dimensional infrared spectra reveal relaxation of the nonnucleoside inhibitor TMC278 complexed with HIV-1 reverse transcriptase. Proc Natl Acad Sci USA 105:1472-1477.
131. Ganim Z, Jones KC, Tokmakoff A. 2010. Insulin dimer dissociation and unfolding revealed by amide I two-dimensional infrared spectroscopy. Phys Chem Chem Phys 12:3579-3588.
132. Ganim Z, Tokmakoff A, Vaziri A. 2011. Vibrational excitons in ionophores: Experimental probes for quantum coherence-assisted ion transport and selectivity in ion channels. New J Phys 13:113030.
133. Torii H, Tasumi M. 1998. Ab initio molecular orbital study of the amide I vibrational interactions between the peptide groups in di- and tripeptides and considerations on the conformation of the extended helix. J Raman Spectrosc 29:81-86.