Some aspects of the NMR chemical shift/structure correlation in the structural characterization of polymers and biopolymers

Polymer Journal

Volumn 44, Issue 8, 2012, Pages 734-747

  Ando, Isao ^a  

^a TOKYO INSTITUTE OF TECHNOLOGY   (Japan)

Author keywords

biopolymer; conformation; higher order structure; hydrogen bond structure; NMR chemical shift; stereochemical structure

Indexed keywords

BOND STRUCTURES; HIGHER-ORDER STRUCTURE; NMR CHEMICAL SHIFTS; POLYMERS AND BIOPOLYMERS; SOLID STATE NMR; STEREOCHEMICAL STRUCTURES; STRUCTURAL CHARACTERIZATION;

BIOMOLECULES; BIOPOLYMERS; CHEMICAL SHIFT; CONFORMATIONS; HYDROGEN BONDS;

POLYMERS;

EID: 84864687818     PISSN: 00323896     EISSN: 13490540     Source Type: Journal    
DOI: 10.1038/pj.2012.95     Document Type: Conference Paper

References (108)

1. Gutowsky, H. S., Saika, A., Takeda, M. & Woessner, D. E. Proton magnetic resonance studies on natural rubber. II. Line shape and T1 measurements. J. Chem. Phys. 27, 534 (1957).
2. Meyer, L. H., Saika, A. & Gutowsky, H. S. Electron distribution in molecules. III. The proton magnetic spectra of simple organic groups. J. Am. Chem. Soc. 75, 4567 (1953).
3. Bovey, F. A. & Tiers, G. V. D. Polymer NSR spectroscopy. II. The high resolution spectra of methyl methacrylate polymers prepared with free radical and anionic initiators. J. Polym. Sci. 44, 173 (1960).
4. Nishioka, A., Watanabe, H., Yamaguchi, I. & Shimizu, H. High resolution NMR spectra of isotactic and syndiotactic polymethyl methacrylate in chloroform solution. J. Polym. Sci. 45, 232 (1960).
5. Johnsen, U. & Tessmar, K. Wissenschaftliche Kurzberichte Hochaufgelöste Kernresonanzspektren von eutaktischen Polymethylmethacrylaten. Kolloid-Z. 168, 160 (1960).
6. Ando, I. & Webb, G. A. Theory of NMR Parameters (Academic Press, London, 1983).
7. Ando, I. & Asakura, T. Chemical shift calculations and stereochemical structures of synthetic polymers. Ann. Repts. NMR Spectrosc. 10A, 81, 1980).
8. Ando, I. & Asakura, T. (ed.) Solid State NMR of Polymers (Elsevier Science, Amsterdam, 1998).
9. Ramsey, N. F. Magnetic shielding of nuclei in molecules. Phys. Rev. 78, 699 (1950).
10. Ramsey, N. F. Chemical effects in nuclear magnetic resonance and in diamagnetic susceptibility. Phys. Rev. 86, 243 (1952).
11. Saika, A. & Slichter, C.P.A. Note on the fluorine resonance shifts. J. Chem. Phys. 22, 26 (1954).
12. Pople, J. A. The theory of chemical shifts in nuclear magnetic resonance. I. Induced current densities. Proc. R. Soc. London A239, 541 (1957).
13. Pople, J. A. The theory of chemical shifts in nuclear magnetic resonance. II. Interpretation of proton shifts. Proc. R. Soc. London A239, 550 (1957).
14. Ando, I., Nishioka, A. & Asakura, T. The proton chemical shifts and the stereochemical structures of poly(vinyl chloride). Makromol. Chem. 176, 411 (1975).
15. Ando, I., Kato, Y. & Nishioka, A. 13C NMR chemical shifts and stereochemical structures in poly(vinyl chloride). Makromol. Chem. 177, 2759 (1976).
16. Ando, I., Kato, Y., Kondo, M. & Nishioka, A. Solvent effect on the 13C NMR chemical shifts of meso and racemic 2,4-dichloropentanes as the model compounds of poly(vinyl chloride). Makromol. Chem. 178, 803 (1977).
17. Andre, J. M. & Ladik, J. Electronic Structure of Polymer and Molecular Crystals (Plenum Press, New York, 1974).
18. Andre, J. M., Delhalle, J. & Ladik, J. Quantum Theory of Polymers (Reidel, Dordrecht, 1978).
19. Ladik, J. Quantum Theory of Polymers as Solids (Plenum Press, New York, 1988).
20. Sone, M., Yoshimizu, H., Kurosu, H. & Ando, I. Side-chain conformation of poly(Lproline) form II in the crystalline state as studied by high-resolution solid-state 13C NMR spectroscopy. J. Mol. Structure 317, 111 (1994).
21. Kurosu, H., Kikuchi, M. & Ando, I. Structural characterization of polypyrrole in the solid state by high resolution 15N NMR spectroscopy [II]. J. Polym. Sci. Polym. Phys 33, 769 (1995).
22. Yamanobe, T., Chujo, R. & Ando, I. Carbon-13 N.M.R. chemical shift and electronic structure of an infinite polymer chain as studied by tight-binding MO theory Polyethylene, and cis and trans polyacetylenes. Mol. Phys. 50, 1231 (1983).
23. Yamanobe, T. & Ando, I. 13C NMR chemical shift and electronic structure of an infinite polymer chain as studied by tight-binding theory within the CNDO/2 framework: Polyethylene and cis and trans polyacetylenes. J. Chem. Phys. 83, 3154 (1985).
24. Yamanobe, T., Ando, I., Saito , H., Tabeta, R., Shoji, A. & Ozaki, T. Carbon-13 NMR chemical shift and electronic structure of solid polypeptides as studied by tightbinding MO theory. polyglycine and poly(L-alanine). Bull. Chem. Soc. Japan 58, 23 (1985).
25. Yamanobe, T., Ando, I., Saito , H., Tabeta, R., Shoji, A. & Ozaki, T. Carbon-13 NMR chemical shift and electronic structure of polypeptide as studied by tight-binding MO theory: Poly(b-benzyl L-aspartate) with the right-handle a-helix and left-handed a-helix forms. Chem. Phys. 99, 259 (1985).
26. Yamanobe, T., Sorita, T., Komoto, T. & Ando, I. 13C NMR chemical shift and crystal structure of paraffins and polyethylene as studied by solid state NMR. J. Mol. Structure 131, 267 (1985).
27. Yamanobe, T., Ando, I. & Webb, G. A. 13C NMR Chemical shifts and electronic structure of cis and trans polycetylenes as studied by tight-binding theory within the INDO/S framework. J. Mol. Structure, Theochem. 151, 191 (1987).
28. Kurosu, H., Yamanobe, T. & Ando, I. Interchain effect of 13C nuclear magnetic resonance chemical shift and electronic structure of polyoxymethylene chains in the solid state. J. Chem. Phys. 89, 5216 (1988).
29. Ishii, T., Kurosu, H., Yamanobe, T. & Ando, I. Effect of interchain interactions on 13C nuclear magnetic resonance chemical shifts and electronic structures of polyacetylene in the solid state as studied by tight-binding molecular orbital theory. J. Chem. Phys. 89, 7315 (1988).
30. Kurosu, H., Ando, I. & Yamanobe, T. 13C NMR Chemical shift and crystal structure of polyethylene chains in the solid state as studied by tight-binding theory within the INDO/S framework. J. Mol. Structure, Theochem. 201, 239 (1989).
31. Ando, I., Yamanobe, T. & Kurosu, H. N.M.R. Nuclear shielding and the electronic structures of macromolecules. Ann. Rep. NMR Spectrosc. 22, 205 (1990).
32. Uchida, M., Toida, Y., Kurosu, H. & Ando, I. An MO study on 13C NMR chemical shift and the electronic structure of a three-dimensional polymer crystal by ab initio tightbinding MO theory: I. Polyethylene crystal. J. Mol. Structure 508, 181 (1999).
33. Fujii, K., Kuroki, S., Uchida, M., Kurosu, H. & Ando, I. 13C NMR chemical shift and electronic structure of a three-dimensional polyacetylene crystal by ab initio tight binding MO theory. J. Mol. Structure 602/603, 3 (2002).
34. Saito , H., Tabeta, R., Shoji, A., Ozaki, T. & Ando, I. Conformational characterization of polypeptides in the solid state as viewed from the conformation-dependent carbon-13 chemical shifts determined by the carbon-13 cross polarization/magic angle spinning method: Oligo(L-alanine), poly(L-alanine), copolymers of L-and D-alanines, and copolymers of L-alanine with N-methyl-or N-benzyl-L-alanine. Macromolecules 16, 1050 (1983).
35. Saito , H., Tabeta, R., Shoji, A., Ozaki, T., Ando, I. & Asakura, T. in Magnetic Resonance in Biology and Medicine. Govil, G., Khetrapal, C.L. & Saran, A. (eds). (Tata McGraw-Hill, New Dehli, 1985).
36. Saito , H. & Ando, I. High-resolution solid-state NMR studies of synthetic and biological macromolecules. Ann. Rep. NMR Spectrosc. 21, 209 (1989).
37. Ando, I., Yamanobe, T. & Asakura, T. Primary and secondary structures of synthetic polymer systems as studied by 13C NMR spectroscopy. Prog. NMR Spectrosc. 22, 349 (1990).
38. Saito , H. Conformation-dependent 13C chemical shifts: A new means of conformational characterization as obtained by high-resolution solid-state 13C NMR. Magn. Reson. Chem. 24, 835 (1986).
39. Ando, S., Yamanobe, T., Ando, I., Shoji, A., Ozaki, T. & Saito, H. Conformational characterization of glycine residues incorporated into some homopolypeptides by solid-state carbon-13 NMR spectroscopy. J. Am. Chem. Soc. 107, 7648 (1985).
40. Saito , H., Ando, I. & Ramamoorthy, A. Chemical shift tensor -the heart of NMR: Insights into biological aspects of proteins. Prog. NMR Spectrosc. 57, 181 (2010).
41. Saito , H., Tabeta, R., Ando, I., Ozaki, T. & Shoji, A. A high resolution 13C NMR study of solid poly(b-benzyl-L-aspartate) by the cross polarization-magic angle spinning method distinction of the right-handed a-helix, left-handed a-helix, o-helix, and bsheet forms by conformation- dependent 13C chemical shifts. Chem. Letts. 1437 (1983).
42. Saito , H., Tabeta, R., Shoji, A., Ozaki, T., Ando, I. & Miyata, T. A high-resolution 13Cnmr study of collagenlike polypeptides and collagen fibrils in solid state studied by the cross-polarization-magic angle-spinning method. Manifestation of conformationdependent 13C chemical shifts and application to conformational characterization. Biopolymers 23, 2279 (1984).
43. Yoshimizu, H. & Ando, I. Conformational characterization of wool keratin and S-(carboxymethyl)kerateine in the solid state by carbon-13 CP/MAS NMR spectroscopy. Macromolecules 23, 2908 (1990).
44. Yoshimizu, H., Mimura, H. & Ando, I. Carbon-13 CP/MAS NMR study of the conformation of stretched or heated low-sulfur keratin protein films. Macromolecules 24, 862 (1991).
45. Saito , H., Tabeta, R., Asakura, T., Iwanaga, Y., Shoji, A., Ozaki, T. & Ando, I. Highresolution carbon-13 NMR study of silk fibroin in the solid state by the crosspolarization-magic angle spinning method. Conformational characterization of silk I and silk II type forms of Bombyx mori fibroin by the conformation-dependent carbon-13 chemical shifts. Macromolecules 17, 1405 (1984).
46. Yamanobe, T., Tsukahara, M., Komoto, T., Watanabe, J., Ando, I., Uematsu, I., Deguchi, K., Fujito, T. & Imanari, M. Conformation and dynamic aspects of poly(g-noctadecyl L-glutamate) in the solid state and liquid-crystalline state as studied by variable-temperature carbon-13 CP/MAS NMR spectroscopy. Macromolecules 21, 48, (1988).
47. Ando, I. & Yamanobe, T. in Thermotropic Liquid Crystals: Recent Advance. Ramamoorthy, A. (ed.) Chapter 7, p. 176, (Springer, 2007).
48. Zhao, C., Zhang, H., Yamanobe, T., Kuroki, S. & Ando, I. Diffusional behavior of solvent in polypeptide liquid crystalline and gel states with highly oriented chains as studied by NMR spectroscopy. Macromolecules 32, 3389( (1999).
49. Yin, Y., Zhao, C., Kuroki, S. & Ando, I. Diffusional behavior of polypeptides in the thermotropic liquid crystalline state as studied by the pulse field-gradient spin-echo 1H nuclear magnetic resonance method. J. Chem. Phys. 113, 7635 (2000).
50. Murata, K., Kuroki, S. & Ando, I. A study of the conformational stability of poly(Lalanine), poly(D-alanine), poly(L-isoleucine), polyglycine and poly(L-valine) and their polypeptide blends in the solid-state by 13C CP/MAS NMR. Polymer. 43, 6871 (2002).
51. Murata, K., Kono, H., Katoh, E., Kuroki, S. & Ando, I. A study of conformational stability of polypeptide blends by solid state two-dimensional 13C-1H heteronuclear correlation NMR spectroscopy. Polymer 44, 4021 (2003).
52. Saito, H., Ando, I. & Naito, A. Solid State NMR Spectroscopy for Biopolymers (Kluwer Academic Press, London, 2006).
53. Akieda, T., Mimura, H., Kuroki, S., Kurosu, H. & Ando, I. Conformational behavior of poly(b-benzyl L-aspartate) in the solid state as studied by variable-temperature carbon-13 cross-polarization/magic angle spinning nuclear magnetic resonance spectroscopy. Macromolecules 25, 5794 (1992).
54. Okabe, M., Yamanobe, T., Komoto, T., Watanabe, J., Ando, I. & Uematsu, I. Conformational behaviour of poly (b-aspartate) with n-alkyl side chains in the solid state as studied by 13C-CP/MAS-NMR spectroscopy. J. Mol. Structure 213, 213 (1989).
55. Ando, I. Helix change of polypeptides in the solid state as studied by NMR spectroscopy. Macromol. Symp. 101, 371 (1996).
56. Shoji, A., Ozaki, T., Fujito, T., Deguchi, K. & Ando, I. High-resolution nitrogen-15 NMR study of solid homopolypeptides by the cross-polarization-magic angle spinning method: Conformation-dependent nitrogen-15 chemical shifts characteristic of the ahelix and b-sheet forms. Macromolecules 20, 2441 (1987).
57. Shoji, A., Ozaki, T., Fujito, T., Deguchi, K., Ando, S. & Ando, I. Nitrogen-15 NMR chemical shift tensors and conformation of some nitrogen-15-labeled polypeptides in the solid state. Macromolecules 22, 2860 (1989).
58. Shoji, A., Ozaki, T., Fujito, T., Deguchi, K., Ando, S. & Ando, I. Nitrogen-15 chemical shift tensors and conformation of solid polypeptides containing 15N-labeled L-alanine residue by 15N NMR. 2. Secondary structure is reflected in s22. J. Am. Chem. Soc. 112, 4693 (1990).
59. Shoji, A., Ando, S., Kuroki, S., Ando, I. & Webb, G.A. Structural studies of peptides and polypeptides in the solid state by nitrogen-15 NMR. Ann. Rep. NMR Spectrosc. 26, 55 (1993).
60. Kuroki, S., Ando, I., Shoji, A. & Ozaki, T. A structural study of polyglycine II in the solid state by 17O CPMAS NMR spectroscopy. J. Chem. Soc., Chem. Commun. 433 (1992).
61. Kuroki, S., Takahashi, A., Ando, I., Shoji, A. & Ozaki, T. Hydrogen-bonding structural study of solid peptides and polypeptides containing a glycine residue by 17O NMR spectroscopy. J. Mol. Structure 323, 197 (1994).
62. Kuroki, S., Yamauchi, K., Ando, I., Shoji, A. & Ozaki, T. 17O-isotope labeling and hydrogen-bonded structure investigation in peptides and polypeptides by solid state 17O NMR. Curr. Org. Chem. 5, 1001 (2001).
63. Takahashi, A., Kuroki, S., Ando, I., Ozaki, T. & Shoji, A. Hydrogen-bonded structure and NMR parameters of oxygen-17 labeled poly(L-alanine)s as studied by solid state oxygen-17 NMR spectroscopy. J. Mol. Structure 442, 195 (1998).
64. Yamauchi, K., Kuroki, S., Ando, I., Ozaki, T. & Shoji, A. 17O NMR chemical shifts and quadrupole coupling constants in solid poly(L-alanine)s determined using a highspeed MAS technique. Chem. Phys. Letts. 302, 331 (1999).
65. Yamauchi, K., Kuroki, S. & Ando, I. High-resolution solid-state 17O NMR studies of polyglycines and their hydrogen-bonded structures. J. Mol. Structure 602/603, 171 (2002).
66. Kuroki, S., Ando, S. & Ando, I. An MO study of nuclear quadrupolar coupling constant and nuclear shielding of the carbonyl oxygen in solid peptides with hydrogen bonds. Chem. Phys. 195, 107 (1995).
67. Crich, F. H. C. & Rich, A. Structure of polyglycine II. Nature 176, 780 (1955).
68. Amott, S. & Wonacott, A.L. Atomic co-ordinates for an a-helix: Refinement of the crystal structure of a-poly-L-alanine. J. Mol. Biol. 21, 371 (1966).
69. Amott, S., Dover, S. D. & Elliot, A. Structure of b-poly-L-alanine: Refined atomic coordinates for an anti-parallel beta-pleated sheet. J. Mol. Biol. 30, 201 (1967).
70. Lemaitre, V., de Planque, M. R. R., Howes, A. P., Smith, M. E., Dupree, R. & Watts, A. Solid-state 17O NMR as a probe for structural studies of proteins in biomembranes. J. Am. Chem. Soc. 126, 15321 (2004).
71. Shoji, A., Kimura, H., Ozaki, T., Sugisawa, H. & Deguchi, K. Conformational study of solid polypeptides by 1H combined rotation and multiple pulse spectroscopy NMR. J. Am. Chem. Soc. 118, 7604 (1996).
72. Shoji, A., Kimura, H. & Sugisawa, H. Structural studies of amino acids, polypeptides and proteins in the solid state by 1H CRAMPS NMR. Ann. Rep. NMR Spectrosc. 45, 69 (2002).
73. Yamauchi, K., Kuroki, S., Fujii, K. & Ando, I. The amide proton NMR chemical shift and hydrogen-bonded structure of peptides and polypeptides in the solid state as studied by high-frequency solid-state 1H NMR. Chem. Phys. Letts. 324, 435 (2000).
74. Yamauchi, K., Kuroki, S. & Ando, I. The amide proton NMR chemical shift and hydrogen-bonded structure of glycine-containing peptides and polypeptides in the solid state as studied by multi-pulse-associated high-speed MAS 1H NMR. J. Mol. Structure 602/603, 9 (2002).
75. Yamauchi, K., Kuroki, S. & Ando, I. Structural characterization of nylon 4 in the solid state by high-resolution solid-state 1H NMR spectroscopy. Polymer 43, 3331 (2002).
76. Ando, I., Saito , H., Tabeta, R., Shoji, A. & Ozaki, T. Conformation-dependent carbon-13 NMR chemical shifts of poly(L-alanine) in the solid state: FPT INDO calculation of N-acetyl-N0-methyl-L-alanine amide as a model compound of poly(L-alanine). Macromolecules 17, 457 (1984).
77. Asakawa, N., Kurosu, H. & Ando, I. Structural study of peptides containing L-alanine residues by ab initio chemical shielding calculation. J. Mol. Structure 323, 279 (1994).
78. Asakawa, N., Kurosu, H., Ando, I., Shoji, A. & Ozaki, T. A structural study of peptides and proteins containing L-alanine residues by 13C NMR spectroscopy combined with ab initio chemical shift calculations. J. Mol. Structure 317, 119 (1994).
79. Naito, A., Ganapathy, S., Akasaka, K. & McDowell, C. A. Chemical shielding tensor and 13C-14N dipolar splitting in single crystals of L-alanine. J. Chem. Phys. 74, 3190 (1981).
80. de Dios, A. C., Pearson, J. G. & Oldfield, E. Secondary and tertiary structural effects on protein NMR chemical shifts: An ab initio approach. Science 260, 1491 (1993).
81. Spera, S. & Bax, A. Empirical correlation between protein backbone conformation and Ca and Cb 13C nuclear magnetic resonance chemical shifts. J. Am. Chem. Soc. 113, 5490 (1991).
82. Asakura, T., Iwadate, M., Demura, M. & Williamson, M. P. Structural analysis of silk with 13C NMR chemical shift contour plots. Int. J. Biol. Macromol. 24, 167 (1999).
83. Iwadate, M., Asakura, T. & Williamson, M. P. Ca and Cb carbon-13 chemical shifts in proteins from an empirical database. J. Biomol. NMR 13, 199 (1999).
84. Jeffrey, G.A. An Introduction to Hydrogen Bonding (Oxford University Press, New York, 1997).
85. Asakawa, N., Kameda, T., Kuroki, S., Kurosu, H., Ando, S., Ando, I. & Shoji, A. Structural studies of hydrogen-bonded peptides and polypeptides by solid-state NMR. Ann. Rep. NMR Spectrosc. 35, 55 (1998).
86. Ando, I., Kuroki, S., Kurosu, H., Uchida, M. & Yamanobe, T. Modeling NMR chemical shifts in polymers and amorphous matter. ACS Symp. Ser. 732, 24 (1999).
87. Ando, I., Kuroki, S., Kurosu, H. & Yamanobe, T. NMR chemical shift calculations and structural characterizations of polymers. Prog. NMR Spectrosc. 39, 79 (2001).
88. Ando, S., Ando, I., Shoji, A. & Ozaki, T. Intermolecular hydrogen-bonding effect on carbon-13 NMR chemical shifts of glycine residue carbonyl carbons of peptides in the solid state. J. Am. Chem. Soc. 110, 3380 (1988).
89. Asakawa, N., Kuroki, S., Kurosu, H., Ando, I., Shoji, A. & Ozaki, T. Hydrogen-bonding effect on carbon-13 NMR chemical shifts of L-alanine residue carbonyl carbons of peptides in the solid state. J. Am. Chem. Soc. 114, 3261 (1992).
90. Tsuchiya, K., Takahashi, A., Takeda, N., Asakawa, N., Kuroki, S., Ando, I., Shoji, A. & Ozaki, T. Hydrogen-bonding effect on 13C NMR chemical shifts of amino acid residue carbonyl carbons of some peptides in the crystalline state. J. Mol. Structure 350, 233 (1995).
91. Ando, I., Kameda, T., Asakawa, N., Kuroki, S. & Kurosu, H. Structure of peptides and polypeptides in the solid state as elucidated by NMR chemical shift. J. Mol. Structure 441, 213 (1998).
92. Takeda, N., Kuroki, S., Kurosu, H. & Ando, I. 13C-NMR chemical shift tensor and hydrogen-bonded structure of glycine-containing peptides in a single crystal. Biopolymers 50, 61 (1999).
93. Hertzfeld, J. & Berger, E. Sideband intensities in NMR spectra of samples spinning at the magic angle. J. Chem. Phys. 73, 6021 (1980).
94. Gu, Z. & McDermott, A. E. Chemical shielding anisotropy of protonated and deprotonated carboxylates in amino acids. J. Am. Chem. Soc. 115, 4282 (1993).
95. Kameda, T., Takeda, N., Kuroki, S., Ando, S., Ando, I., Shoji, A. & Ozaki, T. Hydrogenbonded structure and 13C NMR chemical shift tensor of amino acid residue carbonyl carbons of peptides and polypeptides in the crystalline state. Part I. J. Mol. Structure 384, 17 (1996).
96. Kuroki, S., Ando, S., Ando, I., Shoji, A., Ozaki, T. & Webb, G. A. Hydrogen-bonding effect on 15N NMR chemical shifts of the glycine residue of oligopeptides in the solid state as studied by high-resolution solid-state NMR spectroscopy. J. Mol. Structure 240, 19 (1990).
97. Kuroki, S., Asakawa, N., Ando, S., Ando, I., Shoji, A. & Ozaki, T. Hydrogen bond length and 15N NMR chemical shift of the glycine residue of some oligopeptides in the solid state. J. Mol. Structure 245, 69 (1991).
98. Hiyama, Y., Niu, C. H., Silverton, J. V., Bavoso, A. & Torcha, D. A. Determination of 15N chemical shift tensor via 15N-2H dipolar coupling in Boc-glycylglycyl[15N glycine]benzyl ester. J. Am. Chem. Soc. 110, 2378 (1988).
99. Kuroki, S., Yamauchi, K., Kurosu, H., Ando, S., Ando, I., Shoji, A. & Ozaki, T. 17O NMR Chemical Shifts in Peptides. ACS Symp. Ser. 732, 126 (1999).
100. Astbury, W. T., Dalgleish, C. H., Darmon, S. E. & Sutherland, G. B. B. M. Studies of the structure of synthetic polypeptides. Nature 69, 596 (1948).
101. McDermott, A. E. & Ridenour, C. F. in Encyclopedia of NMR. Grant, D. M. & Harris, R. K. (eds). (John Wiley & Sons, New York, 1996).
102. Wei, Y. & McDermott, A. E. Effects of hydrogen bonding on 1H chemical shifts. ACS Symp. Ser. 732, 177 (1999).
103. Bielecki, A., Kolbert, A. C. & Levitt, M. H. Frequency-switched pulse sequences: Homonuclear decoupling and dilute spin NMR in solids. Chem. Phys. Letts 155, 341 (1989).
104. Levitt, M. H., Kolbert, A. C., Bielecki, A. & Ruben, D. J. High-resolution 1H NMR in solids with frequency-switched multiple-pulse sequences. Solid State NMR 2, 151 (1993).
105. Hafner, S. & Spiess, H. W. Multiple-pulse line narrowing under fast magic-angle spinning. J. Magn. Reson. A 121, 160 (1996).
106. Hafner, S. & Spiess, H. W. Multiple-pulse assisted line-narrowing by fast magic-angle spinning. Solid State NMR 8, 17 (1997).
107. Hori, S., Yamauchi, K., Kuroki, S. & Ando, I. Proton NMR chemical shift behavior of hydrogen-bonded amide proton of glycine-containing peptides and polypeptides as studied by ab initio MO calculation. Int. J. Mol. Sci. 3, 907 (2002).
108. Kimura, H., Shoji, A., Sugisawa, H., Deguchi, K., Naito, A. & Saito , H. Determination of N-H bond lengths of 15N-labeled poly(l-alanines) by 1H CRAMPS NMR. Macromolecules 33, 6627 (2000).