Vibrational Analysis of Amino Acids and Short Peptides in Hydrated Media. VIII. Amino Acids with Aromatic Side Chains: L-Phenylalanine, L-Tyrosine, and L-Tryptophan

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Hernandez, B., Pflueger, F., Adenier, A., Kruglik, S.-G., & Ghomi, M. (2010). Vibrational Analysis of Amino Acids and Short Peptides in Hydrated Media. VIII. Amino Acids with Aromatic Side Chains: L-Phenylalanine, L-Tyrosine, and L-Tryptophan. Journal of Physical Chemistry B, 114(46), 15319-15330. https://doi.org/10.1021/jp106786j

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@article{Hernandez2010_37,
  author = {Hernandez, Belen and Pflueger, Fernando and Adenier, Alain and Kruglik, Sergei G. and Ghomi, Mahmoud},
  year = {2010},
  month = {11},
  title = {Vibrational Analysis of Amino Acids and Short Peptides in Hydrated Media. VIII. Amino Acids with Aromatic Side Chains: L-Phenylalanine, L-Tyrosine, and L-Tryptophan},
  journal = {Journal of Physical Chemistry B},
  publisher = {AMER CHEMICAL SOC},
  volume = {114},
  number = {46},
  pages = {15319-15330},
  address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA},
  abstract = {Four out of the 20 natural alpha-amino acids (alpha-AAs) contain aromatic rings in their side chains. In a recent paper (J. Phys. Chem. B 2010, 114, 9072-9083), we have analyzed the structural and vibrational features of L-histidine, one of the potent elements of this series. Here, we report on the three remaining members of this family, i.e., L-phenylalanine, L-tyrosine, and L-tryptophan. Their solution (H(2)O and D(2)O) Raman scattering and Fourier transform infrared absorption attenuated total reflection (FT-IR ATR) spectra were measured at room temperature from the species corresponding to those existing at physiological conditions. Because of the very low water solubility of tyrosine, special attention was paid to avoid any artifact concerning the report of the vibrational spectra corresponding to nondissolved powder of this AA in aqueous solution. Finally, we could obtain for the first time the Raman and FT-IR spectra of tyrosine at very low concentration (2.3 mM) upon long accumulation time. To clarify this point, those vibrational spectra of tyrosine recorded either in the solid phase or in a heterogeneous state, where dissolved and nondissolved species of this AA coexist in aqueous solution, are also provided as Supporting Information. To carry out a discussion on the general geometrical and vibrational behavior of these AAs, we resorted to quantum mechanical calculations at the DFT/B3LYP/6-31++FG\{*\} level, allowing (i) determination of potential energy surfaces of these AAs in a continuum solvent as a function of the torsion angles chi(1) and chi(2), defining the conformation of each aromatic side chain around C(alpha)-C(beta) and C(beta)-C(gamma) bonds, respectively; (ii) analysis of geometrical features of the AAs surrounded by clusters of n explicit (n = 5-7) water molecules interacting with the backbone and aromatic rings; and (iii) assignment of the observed vibrational modes by means of the theoretical data provided by the lowest energy conformers of explicitly hydrated amino acids.},
  url = {http://www.dx.doi.org/10.1021/jp106786j},
  doi = {10.1021/jp106786j},
  issn = {1520-6106},
}

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TY  - JOUR
AU  - Hernandez, Belen
AU  - Pflueger, Fernando
AU  - Adenier, Alain
AU  - Kruglik, Sergei G.
AU  - Ghomi, Mahmoud
PY  - 2010
DA  - 2010/11/25
TI  - Vibrational Analysis of Amino Acids and Short Peptides in Hydrated Media. VIII. Amino Acids with Aromatic Side Chains: L-Phenylalanine, L-Tyrosine, and L-Tryptophan
JO  - Journal of Physical Chemistry B
VL  - 114
IS  - 46
PB  - AMER CHEMICAL SOC
SN  - 1520-6106
AB  - Four out of the 20 natural alpha-amino acids (alpha-AAs) contain aromatic rings in their side chains. In a recent paper (J. Phys. Chem. B 2010, 114, 9072-9083), we have analyzed the structural and vibrational features of L-histidine, one of the potent elements of this series. Here, we report on the three remaining members of this family, i.e., L-phenylalanine, L-tyrosine, and L-tryptophan. Their solution (H(2)O and D(2)O) Raman scattering and Fourier transform infrared absorption attenuated total reflection (FT-IR ATR) spectra were measured at room temperature from the species corresponding to those existing at physiological conditions. Because of the very low water solubility of tyrosine, special attention was paid to avoid any artifact concerning the report of the vibrational spectra corresponding to nondissolved powder of this AA in aqueous solution. Finally, we could obtain for the first time the Raman and FT-IR spectra of tyrosine at very low concentration (2.3 mM) upon long accumulation time. To clarify this point, those vibrational spectra of tyrosine recorded either in the solid phase or in a heterogeneous state, where dissolved and nondissolved species of this AA coexist in aqueous solution, are also provided as Supporting Information. To carry out a discussion on the general geometrical and vibrational behavior of these AAs, we resorted to quantum mechanical calculations at the DFT/B3LYP/6-31++FG{*} level, allowing (i) determination of potential energy surfaces of these AAs in a continuum solvent as a function of the torsion angles chi(1) and chi(2), defining the conformation of each aromatic side chain around C(alpha)-C(beta) and C(beta)-C(gamma) bonds, respectively; (ii) analysis of geometrical features of the AAs surrounded by clusters of n explicit (n = 5-7) water molecules interacting with the backbone and aromatic rings; and (iii) assignment of the observed vibrational modes by means of the theoretical data provided by the lowest energy conformers of explicitly hydrated amino acids.
SP  - 15319
EP  - 15330
DO  - 10.1021/jp106786j
UR  - http://www.dx.doi.org/10.1021/jp106786j
ER  -