Resonance Raman Examination of the Electronic Excited States of Glycylglycine and Other Dipeptides:  Observation of a Carboxylate→Amide Charge Transfer Transition

Chen, X. G.; Li, Pusheng; Holtz, J.; Chi, Zhenhuan; Pajcini, Vasil; Asher, Sanford A.; Kelly, Lisa A.

doi:10.1021/ja960421+

Cited by 62 publications

(111 citation statements)

References 55 publications

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“…Such a small change of J rules out the possibility that the backbone conformation changes with respect to pH. It is believed that such a strong pH dependency of trialanine CD spectrum is likely related to the charge transfer transitions 41,[64][65][66][67] between the C-terminal carboxylate group and the neighboring peptide group as discussed by Dragomir et al 41 , where they examined the far-UV absorption and electronic CD spectra of Ala-X and X-Ala (where X represents different amino acid residues) and considered the difference spectra obtained by subtracting the spectrum of the cationic species from that of the corresponding zwitterionic one. In Figure 4a inset, the difference CD spectrum of trialanine obtained by subtracting the pH 2 spectrum from the pH 7 spectrum at 208C is plotted.…”

Section: Temperature and Ph Dependencies Of Nà àH Proton Chemical Shimentioning

confidence: 99%

Circular dichroism eigenspectra of polyproline II and β‐strand conformers of trialanine in water: Singular value decomposition analysis

Lee

Park

et al. 2010

Chirality

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Despite that a number of experimental and theoretical investigations have been carried out to determine the structure of trialanine in water, the reported populations of polyproline II (PPII) and β-strand conformers vary and were found to be dependent on which spectroscopic method was used. Such discrepancies are due to limitations of different spectroscopic methods used. Here, the temperature- and pH-dependent circular dichroism (CD) and NMR experiments have been carried out to develop a self-consistent singular value decomposition procedure. The temperature-dependent CD spectra indicate the presence of two conformers, but due to the two peptide bonds in a trialanine, one should take into consideration of four different conformers to fully interpret the NMR results. From the pH-dependent NMR coupling constant measurements, the conformation of zwitterionic trialanine is little different from that of cationic one. The strong pH dependency of CD spectrum is likely due to charge transfer transitions between carboxylate and nearby peptide groups or internal field effects not to pH-dependent conformational change. To simultaneously analyze the temperature-dependent CD and NMR data, a self-consistent procedure was used to newly determine the reference NMR coupling constants required to estimate one of the peptide dihedral angles. From the estimated enthalpy and entropy changes associated with the transition from enthalpically favorable PPII conformer to entropically favorable β-strand conformer, the relative populations of the four possible conformers of trialanine were determined and compared with the previous experimental findings. We anticipate that the present experimental results and interpretation procedure would be of use in determining the solution structures of small oligopeptides in the future.

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Section: Temperature and Ph Dependencies Of Nà àH Proton Chemical Shimentioning

confidence: 99%

Circular dichroism eigenspectra of polyproline II and β‐strand conformers of trialanine in water: Singular value decomposition analysis

Lee

Park

et al. 2010

Chirality

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“…Chen et al 97 measured the UVRR spectra of several isotopic derivatives of acetylglycine and found that most of the 1400 cm 1 band intensity arises from the COO ss. It is overlaid by another band assignable to CH 2 wagging (w).…”

Section: Uvrr Of Di-and Tripeptidesmentioning

confidence: 99%

Visible and UV‐resonance Raman spectroscopy of model peptides

Schweitzer‐Stenner

2001

J Raman Spectroscopy

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We review various visible and UV-resonance Raman experiments on model peptides such as N-methylacetamide and di-and triglycine which are aimed at exploring the structure and dynamics of these molecules. Whereas visible Raman spectroscopy probes the electronic ground state, the UV Raman technique is utilized additionally to obtain structural information about excited electronic states. This research is aimed at obtaining a spectroscopically determined force field, which can be transferred to polypeptides and proteins. We further argue that the capability of vibrational spectroscopy to probe the structure of peptides and proteins can be significantly improved by combining computational and spectroscopic studies on appropriate model peptides to calibrate wavenumbers and intensities of Raman and IR bands for the quantitative determination of structural parameters such as the dihedral angles.

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“…28 In the same frequency region, the CO 2 symmetric stretch, which exhibits a downshift of 14 cm 1 upon 13 CO 2 substitution, was also resonance enhanced at 1396 cm 1 , when the CO 2 group yields charge transfer (CT) interactions with the amide group. 29 On the other hand, there is an argument that the 1495 cm 1 band is an amide II band of cis peptide linkages, since the band is observed upon the increase of laser power. 30,31 The trans -NHDCO-bond is thought to undergo photoisomerization into cis -NHDCO-upon UV irradiation.…”

Section: Amide Modesmentioning

confidence: 99%

Raman Spectroscopy of Proteins

Kitagawa¹,

Hirota²

2001

Handbook of Vibrational Spectroscopy

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The sections in this article are Introduction General Aspects of Ordinary R aman Spectra of Proteins Amides I and III Frequencies and Secondary Structures T rp Bands and Microenvironments of T rp Residues T yr Bands and Hydrogen Bonding Histidine Band and Protonation S  S Stretching Frequency and Conformation of Disulfide Bridge UV Resonance R aman Spectra of Proteins Amide Modes Tyrosine‐Related Modes Tryptophan‐Related Modes Histidine‐Related Modes Cysteine‐Related Modes X ‐Proline Vibrational Modes Modes of Metal‐Coordinated Residues Visible Resonance R aman Spectra of Proteins Heme Proteins Heme Skeletal Vibrational Modes Fe  H is and Fe  C ys stretching modes Fe ( II )‐ O 2 Related Modes Fe ( II )‐ CO Related Modes Fe ( III )‐ CN Related Modes Fe ( II )‐ NO and Fe ( III )‐ NO Related Modes Fe ( III )‐ OH Related Modes Fe ( IV ) O Related Modes Copper Proteins Quinone Vibrations of Quinoproteins Tyrosine Radical Modes in Proteins Flavo Proteins Vis RR Spectra of Other Proteins

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Resonance Raman Examination of the Electronic Excited States of Glycylglycine and Other Dipeptides: Observation of a Carboxylate→Amide Charge Transfer Transition

Cited by 62 publications

References 55 publications

Circular dichroism eigenspectra of polyproline II and β‐strand conformers of trialanine in water: Singular value decomposition analysis

Circular dichroism eigenspectra of polyproline II and β‐strand conformers of trialanine in water: Singular value decomposition analysis

Visible and UV‐resonance Raman spectroscopy of model peptides

Raman Spectroscopy of Proteins

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