Resonance Raman spectra of poly(<scp>L</scp>‐lysine), aromatic amino acids, <scp>L</scp>‐histidine and native and thermally unfolded ribonuclease A

Chinsky, L.; Jollès, Béatrice; Laigle, Alain; Turpin, Pierre‐Yves

doi:10.1002/jrs.1250160404

Cited by 22 publications

(12 citation statements)

References 21 publications

(4 reference statements)

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“…Raman and IR spectroscopies have been used to investigate the histidine structures in proteins as well as in model compounds. ,,− These vibrational spectroscopies are especially useful for identifying the coordination and protonation state of histidine because certain ring modes are highly sensitive to the difference in structural forms. Additionally, the metal−imidazole and N−H vibrations can be directly detected.…”

Section: Introductionmentioning

confidence: 99%

Ab Initio Density Functional Theory Calculations and Vibrational Analysis of Zinc-Bound 4-Methylimidazole as a Model of a Histidine Ligand in Metalloenzymes

2001

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Histidine is often found as a ligand in metalloenzymes. The imidazole side group has two nitrogen atoms capable of being protonated or of participating in metal binding. Hence, histidine can take on various metal-bound and protonated forms in proteins. Because of its variable structural state, histidine often functions as a key amino acid residue in enzymatic reactions. Raman and IR spectroscopies have been used as powerful methods to investigate the structure of histidine in proteins. In an attempt to establish the Raman and IR markers reflecting the coordinated and protonated states of histidine, we have calculated the optimized geometry and vibrational frequencies of various forms of zinc(II) complexes of 4-methylimidazole (4-MeIm), as a model of a histidine ligand, using the density functional theory (DFT) method. The effects of metal binding on the frequency and N-deuteration shift of the C4C5 stretching mode around 1600 cm-1 and of the C5N1 stretch around 1100 cm-1 were satisfactorily reproduced in calculation and explained by changes in the bond distances and the mixing of vibrations. Additionally, the calculated frequency of the Zn−imidazole stretching mode of neutral 4-MeIm at 260−255 cm-1 exhibited an upshift by ∼25 cm-1 upon its deprotonation, being consistent with the experimental observation. Furthermore, assignments were done for the several ring vibrations in the 1510−1250 cm-1 region that have previously been used as Raman markers of the metal-bound forms. The results provided a theoretical basis for use of these markers as a basis for determining the structure of histidine in proteins. Atomic charge calculations by the natural population analysis revealed that deprotonation of the MeIm ligand decreased the charge of the Zn2+ ion and decreased the acidity of the water ligands. This suggests a possible role of the histidine ligand in controlling the catalytic reactions of metalloenzymes by changing its protonation state.

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Section: Introductionmentioning

confidence: 99%

Ab Initio Density Functional Theory Calculations and Vibrational Analysis of Zinc-Bound 4-Methylimidazole as a Model of a Histidine Ligand in Metalloenzymes

2001

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“…Recently, UV resonance Raman (UVRR) spectroscopy has been shown to be a powerful technique for elucidating the structure of proteins (Johnson et al, 1984;Chinsky et al, 1985; Rava & Spiro, 1984,1985a, 1987; Asher et al, 1986;Hudson & Mayne, 1984). Selective enhancement of the Raman bands of the amide bond and of the aromatic amino acid residues is possible with appropriate choice of excitation wavelength.…”

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confidence: 99%

Tyrosine hydrogen-bonding and environmental effects in proteins probed by ultraviolet resonance Raman spectroscopy

et al. 1988

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Ultraviolet resonance Raman spectra with 229-nm excitation are reported for aqueous tyrosine and for ovomucoid third domain proteins from chicken [OMCHI3(-)] and from chachalaca [OMCHA(-)], as well as alpha 1-, alpha 2-, and beta-purothionin. At this excitation wavelength interference from phenylalanine is minimized, and it is possible to determine the frequencies of the Tyr ring modes nu 8a and nu 8b. The nu 8b frequency decreases with the degree of Tyr H-bond donation, reaching a limiting value for deprotonated tyrosine. This spectroscopic indicator of H-bond strength was calibrated by using the model compound p-cresol in H-bond acceptor solutions for which the enthalpy of H-bond formation can be obtained from the literature. With this calibration it is possible to estimate Tyr H-bond enthalpies in proteins for which Tyr is a H-bond donor; values of 13.7, 9.6, and 11.2 kcal/mol were found for OMCHA3(-) and for alpha 1- (or alpha 2-) and beta-purothionin, respectively. The intensity of the 1176-cm-1 nu 9a band of Tyr excited at 229 nm and also the intensity ratio of the Tyr 830/850-cm-1 Fermi doublet excited at 200 nm both correlate strongly with the estimated H-bond enthalpies, but large deviations are seen for the purothionins, reflecting a special environment for the Tyr residue of these proteins, which is believed to be constrained in a hydrophobic pocket. The molar intensity of the strong approximately 1000-cm-1 nu 12 band of phenylalanine in aqueous solution is about half the value observed in most proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…Far-UV absorption spectroscopy, however, is not a convenient method for the determination of protein secondary structure because of interferences from the overlapping absorptions of the aromatic amino acids and other protein components (Wetlaufer, 1962). Recently, several groups have turned their attention to UV resonance Raman (UVRR) spectroscopy as a means of studying structure in model amides and proteins (Chinsky et al, 1985;Dudik et al, 1985a;Johnson et al, 1984;Mayne et al, 1985;Rava & Spiro, 1985). Due to the resonance enhancement, UVRR spectroscopy is applicable at far lower concentrations than visible excitation Raman spectroscopy (although the amounts of material required are similar because of the need to circulate the UVRR sample to avoid thermal and photoinduced damage), and nonprotein components of the sample (e.g., lipids, buffers) do not interfere.…”

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confidence: 99%

Secondary structure determination in proteins from deep (192-223-nm) ultraviolet Raman spectroscopy

Copeland¹,

Spiro²

1987

Biochemistry

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Raman intensities obtained with UV laser excitation at 223, 218, 204, 200, and 192 nm are reported for the amide I, II, III, and II' bands of random-coil polylysine. The excitation profiles show enhancement via the pi-pi electronic transition, at approximately 190 nm. Enhancement for amide I is weak, however, and most of the intensity can be accounted for by preresonance with a deeper UV transition at approximately 165 nm. The amide II' band dominates the spectrum in D2O, consistent with the suggestion that the main distortion coordinate in the pi-pi excited state is the stretching of the C-N peptide bond. Amide II intensities with 200- and 192-nm excitation are reported for several proteins. The previously reported negative linear correlation with alpha-helix content (due to Raman hypochromism in the alpha-helices) is found not to apply to proteins with high beta-sheet content when the excitation wavelength is 200 nm. Much higher intensities are seen for these proteins and are attributed to a red shift of the pi-pi absorption for the beta-structure. A linear correlation with alpha-helix content is found for excitation of 192 nm, which corresponds to an isosbestic point of the beta-sheet and random-coil absorption bands. Characteristic amide II Raman cross sections are derived for alpha-helical, beta-sheet, and random-coil elements and are used to determine secondary structure for alpha 1- and beta-purothionin, by use of amide II intensities with 200- and 192-nm excitation. The results are in good agreement with a previous determination based on amide I band deconvolution in off-resonance Raman spectra.

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Resonance Raman spectra of poly(L‐lysine), aromatic amino acids, L‐histidine and native and thermally unfolded ribonuclease A

Cited by 22 publications

References 21 publications

Ab Initio Density Functional Theory Calculations and Vibrational Analysis of Zinc-Bound 4-Methylimidazole as a Model of a Histidine Ligand in Metalloenzymes

Ab Initio Density Functional Theory Calculations and Vibrational Analysis of Zinc-Bound 4-Methylimidazole as a Model of a Histidine Ligand in Metalloenzymes

Tyrosine hydrogen-bonding and environmental effects in proteins probed by ultraviolet resonance Raman spectroscopy

Secondary structure determination in proteins from deep (192-223-nm) ultraviolet Raman spectroscopy

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