Imidazole Trimer-Water Complexes in Superfluid Helium Nanodroplets: Water Stretching Modes

Ahn, Ahreum; Lee, Seungjun; Lee, Seulki; Min, Ahreum; Kim, Yu-Sic; Jung, Hyeon-Jin; Sehee, Hong; Lee, Joon‐Hwa; Choi, Myong-Yong; Miller, R. E.

doi:10.5012/bkcs.2011.32.4.1407

Cited by 3 publications

(1 citation statement)

References 21 publications

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“…In conflict with this proposed cyclic structure, the trimer spectrum in helium droplets displays a free NH stretch. This has been explained by a non-cyclic, chain-like structure 18 which persists in the hydrate, 19 in agreement with an earlier B3LYP prediction, 20 at the time without London dispersion corrections. 21 The previous B3LYP prediction of a cyclic structure 17 was not discussed, but it was mentioned that the chain-like structure may be kinetically controlled.…”

Section: Introductionsupporting

confidence: 83%

Strained hydrogen bonding in imidazole trimer: a combined infrared, Raman, and theory study

Forsting

Zischang

Suhm

et al. 2019

Phys. Chem. Chem. Phys.

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Section: Introductionsupporting

confidence: 83%

Strained hydrogen bonding in imidazole trimer: a combined infrared, Raman, and theory study

Forsting

Zischang

Suhm

et al. 2019

Phys. Chem. Chem. Phys.

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NMR Studies of Active‐Site Properties of Human Carbonic Anhydrase II by Using ¹⁵N‐Labeled 4‐Methylimidazole as a Local Probe and Histidine Hydrogen‐Bond Correlations

Shenderovich

Lesnichin

et al. 2014

Chemistry A European J

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By using a combination of liquid and solid-state NMR spectroscopy, (15) N-labeled 4-methylimidazole (4-MI) as a local probe of the environment has been studied: 1) in the polar, wet Freon CDF3 /CDF2 Cl down to 130 K, 2) in water at pH 12, and 3) in solid samples of the mutant H64A of human carbonic anhydrase II (HCA II). In the latter, the active-site His64 residue is replaced by alanine; the catalytic activity is, however, rescued by the presence of 4-MI. For the Freon solution, it is demonstrated that addition of water molecules not only catalyzes proton tautomerism but also lifts its quasidegeneracy. The possible hydrogen-bond clusters formed and the mechanism of the tautomerism are discussed. Information about the imidazole hydrogen-bond geometries is obtained by establishing a correlation between published (1) H and (15) N chemical shifts of the imidazole rings of histidines in proteins. This correlation is useful to distinguish histidines embedded in the interior of proteins and those at the surface, embedded in water. Moreover, evidence is obtained that the hydrogen-bond geometries of His64 in the active site of HCA II and of 4-MI in H64A HCA II are similar. Finally, the degeneracy of the rapid tautomerism of the neutral imidazole ring His64 reported by Shimahara et al. (J. Biol. Chem.- 2007, 282, 9646) can be explained with a wet, polar, nonaqueous active-site conformation in the inward conformation, similar to the properties of 4-MI in the Freon solution. The biological implications for the enzyme mechanism are discussed.

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Geometry of an Isolated Dimer of Imidazole Characterised by Rotational Spectroscopy and Ab Initio Calculations

et al. 2016

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An isolated, gas-phase dimer of imidazole is generated through laser vaporisation of a solid rod containing a 1:1 mixture of imidazole and copper in the presence of an argon buffer gas undergoing supersonic expansion. The complex is characterised through broadband rotational spectroscopy and is shown to have a twisted, hydrogen-bonded geometry. Calculations at the CCSD(T)(F12*)/cc-pVDZ-F12 level of theory confirm this to be the lowest-energy conformer of the imidazole dimer. The distance between the respective centres of mass of the imidazole monomer subunits is determined to be 5.2751(1) Å, and the twist angle γ describing rotation of one monomer with respect to the other about a line connecting the centres of mass of the monomers is determined to be 87.9(4)°. Four out of six intermolecular parameters in the model geometry are precisely determined from the experimental rotational constants and are consistent with results calculated ab initio.

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Imidazole Trimer-Water Complexes in Superfluid Helium Nanodroplets: Water Stretching Modes

Cited by 3 publications

References 21 publications

Strained hydrogen bonding in imidazole trimer: a combined infrared, Raman, and theory study

Strained hydrogen bonding in imidazole trimer: a combined infrared, Raman, and theory study

NMR Studies of Active‐Site Properties of Human Carbonic Anhydrase II by Using ¹⁵N‐Labeled 4‐Methylimidazole as a Local Probe and Histidine Hydrogen‐Bond Correlations

Geometry of an Isolated Dimer of Imidazole Characterised by Rotational Spectroscopy and Ab Initio Calculations

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Imidazole Trimer-Water Complexes in Superfluid Helium Nanodroplets: Water Stretching Modes

Cited by 3 publications

References 21 publications

Strained hydrogen bonding in imidazole trimer: a combined infrared, Raman, and theory study

Strained hydrogen bonding in imidazole trimer: a combined infrared, Raman, and theory study

NMR Studies of Active‐Site Properties of Human Carbonic Anhydrase II by Using 15N‐Labeled 4‐Methylimidazole as a Local Probe and Histidine Hydrogen‐Bond Correlations

Geometry of an Isolated Dimer of Imidazole Characterised by Rotational Spectroscopy and Ab Initio Calculations

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NMR Studies of Active‐Site Properties of Human Carbonic Anhydrase II by Using ¹⁵N‐Labeled 4‐Methylimidazole as a Local Probe and Histidine Hydrogen‐Bond Correlations