scholarly journals The role of secondary interactions on the preferred conformers of the fenchone–ethanol complex

2019 ◽  
Vol 21 (6) ◽  
pp. 2938-2945 ◽  
Author(s):  
Donatella Loru ◽  
Isabel Peña ◽  
M. Eugenia Sanz
Keyword(s):  
Hydrogen Bond ◽  
High Resolution ◽  
Weak Interactions ◽  
Side Chain ◽  
Rotational Spectroscopy ◽  
Secondary Interactions ◽  
Relative Arrangement

Three conformers of the complex formed between fenchone, a natural common odorant, and ethanol, a mimic of serine's side chain, have been identified using high resolution rotational spectroscopy. All conformers show a main O⋯H–O hydrogen bond and C–H⋯O secondary weak interactions, which drive the relative arrangement of the two moieties.

scholarly journals Fourier transform microwave spectroscopy of Ac-Ser-NH2: the role of side chain interactions in peptide folding

2015 ◽  
Vol 17 (31) ◽  
pp. 20274-20280 ◽  
Author(s):  
Carlos Cabezas ◽  
Martinus A. T. Robben ◽  
Anouk M. Rijs ◽  
Isabel Peña ◽  
J. L. Alonso
Keyword(s):  
Fourier Transform ◽  
Microwave Spectroscopy ◽  
Peptide Folding ◽  
Side Chain ◽  
Rotational Spectroscopy ◽  
Fourier Transform Microwave Spectroscopy

Dipeptide Ac-Ser-NH2 has been investigated using rotational spectroscopy with the polar side chain of serine, which is shown to be at the origin of the conformational locking to a γ-turn species.

scholarly journals The role of nitro groups in the binding of nitroaromatics to protein MOPC 315

1978 ◽  
Vol 173 (3) ◽  
pp. 713-722 ◽  
Author(s):  
P Gettins ◽  
D Givol ◽  
R A Dwek
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
High Resolution ◽  
Hydrogen Bonds ◽  
Fluorescence Quenching ◽  
Nitro Group ◽  
Protein Interactions ◽  
Chemical Shifts ◽  
Binding Constants

Two series of dinitrophenyl haptens, in which chlorine replaces one or both nitro groups, were used to investigate, by a combination of high-resolution 1H n.m.r. and fluorescence quenching, the presence of groups in the combining site of protein MOPC 315, which form hydrogen bonds to the aromatic-ring substituents of the hapten. The large differences in binding constants on successive replacement of nitro groups were shown to be due to specific hapten-substituent-protein interactions by (a) showing that there was little difference in the interaction between these haptens and 3-methylindole (a model for the residue tryptophan-93L with which the hapten stacks in protein MOPC 315), (b) proving by 1H n.m.r. that the mode of hapten binding is constant and (c) showing that the differences in Kd were consistent with the relative hydrogen-bonding capacities of chlorine and the nitro moiety. In this way it was established that each nitro group forms a hydrogen bond. Furthermore, from consideration of the 1H n.m.r. chemical shifts of several dinitrophenyl haptens and their trinitrophenyl analogues, it was shown that there is no distortion of the o-nitro group on binding to the variable fragment of protein MOPC 315.

Water bridges anchored by a C–H⋯O hydrogen bond: the role of weak interactions in molecular solvation

2016 ◽  
Vol 18 (40) ◽  
pp. 27745-27749 ◽  
Author(s):  
Aditi Bhattacherjee ◽  
Sanjay Wategaonkar
Keyword(s):  
Hydrogen Bond ◽  
Ab Initio ◽  
Infrared Spectra ◽  
Direct Evidence ◽  
Weak Interactions ◽  
Imidazole Ring ◽  
Water Bridges ◽  
Hydrogen Bonded

Hydrogen-bonded water bridges are re-directed from a polar NH bond to a weakly activated C(2)–H bond upon N-methylation. Infrared spectra, supported by ab initio calculations, provide direct evidence of the role of the C(2)–H donor in the solvation of the imidazole ring.

scholarly journals Rotational Spectroscopy Meets Quantum Chemistry for Analyzing Substituent Effects on Non-Covalent Interactions: The Case of the Trifluoroacetophenone-Water Complex

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4899
Author(s):  
Juncheng Lei ◽  
Silvia Alessandrini ◽  
Junhua Chen ◽  
Yang Zheng ◽  
Lorenzo Spada ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Substituent Effects ◽  
Equilibrium Structure ◽  
Proton Donor ◽  
Rotational Spectroscopy ◽  
Donor And Acceptor ◽  
Analogous Complex ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The most stable isomer of the 1:1 complex formed by 2,2,2-trifluoroacetophenone and water has been characterized by combining rotational spectroscopy in supersonic expansion and state-of-the-art quantum-chemical computations. In the observed isomer, water plays the double role of proton donor and acceptor, thus forming a seven-membered ring with 2,2,2-trifluoroacetophenone. Accurate intermolecular parameters featuring one classical O-H···O hydrogen bond and one weak C-H···O hydrogen bond have been determined by means of a semi-experimental approach for equilibrium structure. Furthermore, insights on the nature of the established non-covalent interactions have been unveiled by means of different bond analyses. The comparison with the analogous complex formed by acetophenone with water points out the remarkable role played by fluorine atoms in tuning non-covalent interactions.

Conformational Study of Catecholamines in Solution

1983 ◽  
Vol 38 (9-10) ◽  
pp. 758-762 ◽  
Author(s):  
P. Šolmajer
Keyword(s):  
High Resolution ◽  
Aqueous Solutions ◽  
Mole Fraction ◽  
Receptor Site ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Conformational Study ◽  
Pmr Spectroscopy ◽  
Opposite Trend

Abstract Conformations of noradrenaline, dopamine and ephedrine have been studied in aqueous solutions using high resolution PMR spectroscopy. We found that for dopamine the mole fraction of trans rotamer is increased if pH is changed from acidic to basic while for nor­adrenaline and ephedrine the opposite trend is observed: gauche rotamer forms of the side chain become more populated. These changes are discussed in relation to the role of the benzylic hydroxyl group for conformation and/or binding to a receptor site in the biophase.

Phase Transitions in the Crystals ofl- anddl-Cysteine on Cooling: The Role of the Hydrogen-Bond Distortions and the Side-Chain Motions. 2.dl-Cysteine

2009 ◽  
Vol 113 (15) ◽  
pp. 5262-5272 ◽  
Author(s):  
Vasil S. Minkov ◽  
Nikolay A. Tumanov ◽  
Boris A. Kolesov ◽  
Elena V. Boldyreva ◽  
Sergei N. Bizyaev
Keyword(s):  
Hydrogen Bond ◽  
Phase Transitions ◽  
Side Chain

scholarly journals Noncovalent Complexes of an Inactive Mutant of CTX-M-9 with the Substrate Piperacillin and the Corresponding Product

2011 ◽  
Vol 55 (12) ◽  
pp. 5660-5665 ◽  
Author(s):  
David Leyssene ◽  
Julien Delmas ◽  
Frédéric Robin ◽  
Antony Cougnoux ◽  
Lucie Gibold ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Catalytic Process ◽  
Side Chain ◽  
Noncovalent Complexes

ABSTRACTWe determined the crystal structure of an inactive Ser70Gly mutant of CTX-M-9 in complex with the bulky penicillin piperacillin at precovalent and posthydrolytic stages in the catalytic process. The structures obtained at high resolution were compared with the corresponding structures for the small penicillin benzylpenicillin and the bulky cephalosporin cefotaxime. The findings highlight the key role of the configuration of the carbon adjacent to the acylamino group of the side chain of β-lactams in the precovalent recognition of substrates.

Sign in / Sign up

Export Citation Format

Share Document