On the influence of secondary structure on the alpha-C--H bond dissociation energy of proline residues in proteins: a theoretical study
Article Abstract:
A theoretical study has been made of the influence of secondary structure on the alpha-C--H bond dissociation energy of proline residues in proteins. Ab initio computations have been used to predict alpha-C--H bond dissociation energies (BDEs) for proline residue in a model peptide. The model was intended to mimic protein environment, further constrained to mimic common proline positions in beta turns of different types. Computations involved B3LYP/6-31G(D), coupled with isodesmic reactions. Predicted BDEs for the proline alpha C--H bond, in kJ(1/mol) are fully optimized trans rotamer, 368.6; beta turn type II, 397.8; and others.
Publication Name: Canadian Journal of Chemistry
Subject: Chemistry
ISSN: 0008-4042
Year: 1998
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Observations on the stereochemistry of reduction of 2,6-dimethylcyclohexanones
Article Abstract:
Reduction of cis-2,6-dimethylcyclohexanone with NaBH4 in methanol produces axial alcohol which is an unexpected result. A careful study of NaBH4 and LiAlH4 reductions of cis- and trans-2,6- dimethylcyclohexanones has thus been made in various solvents. An unusual solvent effect exists. An important warning has been given for future stereochemical studies of this type, suggesting experimenters analyze isomer ratios before solvent evaporation to keep from altering product ratios.
Publication Name: Canadian Journal of Chemistry
Subject: Chemistry
ISSN: 0008-4042
Year: 1998
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