1999, "Equilibrium and kinetics of rotamer
interconversion in immunosuppressant prodigiosin derivatives in solution," J.
There is evidence in the literature to indicate that the two peaks observed in the NMR spectrum are most probably due to rotation about the N-N bond, altering the field on the amide carbonyl (47) (48) and thereby giving rise to two rotamer
forms, as illustrated in the inset of Fig.
00 ppm (in a 5:1 ratio), each one corresponding to one rotamer
All the data collected indicates there are two conformers; the anti conformer is the more stable rotamer
and the gauche conformer in the fluid states but only the gauche conformer in the poly-crystalline solid.
Protein Sidechain Database for homology modeling, rotamer
exploration and mutation.
To predict the probabilistic likelihood for the particular rotamer
of a given SC in the model, the distribution of the [[chi].
4 in which the influence of the THF ring's orientation on the potential energy of the rotamers
The density for Br2' is weaker than that for Br4', likely due to different rotamers
of the second ring, which would maintain the position of Br4' but reposition Br2' in multiple orientations.
Two of these are dual-conformation peptide units; the remainder involves alternate rotamers
of side chains either alone or in small clusters.
The relative energies of rotamers
range between 0 to 16 kcal/mol.
Briefly, the lowest energy rotamers
present a syn methylester group on an E side chain with a pseudo H-bond between the hydroxy H and the prenyl [pi] density (Fig.
Complete equilibrium geometries have been determined for both rotamers
by ab initio calculations employing a variety of basis sets up to 6-311+G(2d,2p) at levels of restricted Hartree-Fock (RHF) and/or Moller Plesset (MP) to second order.