conformation

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conformation

Chem
a. another name for configuration
b. one of the configurations of a molecule that can easily change its shape and can consequently exist in equilibrium with molecules of different configuration

Conformation

 

(of molecules), geometric forms that molecules of organic compounds can assume during the rotation of atoms or groups of atoms (substituents) about single bonds while maintaining the order of the chemical bonding of the atoms (chemical structures), the bond lengths, and valency angles. Molecules that differ from one another only in conformation are called conformers, or rotational isomers. The existence of conformations is determined by the spatial interaction (such as repulsion, attraction, and hydrogen bond formation) of substituents (hydrogen atoms included) that are not bonded to one another. One such example (see Figure 1) is represented by several planar conformations of a pentane molecule:

CH3—CH2—CH2—CH2—CH3

Unlike geometric and optical isomers, conformers under general conditions easily convert into one another (without the breaking of bonds) and therefore cannot be isolated (compareCONFIGURATION). The molecules of organic compounds usually exist in the form of a mixture of conformers that are in equilibrium,

Figure 1. Planar conformations of a pentane molecule: (a) zigzag, (b) claw-shaped, (c) irregular

among which those that are energetically most favorable, that is, exhibiting the lowest energy, predominate. The conformational state of molecules affects the physical properties of substances and the orientation and rate of chemical transformations (see).

V. M. POTAPOV

conformation

[kän·fər′mā·shən]
(organic chemistry)
In a molecule, a specific orientation of the atoms that varies from other possible orientations by rotation or rotations about single bonds; generally in mobile equilibrium with other conformations of the same structure. Also known as conformational isomer; conformer.
References in periodicals archive ?
1] receptor in the agonist conformation, and the first structure for the Orexin-2 receptor in an antagonist confirmation.
In both of these configuration examples, the carbon-carbon backbone of PMVC adopts the all-trans conformations and dipole orientations are similar.
It is clear that the steric effects of an individual ester moiety among the monomeric units are similar in most conformations.
The structure was similar to the earlier reported R-state structures, but there were differences in many side-chain conformations, the presence of a phosphate ion, and the position of the associated water structure.
At the Tm, there is a definite change in volume due to the highly ordered reduced entropy conformation of the polymer chain in the crystalline state.
The collaboration will leverage the synergy between Integral Molecular's Lipoparticle technology for immunization with native conformation multispanning membrane proteins and Crystal's GEM technology for the recovery of monoclonal antibodies against otherwise conserved proteins raised in immunized chickens.
In the eclipsed conformation, close carbon-hydrogen bonds crowd each other, thereby raising the molecule's overall energy.
A model of the fiber morphology is introduced to explain the rubber-elastic behavior: small micel-like crystals containing molecules in the planar all-trans conformation act as physical crosslinks in the amorphous matrix.
The polymer chains reorient to the lower entropy conformation with almost no frictional resistance due to the viscous component.
NASDAQ: CGEN) announced today the development of amethod to identify novel therapeutic candidates to interfere with disease associated protein conformations and protein-protein interactions.
Free energy calculations can sample many different conformations and provide a clear picture of the mechanisms of inhibitor binding.