conformation

(redirected from conformationally)
Also found in: Dictionary, Thesaurus, Medical.

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
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Avmo et al., "Conformationally rigid nucleoside probes help understand the role of sugar pucker and nucleobase orientation in the thrombin-binding aptamer," Nucleic Acids Research, vol.
Dipole moment of conformationally restricted chiral biphenyl dopant 1 containing methyl, carboxylate and nitro functional groups at positions2(2?), 4(4?) and 5(5?) respectively, was calculated9.61 D whereas the dihedral angle between two rings(C2-C1-C1?-C2?) was found 54.6o and by comparing it with the reported values of dipole moment of benzene substituted derivatives, this was found veryhigh [13].
Using recombinant DNA technology, the L1 protein is expressed in Saccharomyces cerevisiae (yeast), and the proteins self-assemble into conformationally intact, noninfectious VLPs.
The highly interdisciplinary area includes organic and polymer synthesis, peptide design and synthesis, self-assembled macromolecules, computational studies to complement spectroscopic higher structural order determination, and interaction of conformationally (or higher structurally) organized oligomer polymers with biological systems.
In search of a universal combinatorial approach for the mimicry of peptide structure, his laboratory has developed effective protocols for creating conformationally biased peptide analogs and for introducing such surrogates into peptide mimic libraries in order to study various biological systems.
The facts noted here may suggest that Periphylla luciferase has a unique and unusual tertiary structure , and that the luciferases isolated by us are mixtures of two or more molecular species having conformationally different structures (having different activities) that are not easily separable by chromatography.
Eserine, on the other hand, was the only molecule to have its nitrogens conformationally restricted, and it had higher than expected activity.
Molecular recognition of the inhibiter ag-1343 by hiv-1 protease: Conformationally flexible docking by evolutionary programming.
These observations, as well as similar cytogenetic observations from a variety of murid and cricetid rodents (e.g., Murer-Orlando et al., 1983; Schmid et al., 1987; reviewed by Hale et al., 1991), indicate that pseudoautosomal heterochromatin is conformationally and compositionally distinct from autosomal heterochromatin within the same genome.
"Then we can make a molecule that has all of the features important for biological activity, but is conformationally constrained so it can't rotate or do anything else but look like the conformation that's recognized by the receptor or enzyme," Gadek continues.
Scott, "Targeting of a conformationally exposed, tumor-specific epitope of EGFR as a strategy for cancer therapy," Cancer Research, vol.
BMS631707 (7) possess a characteristic conformationally restricted azetidinone ring linked to the carboxylic acid group, which aids the drug to occupy a new hydrophobic pocket.