High impact information on Conformer A

• Application of the rapid equilibrium model between two possible conformers revealed that conformer A with an intramolecular Se...F interaction is more stable in enthalpy (DeltaH) by 1.23 kcal/mol for 1a (in CD2Cl2) and by 0.85 and 0.83 kcal/mol for 1e (in CD2Cl2 and CD3CN, respectively) than conformer B, which does not have close Se...F contact [1].
• Conformer B is folded back away from the active site in a unique position [2].
• On the other hand, o,o'-diisopropylbenzophenone (2) is predicted by calculations to exist essentially as a C2-type conformer, a result that was confirmed by the low-temperature NMR spectra [3].
• In water solution, the tautomer LH2 +/- is present as conformer A (96%) [4].
• Recent studies showed that A beta 1-40 can adopt two different conformational states in solution (an amyloidogenic conformer, A beta ac, and a non-amyloidogenic conformer, A beta nac) which have distinct abilities to form amyloid fibrils [5].

Associations of Conformer A with other chemical compounds

• In the C2 lattice, the phthaloyl moiety binds in two extended conformations, A and C, with each conformer having a 180 degrees flip of the o-carboxylate group, and a third, lower occupancy conformer B, with the phthaloyl group folded within contact of the active-site pocket [2].
• It is designated as conformer B and is characterized by an attractive contact between the substrate's glycinic N atom and the active site cysteine S atom [6].

References