Chemical communication: conductors and insulators of screw-sense preference between helical oligo(aminoisobutyric acid) domains.
نویسندگان
چکیده
(1)H NMR studies quantify the abilities of achiral amino acids to communicate a left-handed screw-sense preference from one helical Aib(4) domain to another: certain quaternary amino acids (e.g. Ac(6)c) act as effective conductors of conformational preference while others (e.g. diphenylglycine) acts as insulators.
منابع مشابه
Controlling the sign and magnitude of screw-sense preference from the C-terminus of an achiral helical foldamer.
The global screw-sense preference of an achiral helical oligomer may be controlled by a single chiral monomer located at one terminus. Remarkably, maximal control is induced in oligomers of the achiral quaternary amino acid Aib by a single C-terminal alaninamide residue, probably because the Ala side chain, though small, is compatible with a 310 helical conformation. The presence or absence of ...
متن کاملDiastereotopic fluorine substituents as 19F NMR probes of screw-sense preference in helical foldamers.
Ligating simple amino alcohol or amino ester monomers containing enantiotopic fluorine substituents to the C-terminus of a helical peptide places the fluorine atoms in diastereotopic environments, and gives two distinct and easily identifiable signals in the (19)F NMR spectrum. In the case of a dynamically inverting helix built from achiral monomers, the chemical shift separation between the (1...
متن کاملDibenzazepinyl ureas as dual NMR and CD probes of helical screw-sense preference in conformationally equilibrating dynamic foldamers.
Conformationally mobile oligomers with helical structures, or 'dynamic foldamers', may populate a mixture of screw-sense conformers whose relative proportion has been used as a means of communicating information on a molecular scale. The dibenzazepinyl urea provides a means of quantifying both the sense and degree of this screw-sense preference through a combination of circular dichroism (CD) a...
متن کاملControllability of dynamic double helices: quantitative analysis of the inversion of a screw-sense preference upon complexation.
We describe a quantitative analysis of the complexation-induced inversion of a screw-sense preference based on a conformationally dynamic double-helix structure in a macrocycle. The macrocycle is composed of two twisting units (terephthalamide), which are spaced by two strands (1,3-bis(phenylethynyl)benzene), and is designed to generate a double-helix structure through twisting about a C2 axis ...
متن کاملConformational analysis of helical aminoisobutyric acid (Aib) oligomers bearing C-terminal ester Schellman motifs.
The effect of Schellman motifs on the adoption of stable 310 helical conformations in a series of aminoisobutyric (Aib) oligomers has been studied in the solid state and solution. The destabilising effect of the Schellman motif (a local inversion of helical screw-sense due to a C-terminal ester residue) was quantified in the solid state using X-ray crystallography through analysis of the torsio...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Chemical communications
دوره 48 28 شماره
صفحات -
تاریخ انتشار 2012