A double-stranded β-helix with antiparallel chains in a crystalline oligo-L–D-peptide

Self-Assembling Organic Nanotubes

“…[43,44] The compound crystallized as a C 2symmetrical left-handed double b 5.6 -helix. Later NMR studies supported the existence of similar left-handed double helical structures in solution.…”

β‐Helical structures of Boc‐(L‐Val‐D‐Val)6‐OMe in the crystalline state and in chloroform

“…spectra for Nujol mulls show that the crystal structure of samples 12-A of Boc-(L-Val-D-Val),-OMe is predominantly a double-stranded P-helical structure of the type r L j 5 . 6 , with left-handed sense of twist, like that of Boc-(L-Val-D-Val)4-OMe [3]. The data available so far do not allow any conclusion regarding the type of crystal structure for samples 12-B of the dodecapeptide.…”

Synthesis and Function of Double‐Stranded Helical Polymers and Oligomers

“…Interestingly, the double helix formation is highly affected by the nature of the transition metals: the same bispyridine ligand reacted with a Pd 2þ ion to form a similar metallopolymer (poly-10-Pd), but resulting in a lamellar structure. Yamaguchi and coworkers recently reported that optically active acyclic ethynylhelicene oligomers (11) folded into a double helical structure through solvophobic effects as supported by 1 H NMR, CD, and VPO measurements. [54] The double helix formation is sensitive to the solvents and was predominant in benzene, whereas the oligomer strands unraveled into a single-stranded random-coiled structure in chloroform.…”

“…For example, the right-handed double helical structure of DNA is the requisite factor for the storage, transmission, and translation of genetic information. Naturally occurring proteins, gramicidins, and collagen that are composed of a unique sequence of oligopeptides assemble into left-and right-handed double and triple helices to form ion channels [1][2][3] and microfibrils, [4] respectively. Another important biological polymers, polysaccharides also possess multi-stranded helical structures; amylose, one of the major components of starch, takes a left-handed single helical structure in an aqueous media, while it folds into a double helix in the solid state.…”