We identified conditions for heating and quick cooling viroid RNAs in the presence of salt which lead to the production of conformational isomers stable to incubation for at least 45 minutes at 30 degrees in the presence of magnesium ions. Elution in 0.3 M NaCl allowed the purification of an electrophoretically slow form of an in vitro transcript carrying a complete copy of the potato spindle t...

The diastereomers of ketones 2 and 3 are shown to exhibit distinct photochemical reactivities due to conformational preferences; while the anti isomers of 2 and 3 undergo efficient Yang cyclization in 75-90% yields with a remarkable diastereoselectivity (> 90%), the syn isomers predominantly undergo Norrish Type II elimination. The differences in the product profiles of the diastereomers are co...

Original crystal structures of even–even polyamides are introduced. They based on twisted conformations at the amide-aliphatic part links and reminiscent pleated rippled protein sheet introduced by Pauling Corey in early 1950s. Pleated sheets chiral, made two conformational isomers. have specific X-ray diffraction “profiles”. Publications describe such profiles, indicating that both variants ex...

Sugars are fundamental building blocks for living organisms and their interaction with proteins plays a central role in fundamental biological processes, such as energy storage and production, post-transductional modifications or immune response. Understanding those processes require deep knowledge of the forces that drive the interactions at the molecular level. Here we explore the interaction...

Cyclophanes of perylene tetracarboxylic diimides (PDIs) with different substituents at the bay positions, namely four phenoxy groups at the 1,7-positions (1), four piperidinyl groups at the 1,7-positions (2), and eight phenoxy groups at the 1,6,7,12-positions (3) of the two PDI rings, have been synthesized by the condensation of perylene dianhydride with amine in a dilute solution. These novel ...

Collagen prolyl 4-hydroxylases (CP4Hs) catalyze a prevalent posttranslational modification, the hydroxylation of (2S)-proline residues in protocollagen strands. The ensuing (2S,4R)-4-hydroxyproline residues are necessary for the conformational stability of the collagen triple helix. Prolyl peptide bonds isomerize between cis and trans isomers, and the preference of the enzyme is unknown. We syn...

It is important to identify proline cis/trans isomers that appear in several regulatory mechanisms of proteins, and characterize minor species are present due the conformational heterogeneity intrinsically disordered proteins (IDPs). To obtain residue level information on these mobile systems we introduce two 1Hα-detected, selective, real-time homodecoupled NMR experiments analyze abundant tran...

Monolayer films of n-propyl trichlorosilane (PTS) self-assembled on glass substrates were investigated using Fourier transform infrared spectroscopy (FTIR) and planar array infrared spectroscopic imaging (PA-IR spectroscopic imaging) as a function of three different solvents (hexane, benzene and toluene). The alkyl chain of a PTS monolayer has only two conformational isomers, gauche and trans. ...

The near-infrared (NIR) spectra of low-concentration (5 × 10(-3) M) solutions in CCl4 of basic aliphatic alcohols, methanol, ethanol, and 1-propanol were, for the first time, calculated by second-order vibrational perturbation theory computations and were compared with the corresponding experimental data. Density functional theory (DFT) using single hybrid (B3LYP) and double hybrid (B2PLYP) den...

In this work, we have investigated nonadiabatic dynamics in the vicinity of conical intersections for predissociation reactions of partially deuterated thioanisole molecules: C6H5S-CH2D and C6H5S-CHD2. Each isotopomer has two distinct rotational conformers according to the geometrical position of D or H of the methyl moiety with respect to the molecular plane for C6H5S-CH2D or C6H5S-CHD2, respe...