Different conformers can be stabilized for flexible porphyrins upon electron doping. The metastable flat conformer relaxes to the energetically favored distorted form, inducing spin switching in chelated nickel ion.

The protein-remodeling factor Hsp104 governs inheritance of [PSI+], a yeast prion formed by self-perpetuating amyloid conformers of the translation termination factor Sup35. Perplexingly, either excess or insufficient Hsp104 eliminates [PSI+]. In vitro, at low concentrations, Hsp104 catalyzed the formation of oligomeric intermediates that proved critical for the nucleation of Sup 35 fibrillizat...

The stabilities, optimized molecular geometries, APT charges and vibrational characteristics for the nicotinic acid (NA) and 2-fluoronicotinic acid (2-FNA) have been studied theoretically using density functional theory (DFT) methods. The E (trans) conformers of nicotinic acid are found to be more stable and less polar than their respective Z (cis) conformers. Most of the vibrational frequencie...

Natively unfolded regions have been shown to be common in functional proteins in a vast range of biochemical processes. In contrast to classical structural biology, unfolded proteins must be described by an ensemble of intermediate conformers. The traditional NMR approach, which has been widely used for structure determination in classical structural biology, is still feasible for the study of ...

Photoreaction of zinc methyl 20-substituted meso(pyro)pheophorbide-a prepared by modifying naturally occurring chlorophyll-a in the presence of oxygen molecules gave its C19-C20 oxidative cleavage (1-carbonyl-19-oxo-bilatrienes) as the major products and the regioisomeric C1-C20 cleavage (19-carbonyl-1-oxo-bilatrienes) as the minor products. The resulting zinc complexes of linear tetrapyrroles ...

Characterized by microwave spectroscopy after their formation in a supersonic jet, the axial and equatorial hydrogen bond conformers of the title complex were studied. The axial form--shown in the picture--has been found to be the most stable one. The experimental data are consistent with a C(s) symmetry for both conformers, in which linear hydrogen bonds lying in the symmetry plane bisect the ...

Ibuprofen's pain-relieving properties arise from its ability to physically block the active site of an enzyme, thus making its structural and conformational properties highly interesting. We here present a conformer-selective high-resolution broadband rotational spectroscopy study of gas-phase ibuprofen. The interpretation of the spectroscopic results is supported by quantum-chemical calculatio...

The isomerism of zinc complex [Zn(L)2]2+ with tridentate ligand L having acetamide and pyridine groups on each side the central amino- nitrogen atom has been investigated by DFT calculations, liquid state NMR single-crystal X-ray diffraction. was used for obtaining ensembles low-energy conformers calculation parameters all conformers. For generated [Zn(L)2]2+, Mean Absolute Error [MAE(conf)] te...

We report optimization of single-strand conformation polymorphism (SSCP) analysis in the presence of polyethylene glycol. The protocol developed separates single-strand conformers in a much shorter time (1-3 h) than conventional SSCP protocols and broadens the applicability of SSCP analysis from 150 to as much as 500 bp of DNA by different percentages of GC content present. We conclude that add...

In the present work, a quantum chemical study (Semi-empirical,PM6 method) is performed using nitrogen mustards (HN1, HN2 and HN3) as subjects in order to demonstrate that there is a close relationship between pharmacological activity and parameters such as formation enthalpy and number of conformers, which could, consequently, be employed as reliable QSAR descriptors. To the studied nitrogen mu...