[strucure: see text]The conformational interconversions of several [2]catenanes containing a dibenzo-34-crown-10 ether (BPP34C10) interlocked with rings containing two 4,4'-dipyridyls tethered by different aryl spacers have been studied. Blocking groups on the tethers enabled the two pathways for circumrotation of the BPP34C10 to be open or blocked. The activation barrier for migration along the open tethers varied from 11 to 13 kcal/mol. This study demonstrates an ability to select the pathway for conformational interconversions in [2]catenanes.
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Biomolecules
November 2024
Department of Chemistry and Chemical Biology, Rutgers University, 123 Bevier Rd, Piscataway, NJ 08854, USA.
We demonstrate that a short oligonucleotide complementary to a G-quadruplex domain can invade this iconic, noncanonical DNA secondary structure in ways that profoundly influence the properties and differential occupancies of the resulting DNA polymorphic products. Our spectroscopic mapping of the conformational space of the associated reactants and products, both before and after strand invasion, yield unanticipated outcomes which reveal several overarching features. First, strand invasion induces the disruption of DNA secondary structural elements in both the invading strand (which can assume an iDNA tetrad structure) and the invaded species (a G-quadruplex).
View Article and Find Full Text PDFChem Asian J
January 2025
Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISER Bhopal) Bhauri, Bhopal Bypass Road, Bhopal, 462066, India.
Chiral amines and amino alcohols form an important category of molecules employed in the designing of new drugs and catalyst. Herein, we present a helically-twisted stereodynamic dialdehyde probe 1 for the determining of absolute configuration, and enantiomeric excess of chiral amine and amino alcohols. Probe 1 is based on the pyridine-2,6-dicarboxamide (PDC) core and undergoes rapid interconversion between the P- and M- conformers.
View Article and Find Full Text PDFJ Chem Inf Model
January 2025
Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Instituto Multidisciplinario de Investigaciones Biológicas (IMIBIO-SL). CONICET, Ejército de los Andes 950, 5700 San Luis, Argentina.
We report here a new ligand for the peroxisome-proliferator-activated receptor type α (PPARα), an N-tosyl hydrazone benzopyran that was designed throughout the mapping of the polar zone of the binding site of PPARα; such a compound displays a strong activity on this receptor that is comparable to that of the reference compound WY-14643. For the design of the -tosyl hydrazone benzopyran, we have carried out an exhaustive conformational study of WY-14643 and a previously reported hydrazine benzopyran derivative using conformational potential energy surfaces (PES). This study allowed us to map in a systematic way the entire binding site of the PPARα.
View Article and Find Full Text PDFChem Sci
December 2024
Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy of Precision Measurement, Chinese Academy of Sciences Wuhan 430071 China
Proteins typically adopt a single fold to carry out their function, but metamorphic proteins, with multiple folding states, defy this norm. Deciphering the mechanism of conformational interconversion of metamorphic proteins is challenging. Herein, we employed nuclear magnetic resonance (NMR), circular dichroism (CD), and all-atom molecular dynamics (MD) simulations to elucidate the mechanism of fold switching in proteins GA95 and GB95, which share 95% sequence homology.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States.
Aqueous solubilization of porphyrins, often accomplished with appended polar aryl groups, can also be achieved with symmetrically branched alkyl (i.e., swallowtail) groups terminated with polar moieties.
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