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Full-Text Articles in Life Sciences
Relation Between Halogen Bond Strength And Ir And Nmr Spectroscopic Markers, Akhtam Amonov, Steve Scheiner
Relation Between Halogen Bond Strength And Ir And Nmr Spectroscopic Markers, Akhtam Amonov, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The relationship between the strength of a halogen bond (XB) and various IR and NMR spectroscopic quantities is assessed through DFT calculations. Three different Lewis acids place a Br or I atom on a phenyl ring; each is paired with a collection of N and O bases of varying electron donor power. The weakest of the XBs display a C–X bond contraction coupled with a blue shift in the associated frequency, whereas the reverse trends occur for the stronger bonds. The best correlations with the XB interaction energy are observed with the NMR shielding of the C atom directly bonded …
C···O And Si···O Tetrel Bonds: Substituent Effects And Transfer Of The Sif3 Group, Zhihao Niu, Qiaozhuo Wu, Qingzhong Li, Steve Scheiner
C···O And Si···O Tetrel Bonds: Substituent Effects And Transfer Of The Sif3 Group, Zhihao Niu, Qiaozhuo Wu, Qingzhong Li, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The tetrel bond (TB) between 1,2-benzisothiazol-3-one-2-TF3-1,1-dioxide (T = C, Si) and the O atom of pyridine-1-oxide (PO) and its derivatives (PO-X, X = H, NO2, CN, F, CH3, OH, OCH3, NH2, and Li) is examined by quantum chemical means. The Si···O TB is quite strong, with interaction energies approaching a maximum of nearly 70 kcal/mol, while the C···O TB is an order of magnitude weaker, with interaction energies between 2.0 and 2.6 kcal/mol. An electron-withdrawing substituent on the Lewis base weakens this TB, while an electron-donating group has the opposite …
Arginine-178 Is An Essential Residue For Itpa Function, Nicholas E. Burgis, Caitlin April, Kandise Vanwormer
Arginine-178 Is An Essential Residue For Itpa Function, Nicholas E. Burgis, Caitlin April, Kandise Vanwormer
Chemistry and Biochemistry Faculty Publications
The inosine triphosphate pyrophosphatase (ITPA) enzyme plays a critical cellular role by removing noncanonical nucleoside triphosphates from nucleotide pools. One of the first pathological ITPA mutants identified is R178C (rs746930990), which causes a fatal infantile encephalopathy, termed developmental and epileptic encephalopathy 35 (DEE 35). The accumulation of noncanonical nucleotides such as inosine triphosphate (ITP), is suspected to affect RNA and/or interfere with normal nucleotide function, leading to development of DEE 35. Molecular dynamics simulations have shown that the very rare R178C mutation does not significantly perturb the overall structure of the protein, but results in a high level of structural …