Search

Reports on the crystal structure of the complex of cholesterol oxidase with the steroid substrate dehydroisoandrosterone, refined at 1.8-Angstrom resolution. Cholesterol oxidases from Brevibacterium sterolicum; Hydrogen bonding of the hydroxyl group of the steroid substrate; Implications for flavin adenine dinucleotide dependent (FAD) alcohol oxidases.

Structures are of fundamental importance for diverse studies of lithium polysulfide clusters, which govern the performance of lithium-sulfur batteries. The ring-like geometries were regarded as the most stable structures, but their physical origin remains elusive. In this work, we systematically explored the minimal structures of Li 2 S x ( x = 4-8) clusters to uncover the driving force for their conformational preferences. All low-lying isomers were generated by performing global searches using the ABCluster program, and the ionic nature of the Li···S interactions was evidenced with the energy decomposition analysis based on the block-localized wave function (BLW-ED) approach and further confirmed with the quantum theory of atoms in molecule (QTAIM). By analysis of the contributions of various energy components to the relative stability with the references of the lowest-lying isomers, the controlling factor for isomer preferences was found to be the polarization interaction. Notably, although the electrostatic interaction dominates the binding energies, it contributes favorably to the relative stabilities of most isomers. The Li + ···Li + distance is identified as the key geometrical parameter that correlates with the strength of the polarization of the S x fragment imposed by the Li 2- cations. Further BLW-ED analyses reveal that the cooperativity of the Li + cations. Further BLW-ED analyses reveal that the cooperativity of the Li + cations primarily determines the relative strength of the polarization.

The exploration of novel inhibitors of the HCV NS4B protein that are based on a 2-oxadiazoloquinoline scaffold is described. Optimization to incorporate activity across genotypes led to a potent new series with broad activity, of which inhibitor 1 displayed the following EC50 values: 1a, 0.08 nM; 1b, 0.10 nM; 2a, 3 nM; 2b, 0.6 nM, 3a, 3.7 nM; 4a, 0.9 nM; 6a, 3.1 nM.