The implicit membrane model IMM1 is extended to include the membrane dipole potential and applied to molecular dynamics simulations of the helical peptides alamethicin, WALP23, influenza hemagglutinin fusion peptide, HIV fusion peptide, magainin, and the pre-sequence of cytochrome c oxidase subunit IV (p25). The results show that the orientation of the peptides in the membrane can be influenced by the dipole potential. The binding affinity of all peptides except for the hemagglutinin fusion peptide decreases upon increase of the dipole potential. The changes in both orientation and binding affinity are explained by the interaction of the dipole potential with the helix backbone dipole and ionic side-chains. In general, peptides that tend to insert the N-terminus in the membrane and/or have positively charged side chains will lose binding affinity upon increase of the dipole potential.
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http://dx.doi.org/10.1016/j.bpc.2011.10.002 | DOI Listing |
J Phys Chem A
January 2025
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
High-level multireference configuration interaction plus Davidson correction (MRCI + Q) calculation method was employed to determine the potential energy curves (PECs) of 10 Λ-S states, which come from the first and second dissociation channels of the SbP molecule, as well as 34 Ω states considering the spin-orbit coupling (SOC) effect. By solving the Schrödinger equation for nuclear motion, spectroscopic constants for the ground state XΣ and low-lying excited states were obtained and compared with experimental data. The excellent agreement indicates the reliability of our calculations.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, USA.
This study investigates the impact of structural isomerism on the excited state lifetime and redox energetics of heteroleptic [Ir(ppy)2(bpy)]+ and homoleptic Ir(ppy)3 photoredox catalysts using ground-state and time-dependent density functional theory methods. While the ground- and excited-state reduction potentials differ only slightly among the isomers of these complexes, our findings reveal significant variations in the radiative and non-radiative decay rates of the reactivity-controlling triplet 3MLCT states of these closely related species. The observed differences in radiative decay rates could be traced back to variations in the transition dipole moment, vertical energy gaps, and spin-orbit coupling of the isomers.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, United States.
The photocatalytic efficiency of materials such as graphene and noble metal nanoclusters depends on their plasmon lifetimes. Plasmon dephasing and decay in these materials is thought to occur on ultrafast time scales, ranging from a few femtoseconds to hundreds of femtoseconds and longer. Here we focus on understanding the dephasing and decay pathways of excited states in small lithium and silver clusters and in plasmonic states of the π-conjugated molecule anthracene, providing insights that are crucial for interpreting optical properties and photophysics.
View Article and Find Full Text PDFJ Mol Graph Model
January 2025
Department of Physics, Institute of Science, Banaras Hindu University, Varanasi, India. Electronic address:
This study investigates the interaction of a synthetic bio-relevant molecule with C and BN nanorings, exploring their potential applications in sensing and drug delivery. Employing Density Functional Theory (DFT) at the ωB97XD level with the 6-31G(d,p) basis set, we computed the adsorption and electronic properties of the resulting nanocomplexes. A total of ten distinct configurations were identified for the interactions, with adsorption energies ranging from -6.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Physics and Optoelectronic Engineering, Shenzhen University Shenzhen 518060 China
Thin film transistors (TFTs) with InSnZnO (ITZO) and AlO as the semiconductor and dielectric layers, respectively, were investigated, aiming to elevate the device performance. Chemically synthesized CuInS/ZnS core/shell colloidal quantum dots (QDs) were used to passivate the semiconductor/dielectric interface. Compared with the pristine device, the device with the integrated QDs demonstrates remarkably improved electrical performance, including a higher electron mobility and a lower leakage current.
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