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Full-Text Articles in Physical Sciences and Mathematics
Structural Analysis Of Alpha-Fetoprotein (Afp)-Like Peptides With Anti-Breast-Cancer Properties, Berhane Temelso, Katherine Alser, Arianne Gauthier, Amber Palmer, George Shields
Structural Analysis Of Alpha-Fetoprotein (Afp)-Like Peptides With Anti-Breast-Cancer Properties, Berhane Temelso, Katherine Alser, Arianne Gauthier, Amber Palmer, George Shields
Berhane Temelso
The abundance of alpha-fetoprotein (AFP), a natural protein produced by the fetal yolk sac during pregnancy, correlates with lower incidence of estrogen receptor positive (ER+) breast cancer. The pharmacophore region of AFP has been narrowed down to a four amino acid (AA) region in the third domain of the 591 AA peptide. Our computational study focuses on a 4-mer segment consisting of the amino acids threonine-proline-valine-asparagine (TPVN). We have run replica exchange molecular dynamics (REMD) simulations and used 120 configurational snapshots from the total trajectory as starting configurations for quantum chemical calculations. We optimized structures using semiempirical (PM3, PM6, PM6-D2, …
Hydration Of The Bisulfate Ion: Atmospheric Implications, Devon Husar, Berhane Temelso, Alexa Ashworth, George Shields
Hydration Of The Bisulfate Ion: Atmospheric Implications, Devon Husar, Berhane Temelso, Alexa Ashworth, George Shields
Berhane Temelso
Using molecular dynamics configurational sampling combined with ab initio energy calculations, we determined the low energy isomers of the bisulfate hydrates. We calculated the CCSD(T) complete basis set (CBS) binding electronic and Gibbs free energies for 53 low energy isomers of HSO4–(H2O)n=1–6 and derived the thermodynamics of adding waters sequentially to the bisulfate ion and its hydrates. Comparing the HSO4–/H2O system to the neutral H2SO4/H2O cluster, water binds more strongly to the anion than it does to the neutral molecules. The difference in the binding thermodynamics of HSO4–/H2O and H2SO4/H2O systems decreases with increasing number of waters. The thermodynamics for …
Structures Of Cage, Prism, And Book Isomers Of Water Hexamer From Broadband Rotational Spectroscopy, Cristóbal Pérez, Matt Muckle, Daniel Zaleski, Nathan Seifert, Berhane Temelso, George Shields, Zbigniew Kisiel, Brooks Pate
Structures Of Cage, Prism, And Book Isomers Of Water Hexamer From Broadband Rotational Spectroscopy, Cristóbal Pérez, Matt Muckle, Daniel Zaleski, Nathan Seifert, Berhane Temelso, George Shields, Zbigniew Kisiel, Brooks Pate
Berhane Temelso
Theory predicts the water hexamer to be the smallest water cluster with a three-dimensional hydrogen-bonding network as its minimum energy structure. There are several possible low-energy isomers, and calculations with different methods and basis sets assign them different relative stabilities. Previous experimental work has provided evidence for the cage, book, and cyclic isomers, but no experiment has identified multiple coexisting structures. Here, we report that broadband rotational spectroscopy in a pulsed supersonic expansion unambiguously identifies all three isomers; we determined their oxygen framework structures by means of oxygen-18–substituted water (H218O). Relative isomer populations at different expansion conditions establish that the …
Quantum Mechanical Study Of Sulfuric Acid Hydration: Atmospheric Implications, Berhane Temelso, Thomas Morrell, Robert Shields, Marco Allodi, Elena Wood, Karl Kirschner, Thomas Castonguay, Kaye Archer, George Shields
Quantum Mechanical Study Of Sulfuric Acid Hydration: Atmospheric Implications, Berhane Temelso, Thomas Morrell, Robert Shields, Marco Allodi, Elena Wood, Karl Kirschner, Thomas Castonguay, Kaye Archer, George Shields
Berhane Temelso
The role of the binary nucleation of sulfuric acid in aerosol formation and its implications for global warming is one of the fundamental unsettled questions in atmospheric chemistry. We have investigated the thermodynamics of sulfuric acid hydration using ab initio quantum mechanical methods. For H2SO4(H2O)n where n = 1–6, we used a scheme combining molecular dynamics configurational sampling with high-level ab initio calculations to locate the global and many low lying local minima for each cluster size. For each isomer, we extrapolated the Møller–Plesset perturbation theory (MP2) energies to their complete basis set (CBS) limit and added finite temperature corrections …
Rotational And Hyperfine Analysis Of The E-X Electronic Transition Of Tao, Casey Christopher, Stephanie Lee, Francis Gwandu, Andrew Matsumoto, Benjamin Knurr, Thomas Mahle, Zachary Morrow, Thomas Varberg
Rotational And Hyperfine Analysis Of The E-X Electronic Transition Of Tao, Casey Christopher, Stephanie Lee, Francis Gwandu, Andrew Matsumoto, Benjamin Knurr, Thomas Mahle, Zachary Morrow, Thomas Varberg
Thomas D. Varberg
No abstract provided.