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991.
Cooperative,Reversible Self‐Assembly of Covalently Pre‐Linked Proteins into Giant Fibrous Structures
Saadyah Averick Orsolya Karcsony Jacob Mohin Xin Yong Nicholas M. Moellers Bradley F. Woodman Weipu Zhu Ryan A. Mehl Anna C. Balazs Tomasz Kowalewski Krzysztof Matyjaszewski 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(31):8188-8193
We demonstrate a simple bioconjugate polymer system that undergoes reversible self‐assembling into extended fibrous structures, reminiscent of those observed in living systems. It is comprised of green fluorescent protein (GFP) molecules linked into linear oligomeric strands through click step growth polymerization with dialkyne poly(ethylene oxide) (PEO). Confocal microscopy, atomic force microscopy, and dynamic light scattering revealed that such strands form high persistence length fibers, with lengths reaching tens of micrometers, and uniform, sub‐100 nm widths. We ascribe this remarkable and robust form of self‐assembly to the cooperativity arising from the known tendency of GFP molecules to dimerize through localized hydrophobic patches and from their covalent pre‐linking with flexible PEO. Dissipative particle dynamics simulations of a coarse‐grained model of the system revealed its tendency to form elongated fibrous aggregates, suggesting the general nature of this mode of self‐assembly. 相似文献
992.
Robert A. Kowtoniuk Tao Pei Caitlin M. DeAngelo Jacob H. Waldman Erin N. Guidry J. Michael Williams Robert M. Garbaccio Stephanie E. Barrett 《Journal of polymer science. Part A, Polymer chemistry》2014,52(10):1385-1391
l ‐Ornithine‐based poly(peptides) have been widely utilized in the field of drug delivery, however few studies have been conducted examining the details of polymerization. In this article, the effects of monomer concentration, polymerization kinetics, polymer molecular weight and monomer purity were investigated using l ‐carboxybenzyl (Cbz)‐ornithine as a model monomer. The mechanism of polymerization herein follows the normal amine mechanism to produce poly(peptides) having controlled molecular weights, known chain ends and a narrow polydispersity index (PDI). A preferred monomer concentration range was determined, which required minimal polymerization times and allowed for predictable and reproducible molecular weights with narrow PDIs. The impact of monomer purity on the polymerization was established and monomer purification conditions are reported, which produce high‐purity monomer after a single recrystallization. Additionally, the optimized polymerization conditions and monomer purification protocol were combined with a sequential monomer addition technique to produce high molecular weight poly(ornithine) with a narrow PDI and known chain ends. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1385–1391 相似文献
993.
Reynolds Jacob G. Cooke Gary A. Page Jason S. Warrant R. Wade 《Journal of Radioanalytical and Nuclear Chemistry》2018,316(1):289-299
Journal of Radioanalytical and Nuclear Chemistry - Uranium is the most prevalent radioactive element in the 210 million liters of nuclear waste at the Hanford Site but the uranium speciation has... 相似文献
994.
Jacob M. Wahlen-Strothman Thomas M. Henderson Gustavo E. Scuseria 《Molecular physics》2018,116(2):186-193
Doubly occupied configuration interaction (DOCI), the exact diagonalisation of the Hamiltonian in the paired (seniority zero) sector of the Hilbert space, is a combinatorial cost wave function that can be very efficiently approximated by pair coupled cluster doubles (pCCD) at mean-field computational cost. As such, it is a very interesting candidate as a starting point for building the full configuration interaction (FCI) ground state eigenfunction belonging to all (not just paired) seniority sectors. The true seniority zero sector of FCI (referred to here as FCI0) includes the effect of coupling between all seniority sectors rather than just seniority zero, and is, in principle, different from DOCI. We here study the accuracy with which DOCI approximates FCI0. Using a set of small Hubbard lattices, where FCI is possible, we show that DOCI ~ FCI0 under weak correlation. However, in the strong correlation regime, the nature of the FCI0 wavefunction can change significantly, rendering DOCI and pCCD a less than ideal starting point for approximating FCI. 相似文献
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Shiva K. Rastogi Robert A. Rogers Justin Shi Christopher T. Brown Cindy Salinas Katherine M. Martin Jacob Armitage Christopher Dorsey Gao Chun Peter Rinaldi William J. Brittain 《Magnetic resonance in chemistry : MRC》2016,54(2):126-131
We report through‐space (TS) 19F–19F coupling for ortho‐fluoro‐substituted Z ‐azobenzenes. The magnitude of the TS‐coupling constant (TSJFF) ranged from 2.2–5.9 Hz. Using empirical formulas reported in the literature, these coupling constants correspond to non‐bonded F–F distances (dFF) of 3.0–3.5 Å. These non‐bonded distances are significantly smaller than those determined by X‐ray crystallography or density functional theory, which argues that simple models of 19F–19F TS spin–spin coupling solely based dFF are not applicable. 1H, 13C and 19F data are reported for both the E and Z isomers of ten fluorinated azobenzenes. Density functional theory [B3YLP/6‐311++G(d,p)] was used to calculate 19F chemical shifts, and the calculated values deviated 0.3–10.0 ppm compared with experimental values. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Corrigendum: A Photocleavable Masked Nuclear‐Receptor Ligand Enables Temporal Control of C. elegans Development
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