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Articles 1 - 7 of 7

Full-Text Articles in Physical Sciences and Mathematics

Interplay Of Hydrogen Bonds And N→Π* Interactions In Proteins, Gail J. Bartlett, Robert W. Newberry, Brett Vanveller, Ronald T. Raines, Derek N. Woolfson Nov 2013

Interplay Of Hydrogen Bonds And N→Π* Interactions In Proteins, Gail J. Bartlett, Robert W. Newberry, Brett Vanveller, Ronald T. Raines, Derek N. Woolfson

Brett VanVeller

Protein structures are stabilized by multiple weak interactions, including the hydrophobic effect, hydrogen bonds, electrostatic effects, and van der Waals interactions. Among these interactions, the hydrogen bond is distinct in having its origins in electron delocalization. Recently, another type of electron delocalization, the n→π* interaction between carbonyl groups, has been shown to play a role in stabilizing protein structure. Here we examine the interplay between hydrogen bonding and n→π* interactions. To address this issue, we used data available from high-resolution protein crystal structures to interrogate asparagine side-chain oxygen atoms that are both acceptors of a hydrogen bond and donors of …


Detection Of Boronic Acids Through Excited-State Intramolecular Proton-Transfer Fluorescence, Matthew R. Aronoff, Brett Vanveller, Ronald T. Raines Oct 2013

Detection Of Boronic Acids Through Excited-State Intramolecular Proton-Transfer Fluorescence, Matthew R. Aronoff, Brett Vanveller, Ronald T. Raines

Brett VanVeller

Boronic acids are versatile reagents for the chemical synthesis of organic molecules. They and other boron-containing compounds can be detected readily by the interruption of the excited-state intramolecular proton transfer (ESIPT) of 10-hydroxybenzo[h]quinolone. This method is highly sensitive and selective, and useful for monitoring synthetic reactions and detecting boron-containing compounds on a solid support.


A Divalent Protecting Group For Benzoxaboroles, Brett Vanveller, Matthew R. Aronoff, Ronald T. Raines Sep 2013

A Divalent Protecting Group For Benzoxaboroles, Brett Vanveller, Matthew R. Aronoff, Ronald T. Raines

Brett VanVeller

1-Dimethylamino-8-methylaminonaphthalene is put forth as a protecting group for benzoxaboroles. The ensuing complex is fluorescent, charge-neutral, highly stable under basic conditions, stable to anhydrous acid, and readily cleavable in aqueous acid to return the free benzoxaborole.


N→Π* Interactions Of Amides And Thioamides: Implications For Protein Stability, Robert W. Newberry, Brett Vanveller, Ilia A. Guzei, Ronald T. Raines May 2013

N→Π* Interactions Of Amides And Thioamides: Implications For Protein Stability, Robert W. Newberry, Brett Vanveller, Ilia A. Guzei, Ronald T. Raines

Brett VanVeller

Carbonyl–carbonyl interactions between adjacent backbone amides have been implicated in the conformational stability of proteins. By combining experimental and computational approaches, we show that relevant amidic carbonyl groups associate through an n→π* donor–acceptor interaction with an energy of at least 0.27 kcal/mol. The n→π* interaction between two thioamides is 3-fold stronger than between two oxoamides due to increased overlap and reduced energy difference between the donor and acceptor orbitals. This result suggests that backbone thioamide incorporation could stabilize protein structures. Finally, we demonstrate that intimate carbonyl interactions are described more completely as donor–acceptor orbital interactions rather than dipole–dipole interactions.


Polycyclic Aromatic Triptycenes: Oxygen Substitution Cyclization Strategies, Brett Vanveller, Derek J. Schipper, Timothy M. Swager Apr 2012

Polycyclic Aromatic Triptycenes: Oxygen Substitution Cyclization Strategies, Brett Vanveller, Derek J. Schipper, Timothy M. Swager

Brett VanVeller

The cyclization and planarization of polycyclic aromatic hydrocarbons with concomitant oxygen substitution was achieved through acid catalyzed transetherification and oxygen-radical reactions. The triptycene scaffold enforces proximity of the alcohol and arene reacting partners and confers significant rigidity to the resulting π-system, expanding the tool set of iptycenes for materials applications.


Experimental And Molecular Dynamics Investigation Into The Amphiphilic Nature Of Sulforhodamine B, Baris E. Polat, Shangchao Lin, Jonathan D. Mendenhall, Brett Vanveller, Robert Langer, Daniel Blankschtein Jan 2011

Experimental And Molecular Dynamics Investigation Into The Amphiphilic Nature Of Sulforhodamine B, Baris E. Polat, Shangchao Lin, Jonathan D. Mendenhall, Brett Vanveller, Robert Langer, Daniel Blankschtein

Brett VanVeller

Sulforhodamine B (SRB), a common fluorescent dye, is often considered to be a purely hydrophilic molecule, having no impact on bulk or interfacial properties of aqueous solutions. This assumption is due to the high water solubility of SRB relative to most fluorescent probes. However, in the present study, we demonstrate that SRB is in fact an amphiphile, with the ability to adsorb at an air/water interface and to incorporate into sodium dodecyl sulfate (SDS) micelles. In fact, SRB reduces the surface tension of water by up to 23 mN/m, and the addition of SRB to an aqueous SDS solution induces …


The Synthesis Of Azaperylene-9,10-Dicarboximides, Brett Vanveller, Kojl Miki, Timorthy M. Swager Jan 2010

The Synthesis Of Azaperylene-9,10-Dicarboximides, Brett Vanveller, Kojl Miki, Timorthy M. Swager

Brett VanVeller

The efficient synthesis of a hydrophilic monomer bearing a three-dimensional noncompliant array of hydroxyl groups is described that prevents water-driven excimer features of hydrophobic poly(p-phenylene ethynylene) backbones. Sensitivity of the polymer to 3-nitrotyrosine is also discussesd.