Other Chemistry Commons^™

Patent: Cell-Permeable Miniature Proteins, Alanna S. Schepartz, Douglas S. Daniels, Betsy Smith

Chemistry Faculty Publications

Abstract: The present invention generally relates to miniature proteins, including miniature proteins that are permeable to cells. Certain aspects of the invention are generally related to miniature proteins, such as avian pancreatic polypeptide (aPP), modified such that the miniature proteins are permeable to cells. For instance, a portion of the aPP, such as the alpha helix region and/or the type II polyproline helix region, may be modified to render the region substantially cationic. As an example, one or more residues may be substituted with cationic amino acid residues such as arginine. The miniature proteins may also have additional functions, such …

Localised Galvanic Corrosion Processes In Thermal Spray Coated/Cast Aluminium Alloy Systems, David Culliton, Tony Betts, David Kennedy

Conference Papers

Cast Aluminium Alloys, because of the propensity of aluminium to react with impurities and alloying elements, are prone to developing IM impurities during the solidification process. These IM phases can act, in some fluids, as initiation sites for localised corrosion processes, resulting in degradation phenomena, such as pitting. Whilst Thermal Spray coatings can improve the wear resistance of Cast Aluminium Alloys, their corrosion performance may be hampered by the presence of through porosity within the coating.

The present work details some preliminary studies of the localised corrosion processes occurring at the interface area between a Thermal Spray coating and a …

Inverse Velocity Dependence Of Vibrationally Promoted Electron Emission From A Metal Surface, N. H. Nahler, J. D. White, Jerry L. Larue, Daniel J. Auerbach, Alec M. Wodtke

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

All previous experimental and theoretical studies of molecular interactions at metal surfaces show that electronically nonadiabatic influences increase with molecular velocity. We report the observation of a nonadiabatic electronic effect that follows the opposite trend: The probability of electron emission from a low–work function surface—Au(111) capped by half a monolayer of Cs—increases as the velocity of the incident NO molecule decreases during collisions with highly vibrationally excited NO(X²π_½, V = 18; V is the vibrational quantum number of NO), reaching 0.1 at the lowest velocity studied. We show that these results are consistent with a vibrational …

The Work Function Of Submonolayer Cesium-Covered Gold: A Photoelectron Spectroscopy Study, Jerry L. Larue, J. D. White, N. H. Nahler, Z. Liu, Y. Sun, P. A. Pianetta, Daniel J. Auerbach, Alec M. Wodtke

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Using visible and x-ray photoelectron spectroscopy, we measured the work function of a Au(111) surface at a well-defined submonolayer coverage of Cs. For a Cs coverage producing a photoemission maximum with a He–Ne laser, the work function is , consistent with previous assumptions used to analyze vibrationally promoted electron emission. A discussion of possible Cs layer structures is also presented.

Surface Charge Effects Involved In The Control Of Stability Of Sols Comprising Uniform Cholesterol Particles, Vuk Uskoković

Pharmacy Faculty Articles and Research

The reported is a method for the preparation of stable dispersions of narrowly dispersed cholesterol crystals, which may provide an excellent model for the aggregation studies thereof. The effects of experimental parameters that include concentration, pH, ionic strength, temperature, and aging on the resulting morphologies are acknowledged. Regardless of the cause of destabilization, the multilayered aggregates of cholesterol particles are formed by “face-to-face” stacking of the original platelets, as promoted by higher surface charge density on particle sides comparing to their faces. In accordance with the crucial involvement of surface charge effects in stabilization of cholesterol dispersions produced hereby, aggregation …

Seminaphthofluorones Are A Family Of Water-Soluble, Low Molecular Weight, Nir-Emitting Fluorophores, Youjun Yang, Mark Lowry, Xiangyang Xu, Jorge O. Escobedo, Martha Sibrian-Vazquez, Lisa Wong, Corin M. Schowalter, Timothy J. Jensen, Frank R. Fronczek, Isiah M. Warner, Robert M. Strongin

Chemistry Faculty Publications and Presentations

A readily accessible new class of near infrared (NIR) molecular probes has been synthesized and evaluated. Specific fluorophores in this unique xanthene based regioisomeric seminaphthofluorone dye series exhibit a combination of desirable characteristics including (i) low molecular weight (339 amu), (ii) aqueous solubility, and (iii) dual excitation and emission from their fluorescent neutral and anionic forms. Importantly, systematic changes in the regiochemistry of benzannulation and the ionizable moieties afford (iv) tunable deep-red to NIR emission from anionic species and (v) enhanced Stokes shifts. Anionic SNAFR-6, exhibiting an unusually large Stokes …

Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis

Chemistry Faculty Publications

Chlorination and bromination reactions of thiazolo[5,4-d]thiazole led to the generation of its mono- and dihalogenated derivatives. These are the first instances of successful direct electrophilic aromatic substitution in the thiazolo[5,4-d]thiazole ring system. X-ray analysis demonstrates that both 2-bromothiazolo[5,4-d]-thiazole and 2,5-dibromothiazolo[5,4-d]thiazole are planar structures, with strongly manifested π-stacking in the solid state. Theoretical analysis of the pyridine-catalyzed halogenation (MP2/6-31+G(d) and B3LYP/6-31+G(d)calculations) reveals that introduction of one halogen actually leads to a slightly enhanced reactivity towards further halogenation. Several halogenation mechanisms have been investigated: 1) The direct C-halogenation with N-halopyridine as electrophile; …

C–N Bond Rotation And E–Z Isomerism In Some N-Benzyl-N-Methylcarbamoyl Chlorides: A Dft Study, Michael Horwath, Vladimir Benin

Chemistry Faculty Publications

The current report presents the first theoretical study of the restricted CN bond rotation in carbamoyl chlorides. Several N-benzyl-N-methylcarbamoyl chlorides were investigated, with varying pattern of substitution in the aromatic ring. Optimizations and frequency calculations were conducted employing DFT at the B3LYP/6-31+G(d) level of theory. Each of the studied structures exhibits a pair of rotamers (s-Z and s-E), generated upon rotation around the C(O)N bond. The s-E isomer is the global minimum in every case, but the preference for it is usually less than 1 kcal/mol. Two possible transition state structures were identified …

Protein Adsorption Onto Organically-Modified Silica Glass Leads To A Different Structure Than Sol-Gel Encapsulation, Daryl K. Eggers, B, Menaa, C. Torres, M. Herrero, V. Rives, A. R.W Gilbert

Faculty Publications, Chemistry

The secondary structures of two proteins were examined by circular dichroism spectroscopy after adsorption onto a series of organically modified silica glasses. The glasses were prepared by the sol-gel technique and were varied in hydrophobicity by incorporation of 5% methyl, propyl, trifluoropropyl, or n-hexyl silane. Both cytochrome c and apomyoglobin were found to lose secondary structure after adsorption onto the modified glasses. In the case of apomyoglobin, the α-helical content of the adsorbed protein ranged from 21% to 28%, well below the 62% helix found in solution. In contrast, these same glasses led to a striking increase in apomyoglobin structure …

Favourable Influence Of Hydrophobic Surfaces On Protein Structure In Porous Organically-Modified Silica Glasses, Daryl K. Eggers, B. Menaa, M. Herrero, V. Rives, M. Lavrenko

Faculty Publications, Chemistry

Organically-modified siloxanes were used as host materials to examine the influence of surface chemistry on protein conformation in a crowded environment. The sol–gel materials were prepared from tetramethoxysilane and a series of monosubstituted alkoxysilanes, RSi(OR′)3, featuring alkyl groups of increasing chain length in the R-position. Using circular dichroism spectroscopy in the far-UV region, apomyoglobin was found to transit from an unfolded state to a native-like helical state as the content of the hydrophobic precursor increased from 0 to 15%. At a fixed molar content of 5% RSi(OR′)3, the helical structure of apomyoglobin increased with the chain length of the R-group, …

Phosphorylation Of Claudin-5 And Occludin By Rho Kinase In Brain Endothelial Cells, Masaru Yamamoto, Servio H. Ramirez, Shinji Sato, Tomomi Kiyota, Ronald Cerny, Kozo Kaibuchi, Yuri Persidsky, Tsuneya Ikezu

Ronald Cerny Publications

Critical to the proper maintenance of blood-brainbarrier (BBB) integrity are the endothelial tight junctions (TJs). Posttranslational modifications of essential endothelial TJ proteins, occludin and claudin-5, contribute and possibly disrupt BBB integrity. Our previous work has shown that Rho kinase (RhoK) activation mediates occludin and claudin-5 phosphorylation resulting in diminished barrier tightness and enhanced monocyte migration across BBB in the setting of human immunodeficiency virus-1 encephalitis (HIVE). To determine whether RhoK can directly phosphorylate TJ proteins, we examined phosphorylation of cytoplasmic domains of recombinant claudin- 5 and occludin by RhoK. We found that RhoK predominately phosphorylated two sites on occludin (T382 …

Novel Photoelectrochemical Cell For The Remediation Of Organic Compounds In Water, Patrick Enright

Doctoral

Titanium dioxide (TiO2) suspensions have widely been used as photocatalysts, either alone or in a doped form to degrade organic compounds and kill bacteria. Because of its relatively large band gap, UV light has been the most efficient radiation used to allow this catalysis to occur. TiO2 has also been immobilised on electrodes in order to separate the ‘reduction’ and ‘oxidation’ reactions. Typical systems involve the oxidation of a ‘fuel’ at a TiO2 coated anode and the reduction of oxygen at a separate cathode, where the passage of current can be monitored, and this work utilises such a system. In …

Pentadienyl Complexes Of Alkali Metals: Structure And Bonding, Erick Cerpa, Francisco J. Tenorio, Maryel Contreras, Manuel Villanueva, Hiram I. Beltran, Thomas Heine, Kelling J. Donald, Gabriel Merino

Chemistry Faculty Publications

A systematic density functional study of the structure and bonding in the alkali-metal pentadienyl complexes C₅H₇E (E = Li-Cs) and their analogues derived from the 2,4-dimethylpentadienyl ligand is performed. The bonding in these structures has been analyzed in some detail with reference to molecular orbital analysis, and energy partition analysis, obtained by density functional calculations. An energy decomposition analysis indicates that the electrostatic interaction is the main factor to be considered in the stabilization of the gas-phase complexes we have studied. The stability of the U-shaped minimum energy structure decreases (the potential energy surface becomes more …

Methods In Industrial Biotechnology For Chemical Engineers, Florentin Smarandache, W.B. Vasantha Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

Industrial Biotechnology is an interdisciplinary topic to which tools of modern biotechnology are applied for finding proper proportion of raw mix of chemicals, determination of set points, finding the flow rates etc., This study is significant as it results in better economy, quality product and control of pollution. The authors in this book have given only methods of industrial biotechnology mainly to help researchers, students and chemical engineers. Since biotechnology concerns practical and diverse applications including production of new drugs, clearing up pollution etc. we have in this book given methods to control pollution in chemical industries as it has …

Phosphorylation Of Muc1 By Met Modulates Interaction With P53 And Mmp1 Expression, Pankaj K. Singh, Michelle E. Behrens, John P. Eggers, Ronald Cerny, Jennifer M. Bailey, Kandavel Shanmugam, Sandra J. Gendler, Eric P. Bennett, Michael A. Hollingsworth

Ronald Cerny Publications

MUC1, a transmembrane mucin, is a key modulator of several signaling pathways that affect oncogenesis, motility, and cell morphology. The interaction of MUC1 cytoplasmic tail (MUC1CT) with signal transducers and its nuclear translocation and subsequent biological responses are believed to be regulated by phosphorylation status, but the precise mechanisms by which this occurs remain poorly defined. We detected a novel association between the Met receptor tyrosine kinase and the MUC1CT. Met catalyzed phosphorylation of tyrosine at YHPM in the MUC1CT. Stimulation of S2-013.MUC1F pancreatic cancer cells with hepatocyte growth factor facilitated nuclear localization of MUC1CT, as determined by real time …