Biochemistry, Biophysics, and Structural Biology Commons^™

Real-Time Kinetic Studies Of Bacillus Subtilis Oxalate Decarboxylase And Ceriporiopsis Subvermispora Oxalate Oxidase Using Luminescent Oxygen Sensor, Laura Molina, Thomas Goodall, Umar Twahir, Ellen W. Moomaw

Faculty and Research Publications

Oxalate decarboxylase (OxDC), an enzyme of the bicupin superfamily, catalyzes the decomposition of oxalate into carbon dioxide and formate at an optimal pH of 4.3 in the presence of oxygen. However, about 0.2% of all reactions occur through an oxidase mechanism that consumes oxygen while producing two equivalents of carbon dioxide and one equivalent of hydrogen peroxide. The kinetics of oxidase activity were studied by measuring the consumption of dissolved oxygen over time using a luminescent oxygen sensor. We describe the implementation of and improvements to the oxygen consumption assay. The oxidase activity of wild type OxDC was compared to …

Investigating The Links Between Ozone And Organic Aerosol Chemistry In A Biomass Burning Plume From A Prescribed Fire In California Chaparral, M. J. Alvarado, C. R. Lonsdale, Robert Yokelson, S. K. Akagi, H. Coe, J. S. Craven, E. V. Fischer, G. R. Mcmeeking, J. H. Seinfeld, T. Soni, J. W. Taylor, D. R. Weise, C. E. Wold

Chemistry and Biochemistry Faculty Publications

Within minutes after emission, rapid, complex photochemistry within a biomass burning smoke plume can cause large changes in the concentrations of ozone (O₃) and organic aerosol (OA). Being able to understand and simulate this rapid chemical evolution under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use version 2.1 of the Aerosol Simulation Program (ASP) to simulate the evolution of O₃ and secondary organic aerosol (SOA) within a young biomass burning smoke plume from the Williams prescribed burn in chaparral, …

Synthesis And Characterization Of Polymer (Sulfonated Poly-Ether-Ether-Ketone) Based Nanocomposite (H-Boron Nitride) Membrane For Hydrogen Storage, Naresh Muthu, S. Rajashabala, R. Kannan

Chemistry and Biochemistry Faculty Publications

The development of light weight and compact hydrogen storage materials is still prerequisite to fuel-cell technology to be fully competitive. The present experimental study reports the hydrogen storage capability of sulfonated poly-ether-ether-ketone (SPEEK)-hexagonal boron nitride (h-BN) (SPEEK-h-BN) nanocomposite membranes. The nanocomposite membranes are prepared by considering various amount of h-BN (0, 1, 3 and 5 wt. %) by phase inversion technique. The degree of sulfonation of the PEEK (SPEEK) is found to be 65% by Proton Nuclear Magnetic Resonance (¹H NMR) spectroscopy. Hydrogen adsorption studies have been carried out using a Seiverts-like hydrogenation setup. The membranes are characterized …

Antifungal Amphiphilic Aminoglycoside K20: Bioactivities And Mechanism Of Action, Sanjib K. Shrestha, Cheng-Wei Tom Chang, Nicole Meissner, John Oblad, Jaya P. Shrestha, Kevin N. Sorensen, Michelle M. Grilley, Jon Y. Takemoto

Chemistry and Biochemistry Faculty Publications

K20 is a novel amphiphilic antifungal aminoglycoside that is synthetically derived from the antibiotic kanamycin A. Reported here are investigations of K20′s antimicrobial activities, cytotoxicity, and fungicidal mechanism of action. In vitro growth inhibitory activities against a variety of human and plant pathogenic yeasts, filamentous fungi, and bacteria were determined using microbroth dilution assays and time-kill curve analyses, and hemolytic and animal cell cytotoxic activities were determined. Effects on Cryptococcus neoformans H-99 infectivity were determined with a preventive murine lung infection model. The antifungal mechanism of action was studied using intact fungal cells, yeast lipid mutants, and small unilamellar lipid …

Odd-Even Effects In Charge Transport Across N-Alkanethiolate-Based Sams, Mostafa Baghbanzadeh, Felice C. Simeone, Carleen M. Bowers, Kung Ching Liao, Martin Thuo, Mahdi Baghbanzadeh, Michael S. Miller, Tricia Breen Carmichael, George M. Whitesides

Chemistry and Biochemistry Publications

This paper compares rates of charge transport across self-assembled monolayers (SAMs) of n-alkanethiolates having odd and even numbers of carbon atoms (nodd and neven) using junctions with the structure MTS/SAM//Ga2O3/EGaIn (M = Au or Ag). Measurements of current density, J(V), across SAMs of n-alkanethiolates on AuTS and AgTS demonstrated a statistically significant odd-even effect on AuTS, but not on AgTS, that could be detected using this technique. Statistical analysis showed the values of tunneling current density across SAMs of n-alkanethiolates on AuTS with nodd and neven belonging to two separate sets, and while there is a significant difference between the …

Ultrasmooth Gold Surfaces Prepared By Chemical Mechanical Polishing For Applications In Nanoscience, Michael S. Miller, Michael Anthony Ferrato, Adrian Niec, Mark C. Biesinger, Tricia Breen Carmichael

Chemistry and Biochemistry Publications

For over 20 years, template stripping has been the best method for preparing ultrasmooth metal surfaces for studies of nanostructures. However, the organic adhesives used in the template stripping method are incompatible with many solvents, limiting the conditions that may subsequently be used to prepare samples; in addition, the film areas that can be reliably prepared are typically limited to ∼1 cm2. In this article, we present chemical-mechanical polishing (CMP) as an adhesive-free, scalable method of preparing ultrasmooth gold surfaces. In this process, a gold film is first deposited by e-beam evaporation onto a 76-mm-diameter silicon wafer. The CMP process …

A 5', 8-Cyclo-2'-Deoxypurine Lesion Induces Trinucleotide Repeat Deletion Via A Unique Lesion Bypass By Dna Polymerase Β., Meng Xu, Yanhao Lai, Zhongliang Jiang, Michael A. Terzidis, Annalisa Masi, Chryssostomos Chatgilialoglu, Yuan Liu

Department of Chemistry and Biochemistry

5′,8-cyclo-2′-deoxypurines (cdPus) are common forms of oxidized DNA lesions resulting from endogenous and environmental oxidative stress such as ionizing radiation. The lesions can only be repaired by nucleotide excision repair with a low efficiency. This results in their accumulation in the genome that leads to stalling of the replication DNA polymerases and poor lesion bypass by translesion DNA polymerases. Trinucleotide repeats (TNRs) consist of tandem repeats of Gs and As and therefore are hotspots of cdPus. In this study, we provided the first evidence that both (5′R)- and (5′S)-5′,8-cyclo-2′-deoxyadenosine (cdA) in a CAG repeat tract caused CTG repeat deletion exclusively …

The Development Of A Valid And Reliable Biogeochemistry Concept Inventory, Chris Mead

DBER Speaker Series

Concept inventories are a commonly used tool to measure conceptual understanding. To date, concept inventories have been published for geology, chemistry, and biology, but no instrument has been designed to measure conceptual understanding at the intersection of those fields. To fill that gap, we constructed a 32‐item biogeochemistry concept inventory (BGC‐CI). Item response theory analysis, using the Rasch model, shows the BGC‐CI is a reliable and valid tool to measure the biogeochemistry knowledge of science majors. Because biogeochemistry is an interdisciplinary field, we were concerned about the unidimensionality of the instrument. However, our analysis showed the BGC‐CI to be acceptably …

Cold Magnetically Trapped 2DG Scandium Atoms. I. Interaction Potential, Tijs Karman, Xi Chu, Gerrit C. Groenenboom

Chemistry and Biochemistry Faculty Publications

We present a first principles description of the interaction of two ground-state scandium atoms. Scandium has a ²D_g ground state. Thirty molecular states correlate to the lowest dissociation limit of the dimer. In the short range, potential energy curves are calculated using second-order n-electron valence state perturbation theory. The first-order long-range interaction is calculated at the complete active space self-consistent field level. We determine the second-order long-range dispersion interaction from atomic dynamic polarizabilities at imaginary frequencies. These polarizabilities are calculated using time-dependent density functional theory. We merge the short-range approach with the long-range model to obtain a physical …

Cross-Disciplinary Sciences At Gettysburg College: Second Annual Poster Presentation, X-Sig

Student Publications

This booklet includes Biology student presentations by: Taylor Bury, Abigail Dworkin-Brodsky, Mary Pearce, Jasper Leavitt, Morgan Panzer, Ellen Petley, Kalli Qutub, Taylor Randell, Samantha Eck, Lana McDowell, Jenn Soroka, Celina Harris, Natalie Tanke, Alexandra Turano, and Caroline Garliss.

This booklet includes Biochemistry & Molecular Biology student presentations by: Matthew Dunworth, Andrew Sydenstricker, Brianne Tomko, Albert Vill, Warren Campbell, David Van Doren, Kevin Mrugalski, Stacey Heaver, Alecia Achimovich, and Katherine Boas.

This booklet includes Chemistry student presentations by: Kristen Baker, Laura Lee, Kathryn Fodale, Daniel Ruff, Michael Counihan, Ida DiMucci, Joshua Sgroi, Celina Harris, and Natalie Tanke.

This booklet include Health …

Aerosol Emissions From Prescribed Fires In The United States: A Synthesis Of Laboratory And Aircraft Measurements, A. A. May, G. R. Mcmeeking, T. Lee, J. W. Taylor, J. S. Craven, I. R. Burling, A. P. Sullivan, Sheryl Kashi Akagi, J. L. Collett Jr., M. Flynn, H. Coe, S. P. Urbanski, J. H. Seinfeld, Robert Yokelson, S. M. Kreidenweis

Chemistry and Biochemistry Faculty Publications

Aerosol emissions from prescribed fires can affect air quality on regional scales. Accurate representation of these emissions in models requires information regarding the amount and composition of the emitted species.Wemeasured a suite of submicron particulatematter species in young plumes emitted from prescribed fires (chaparral and montane ecosystems in California; coastal plain ecosystem in South Carolina) and from open burning of over 15 individual plant species in the laboratory. We report emission ratios and emission factors for refractory black carbon (rBC) and submicron nonrefractory aerosol and compare field and laboratory measurements to assess the representativeness of our laboratory-measured emissions. Laboratory measurements …

Activated Cyclopropanes: A Remarkable Breadth Of Recent Chemistry, James R. Green, Victor Snieckus

Chemistry and Biochemistry Publications

The reactions of cyclopropanes activated by electron-withdrawing groups and electron-donating groups – donor–acceptor (DA) cyclopropanes – and with alkenyl or alkylidene substituents has been an area of recent intense research activity. This Cluster contains contributions from many of the leading research groups in this area, and provides a concise introduction to the rich ring-opening, ring-expansion, dimerization, and cycloaddition chemistry of these compounds.

Synthesis Of Tenuifolin Via Intramolecular Nicholas Reaction, Sinisa Djurdjevic, James R. Green

Chemistry and Biochemistry Publications

The synthesis of the Cinnamomum homosesquiterpenoid tenuifolin has been accomplished by way of an intramolecular Nicholas reaction of the [Co₂(CO)₆] complex of an alkyne-substituted biaryl for construction of the seven-membered ring. The cyclization features the reaction of a nonactivated arene ring with the propargyldicobalt cation to give the dibenzocycloheptyne-Co₂(CO)₆.

The Potential Of Quinoline Derivatives For The Treatment Of Toxoplasma Gondii Infection., Sirinart Ananvoranich

Chemistry and Biochemistry Publications

Here we reported our investigation, as part of our drug repositioning effort, on anti-Toxoplasma properties of newly synthesized quinoline compounds. A collection of 4-aminoquinoline and 4-piperazinylquinoline analogs have recently been synthesized for use in cancer chemotherapy. Some analogs were able to outperform chloroquine, a quinoline derivative drug which is commonly used in the treatment of malaria and other parasitic infections. Herein 58 compounds containing one or two quinoline rings were examined for their effectiveness as potential anti-Toxoplasma compounds. Of these 58 compounds, 32 were efficient at inhibiting Toxoplasma growth (IC50μM). Five compounds with single and simple quinoline rings exhibited similar …

Airborne Characterization Of Smoke Marker Ratios From Prescribed Burning, A. P. Sullivan, A. A. May, T. Lee, G. R. Mcmeeking, S. M. Kreidenweis, S. K. Akagi, Robert Yokelson, S. P. Urbanski, J. L. Collett Jr.

Chemistry and Biochemistry Faculty Publications

A Particle-Into-Liquid Sampler – Total Organic Carbon (PILS-TOC) and fraction collector system was flown aboard a Twin Otter aircraft sampling prescribed burning emissions in South Carolina in November 2011 to obtain smoke marker measurements. The fraction collector provided 2 min time-integrated offline samples for carbohydrate (i.e., smoke markers levoglucosan, mannosan, and galactosan) analysis by high-performance anion-exchange chromatography with pulsed amperometric detection. Each fire location appeared to have a unique 1levoglucosan /1water-soluble organic carbon (WSOC) ratio (RF01/RF02/RF03/RF05 = 0.163± 0.007 μg C μg−1 C, RF08 = 0.115 ± 0.011 μg C μg−1 C, RF09A = 0.072 ± 0.028 μgC μg−1 C, …

Trace Gas Emissions From Combustion Of Peat, Crop Residue, Domestic Biofuels, Grasses, And Other Fuels: Configuration And Fourier Transform Infrared (Ftir) Component Of The Fourth Fire Lab At Missoula Experiment (Flame-4), C. E. Stockwell, R. J. Yokelson, S. M. Kreidenweis, A. L. Robinson, P. J. Demott, R. C. Sullivan, J. Reardon, K. C. Ryan, D. W.T. Griffith, L. Stevens

Chemistry and Biochemistry Faculty Publications

During the fourth Fire Lab at Missoula Experiment (FLAME-4, October-November 2012) a large variety of regionally and globally significant biomass fuels was burned at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particle emissions were characterized by an extensive suite of instrumentation that measured aerosol chemistry, size distribution, optical properties, and cloud-nucleating properties. The trace gas measurements included high-resolution mass spectrometry, one-and two-dimensional gas chromatography, and open-path Fourier transform infrared (OP-FTIR) spectroscopy. This paper summarizes the overall experimental design for FLAME-4-including the fuel properties, the nature of the burn simulations, and the instrumentation employed-and then focuses on …

Identification And Quantification Of Gaseous Organic Compounds Emitted From Biomass Burning Using Two-Dimensional Gas Chromatography/Time-Of-Flight Mass Spectrometry, L. E. Hatch, W. Luo, J. F. Pankow, Robert Yokelson, C. Stockwell, K. C. Barsanti

Chemistry and Biochemistry Faculty Publications

The current understanding of secondary organic aerosol (SOA) formation within biomass burning (BB) plumes is limited by the incomplete identification and quantification of the non-methane organic compounds (NMOCs) emitted from such fires. Gaseous organic compounds were collected on sorbent cartridges during laboratory burns as part of the fourth Fire Lab at Missoula Experiment (FLAME-4), with analysis by two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC/TOFMS). The sensitivity and resolving power of GC×GC/TOFMS allowed the acquisition of the most extensive data set of BB NMOCs to date, with measure ments for 722 positively or tentatively identified compounds. Estimated emission factors (EFs) are presented …

A Multi-Scale Computational Study On The Mechanism Of Streptococcus Pneumoniae Nicotinamidase (Spnic), Bogdan F. Ion, Erum Kazim, James Gauld

Chemistry and Biochemistry Publications

Nicotinamidase (Nic) is a key zinc-dependent enzyme in NAD metabolism that catalyzes the hydrolysis of nicotinamide to give nicotinic acid. A multi-scale computational approach has been used to investigate the catalytic mechanism, substrate binding and roles of active site residues of Nic from Streptococcus pneumoniae (SpNic). In particular, density functional theory (DFT), molecular dynamics (MD) and ONIOM quantum mechanics/molecular mechanics (QM/MM) methods have been employed. The overall mechanism occurs in two stages: (i) formation of a thioester enzyme-intermediate (IC2) and (ii) hydrolysis of the thioester bond to give the products. The polar protein environment has a significant effect in stabilizing …

Bio-Compatible Polymer Coatings Using Low Temperature, Atmospheric Pressure Plasma, Susan Farhat, Mary Gilliam, Ali Zand, Montserrat Rabago-Smith

Chemistry & Biochemistry Presentations And Conference Materials

Current research has been dedicated to investigating the viability of atmospheric pressure plasmas for use in coating technology. In addition to being more cost effective and efficient, atmospheric pressure plasma offers a more streamlined process, as it can be employed directly into the production line. Atmospheric pressure plasma has been used in applications including biocompatibility, hydrophilicity/hydrophobicity, and coating with antibacterial films. Polyethylene is used as a biocompatible surface for ball and socket joint replacements, which are under constant wear. Atmospheric pressure plasma treatment was used to change the surface chemistry by grafting various biocompatible polymers to the polyethylene surface, as …

The Evolution Of Respiratory O2/No Reductases: An Out-Of-The-Phylogenetic-Box Perspective, Anne-Lise Ducluzeau, Barbara Schoepp-Cothenet, Robert Van Lis, Frauke Baymann, Michael J. Russell, Wilfgang Nitschke

Department of Biochemistry: Faculty Publications

Complex life on our planet crucially depends on strong redox disequilibria afforded by the almost ubiquitous presence of highly oxidizing molecular oxygen. However, the history of O₂-levels in the atmosphere is complex and prior to the Great Oxidation Event some 2.3 billion years ago, the amount of O₂ in the biosphere is considered to have been extremely low as compared with present-day values. Therefore the evolutionary histories of life and of O₂-levels are likely intricately intertwined. The obvious biological proxy for inferring the impact of changing O₂-levels on life is the evolutionary history …

Implications Of The Landauer Limit For Quantum Logic, F. Matthew Mihelic

Faculty Publications

The design of any system of quantum logic must take into account the implications of the Landauer limit for logical bits. Useful computation implies a deterministic outcome, and so any system of quantum computation must produce a final deterministic outcome, which in a quantum computer requires a quantum decision that produces a deterministic qubit. All information is physical, and any bit of information can be considered to exist in a physicality represented as a decision between the two wells of a double well potential in which the energy barrier between the two wells must be greater than kT·ln2. Any proposed …

Reclaiming The Efficacy Of Β-Lactam–Β-Lactamase Inhibitor Combinations: Avibactam Restores The Susceptibility Of Cmy-2-Producing Escherichia Coli To Ceftazidime, Krisztina M. Papp-Wallace, Marisa L. Winkler, Julian A. Gatta, Magdalena A. Taracila, Sujatha Chilakala, Yan Xu, J. Kristie Johnson, Robert A. Bonomo

Chemistry Faculty Publications

CMY-2 is a plasmid-encoded Ambler class C cephalosporinase that is widely disseminated in Enterobacteriaceae and is responsible for expanded-spectrum cephalosporin resistance. As a result of resistance to both ceftazidime and β-lactamase inhibitors in strains carrying blaCMY, novel β-lactam–β-lactamase inhibitor combinations are sought to combat this significant threat to β-lactam therapy. Avibactam is a bridged diazabicyclo [3.2.1]octanone non-β-lactam β-lactamase inhibitor in clinical development that reversibly inactivates serine β-lactamases. To define the spectrum of activity of ceftazidime-avibactam, we tested the susceptibilities of Escherichia coli clinical isolates that carry blaCMY-2 or blaCMY-69 and investigated the inactivation kinetics of CMY-2. Our analysis showed that …

2-Acylamido Analogues Of N-Acetylglucosamine Prime Formation Of Chitin Oligosaccharides By Yeast Chitin Synthase 2, Jacob Gyore, Archana Parameswar, Carleigh Hebbard, Younghoon Oh, Erfei Bi, Alexei Demchenko, Neil Price, Peter Orlean

Chemistry & Biochemistry Faculty Works

Chitin, a homopolymer of β1,4-linked N-acetylglucosamine (GlcNAc) residues, is a key component of the cell walls of fungi and the exoskeletons of arthropods. Chitin synthases transfer GlcNAc from UDP-GlcNAc to preexisting chitin chains in reactions that are typically stimulated by free GlcNAc. The effect of GlcNAc was probed by using a yeast strain expressing a single chitin synthase, Chs2, by examining formation of chitin oligosaccharides (COs) and insoluble chitin, and by replacing GlcNAc with 2-acylamido analogues of GlcNAc. Synthesis of COs was strongly dependent on inclusion of GlcNAc in chitin synthase incubations, and N,N′-diacetylchitobiose (GlcNAc2) was the major reaction product. …

Metal Stopping Reagents Facilitate Discontinuous Activity Assays Of The De Novo Purine Biosynthesis Enzyme Pure, Kelly L. Sullivan, Loredana C. Huma, Elwood Mullins, Michael E. Johnson, T. Joseph Kappock

Department of Biochemistry Faculty Publications

The conversion of 5-aminoimidazole ribonucleotide (AIR) to 4-carboxy-AIR (CAIR) represents an unusual divergence in purine biosynthesis: microbes and nonmetazoan eukaryotes use class I PurEs while animals use class II PurEs. Class I PurEs are therefore a potential antimicrobial target; however, no enzyme activity assay is suitable for high throughput screening (HTS). Here we report a simple chemical quench that fixes the PurE substrate/product ratio for 24 h, as assessed by the Bratton-Marshall assay (BMA) for diazotizable amines. The ZnSO₄ stopping reagent is proposed to chelate CAIR, enabling delayed analysis of this acid-labile product by BMA or other HTS methods

Redox Active Motifs In Selenoproteins, Fei Li, Yuliya Pepelyayeva, Elias S. J. Arner, Craig A. Bayse, Sharon Rozovsky

Chemistry & Biochemistry Faculty Publications

Selenoproteins use the rare amino acid selenocysteine (Sec) to act as the first line of defense against oxidants, which are linked to aging, cancer, and neurodegenerative diseases. Many selenoproteins are oxidoreductases in which the reactive Sec is connected to a neighboring Cys and able to form a ring. These Sec-containing redox motifs govern much of the reactivity of selenoproteins. To study their fundamental properties, we have used Se-77 NMR spectroscopy in concert with theoretical calculations to determine the conformational preferences and mobility of representative motifs. This use of Se-77 as a probe enables the direct recording of the properties of …

Antimicrobial And Antiinsectan Phenolic Metabolites Of Dalea Searlsiae, Gil Belofsky, Mario Aronica, Eric Foss, Jane Diamond, Felipe Santana, Jacob Darley, Patrick F. Dowd, Christina M. Coleman, Daneel Ferreira

All Faculty Scholarship for the College of the Sciences

Continued interest in the chemistry of Dalea spp. led to investigation of Dalea searlsiae, a plant native to areas of the western United States. Methanol extractions of D. searlsiae roots and subsequent chromatographic fractionation afforded the new prenylated and geranylated flavanones malheurans A–D (1–4) and known flavanones (5 and 6). Known rotenoids (7 and 8) and isoflavones (9 and 10) were isolated from aerial portions. Structure determination of pure compounds was accomplished primarily by extensive 1D- and 2D-NMR spectroscopy. The absolute configurations of compounds 1–5, 7 …

Base Excision Repair Of Chemotherapeutically-Induced Alkylated Dna Damage Predominantly Causes Contractions Of Expanded Gaa Repeats Associated With Friedreich's Ataxia, Yanhao Lai, Jill M. Beaver, Karla Lorente, Jonathan Melo, Shyama Ramjagsingh, Irina U. Agoulnik, Zunzhen Zhang, Yuan Liu

Department of Chemistry and Biochemistry

Expansion of GAA·TTC repeats within the first intron of the frataxin gene is the cause of Friedreich's ataxia (FRDA), an autosomal recessive neurodegenerative disorder. However, no effective treatment for the disease has been developed as yet. In this study, we explored a possibility of shortening expanded GAA repeats associated with FRDA through chemotherapeutically-induced DNA base lesions and subsequent base excision repair (BER). We provide the first evidence that alkylated DNA damage induced by temozolomide, a chemotherapeutic DNA damaging agent can induce massive GAA repeat contractions/deletions, but only limited expansions in FRDA patient lymphoblasts. We showed that temozolomide-induced GAA repeat instability …

Conformational Dynamics Associated With Ligand Binding To Vertebrate Hexa-Coordinate Hemoglobins, Luisana Astudillo

FIU Electronic Theses and Dissertations

Neuroglobin (Ngb) and cytoglobin (Cygb) are two new additions to the globin family, exhibiting heme iron hexa-coordination, a disulfide bond and large internal cavities. These proteins are implicated in cytoprotection under hypoxic-ischemic conditions, but the molecular basis of their cytoprotective function is unclear.

Herein, a photothermal and spectroscopic study of the interactions of diatomic ligands with Ngb, Cygb, myoglobin and hemoglobin is presented. The impact of the disulfide bond in Ngb and Cygb and role of conserved residues in Ngb His64, Val68, Cys55, Cys120 and Tyr44 on conformational dynamics associated with ligand binding/dissociation were investigated. Transient absorption and photoacoustic calorimetry …

Structural Insights Into The Interaction Between A Potent Anti-Inflammatory Protein, Viral Cc Chemokine Inhibitor (Vcci), And The Human Cc Chemokine, Eotaxin-1, Nai-Wei Kuo, Yong-Guang Gao, Megan Schill, Nancy Isern, Cynthia Dupureur, Patricia Liwang

Chemistry & Biochemistry Faculty Works

Chemokines play important roles in the immune system, not only recruiting leukocytes to the site of infection and inflammation but also guiding cell homing and cell development. The soluble poxvirus-encoded protein viral CC chemokine inhibitor (vCCI), a CC chemokine inhibitor, can bind to human CC chemokines tightly to impair the host immune defense. This protein has no known homologs in eukaryotes and may represent a potent method to stop inflammation. Previously, our structure of the vCCI·MIP-1β (macrophage inflammatory protein-1β) complex indicated that vCCI uses negatively charged residues in β-sheet II to interact with positively charged residues in the MIP-1β N …

Helical ∞ 1[Pb2o] Chains In Polymorphs Of Pb2o(C6h5coo)2, Clay C. Easterday, Liv R. Dedon, Matthias Zeller, Catherine M. Oertel

Faculty & Staff Scholarship

Three new lead oxide benzoates have been prepared solvothermally. In two polymorphs, 1 and 2, of Pb2O(C6H5COO)2, distorted Pb4O tetrahedra share edges to form helical ∞1[Pb2O] chains. Unprecedented among Pb4O-based structures, these motifs may be viewed as double helices of lead atoms surrounding the central oxygen atoms. Both right- and left-handed helices are included in each structure. Formation of the polymorphs was controlled through variation in synthetic conditions. Polymorph 1 crystallizes in the achiral, polar space group Fdd2. Polymorph 2, in P21, is a rare example of a kryptoracemate in which crystallographically independent chains of both chiralities occur in the …