Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 42

Full-Text Articles in Physical Sciences and Mathematics

Inhibitors Of -Acetyl-L-Ornithine Deacetylase: Synthesis, Characterization And Analysis Of Their Inhibitory Potency, J. Hlavacek, J. Picha, V. Vanek, J. Jiracek, J. Slaninova, V. Fucik, M. Budesinsky, Danuta Gillner, Richard Holz Dec 2014

Inhibitors Of Nα-Acetyl-L-Ornithine Deacetylase: Synthesis, Characterization And Analysis Of Their Inhibitory Potency, J. Hlavacek, J. Picha, V. Vanek, J. Jiracek, J. Slaninova, V. Fucik, M. Budesinsky, Danuta Gillner, Richard Holz

Richard C. Holz

A series of N α-acyl (alkyl)- and N α-alkoxycarbonyl-derivatives of l- and d-ornithine were prepared, characterized, and analyzed for their potency toward the bacterial enzyme N α-acetyl-l-ornithine deacetylase (ArgE). ArgE catalyzes the conversion of N α-acetyl-l-ornithine to l-ornithine in the fifth step of the biosynthetic pathway for arginine, a necessary step for bacterial growth. Most of the compounds tested provided IC50 values in the μM range toward ArgE, indicating that they are moderately strong inhibitors. N α-chloroacetyl-l-ornithine (1g) was the best inhibitor tested toward ArgE providing an IC50 value of 85 μM while N α-trifluoroacetyl-l-ornithine (1f), N α-ethoxycarbonyl-l-ornithine (2b), and …


Immobilization Of The Aminopeptidase From Aeromonas Proteolytica On Mg2+/Al3+ Layered Double Hydroxide Particles, Steven Frey, Stephanie Guilmet, Richard Egan, Alyssa Bennett, Sarah Soltau, Richard Holz Dec 2014

Immobilization Of The Aminopeptidase From Aeromonas Proteolytica On Mg2+/Al3+ Layered Double Hydroxide Particles, Steven Frey, Stephanie Guilmet, Richard Egan, Alyssa Bennett, Sarah Soltau, Richard Holz

Richard C. Holz

A novel biomaterial formed by the immobilization of the Aminopeptidase from Aeromonas proteolytica (AAP) on synthetic Mg2+ and Al3+ ion-containing layered double hydroxide (LDH) particles was prepared. Immobilization of AAP on the LDH particles in a buffered, aqueous mixture is rapid such that the maximum loading capacity, 1 × 10−9 moles of AAP/mg LDH, is achieved in a few minutes. X-ray powder diffraction of LDH samples before and after treatment with AAP indicates that the enzyme does not intercalate between the layers of LDH, but instead binds to the surface. Treatment of AAP/LDH with various amounts of salt in a …


Analyzing The Binding Of Co(Ii)-Specific Inhibitors To The Methionyl Aminopeptidases From Escherichia Coli And Pyrococcus Furiosus, Sanghamitra Mitra, George Sheppard, Jieyi Wang, Brian Bennett, Richard Holz Dec 2014

Analyzing The Binding Of Co(Ii)-Specific Inhibitors To The Methionyl Aminopeptidases From Escherichia Coli And Pyrococcus Furiosus, Sanghamitra Mitra, George Sheppard, Jieyi Wang, Brian Bennett, Richard Holz

Richard C. Holz

Methionine aminopeptidases (MetAPs) represent a unique class of protease that is capable of the hydrolytic removal of an N-terminal methionine residue from nascent polypeptide chains. MetAPs are physiologically important enzymes; hence, there is considerable interest in developing inhibitors that can be used as antiangiogenic and antimicrobial agents. A detailed kinetic and spectroscopic study has been performed to probe the binding of a triazole-based inhibitor and a bestatin-based inhibitor to both Mn(II)- and Co(II)-loaded type-I (Escherichia coli) and type-II (Pyrococcus furiosus) MetAPs. Both inhibitors were found to be moderate competitive inhibitors. The triazole-type inhibitor was found to …


Direct Patterning Of Silanized-Biomolecules On Semiconductor Surfaces, Dorjderem Nyamjav, Richard Holz Dec 2014

Direct Patterning Of Silanized-Biomolecules On Semiconductor Surfaces, Dorjderem Nyamjav, Richard Holz

Richard C. Holz

A novel approach to pattern silanized-biomolecules directly onto glass (SiOx) substrates via Dip-Pen nanolithography (DPN) and microcontact printing (μCP) is presented. Subsequent hybridization reactions of DPN patterned silanized-DNA with its complementary strands provide “proof-of-concept” that the patterned oligonucleotides maintain their biological activities. The fabrication strategy does not require premodification of substrates and offers a cheap and robust way to immobilize molecules on electronically important semiconductor surfaces.


Direct Patterning Of A Cyclotriveratrylene Derivative For Directed Self-Assembly Of C60, Zachary Osner, Dorjderem Nyamjav, Richard Holz, Daniel Becker Dec 2014

Direct Patterning Of A Cyclotriveratrylene Derivative For Directed Self-Assembly Of C60, Zachary Osner, Dorjderem Nyamjav, Richard Holz, Daniel Becker

Richard C. Holz

A novel apex-modified cyclotriveratrylene (CTV) derivative with an attached thiolane-containing lipoic acid linker was directly patterned onto gold substrates via dip-pen nanolithography (DPN). The addition of a dithiolane-containing linker to the apex of CTV provides a molecule that can adhere to a gold surface with its bowl-shaped cavity directed away from the surface, thereby providing a surface-bound CTV host that can be used for the directed assembly of guest molecules. Subsequent exposure of these CTV microarrays to C60 in toluene resulted in the directed assembly of predesigned, spatially controlled, high-density microarrays of C60. The molecular recognition capabilities of this CTV …


Structural Basis For Catalysis By The Mono- And Dimetalated Forms Of The Dape-Encoded N-Succinyl-L,L-Diaminopimelic Acid Desuccinylase, Boguslaw Nocek, Danuta Gillner, Yao Fan, Richard Holz, Andzrej Joachimiak Dec 2014

Structural Basis For Catalysis By The Mono- And Dimetalated Forms Of The Dape-Encoded N-Succinyl-L,L-Diaminopimelic Acid Desuccinylase, Boguslaw Nocek, Danuta Gillner, Yao Fan, Richard Holz, Andzrej Joachimiak

Richard C. Holz

Biosynthesis of lysine and meso-diaminopimelic acid in bacteria provides essential components for protein synthesis and construction of the bacterial peptidoglycan cell wall. The dapE operon enzymes synthesize both meso-diaminopimelic acid and lysine and, therefore, represent potential targets for novel antibacterials. The dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase functions in a late step of the pathway and converts N-succinyl-l,l-diaminopimelic acid to l,l-diaminopimelic acid and succinate. Deletion of the dapE gene is lethal to Helicobacter pylori and Mycobacterium smegmatis, indicating that DapE's are essential for cell growth and proliferation. Since there are no similar pathways in humans, inhibitors …


Inhibitors Of Bacterial N-Succinyl-L,L-Diaminopimelic Acid Desuccinylase (Dape) And Demonstration Of In Vitro Antimicrobial Activity, Danuta Gillner, Nicola Armoush, Richard Holz, Daniel Becker Dec 2014

Inhibitors Of Bacterial N-Succinyl-L,L-Diaminopimelic Acid Desuccinylase (Dape) And Demonstration Of In Vitro Antimicrobial Activity, Danuta Gillner, Nicola Armoush, Richard Holz, Daniel Becker

Richard C. Holz

The dapE-encoded N-succinyl-L,L-diaminopimelic acid desuccinylase (DapE) is a critical bacterial enzyme for the construction of the bacterial cell wall. A screen biased toward compounds containing zinc-binding groups (ZBG’s) including thiols, carboxylic acids, boronic acids, phosphonates and hydroxamates has delivered a number of micromolar inhibitors of DapE from Haemophilus influenzae, including the low micromolar inhibitor L-captopril (IC50 = 3.3 μM, Ki = 1.8 μM). In vitro antimicrobial activity was demonstrated for l-captopril against Escherichia coli.


The Fe-Type Nitrile Hydratase From Comamonas Testosteroni Ni1 Does Not Require An Activator Accessory Protein For Expression In Escherichia Coli, Misty Kuhn, Salette Martinez, Natalie Gumataotao, Uwe Bornscheuer, Dali Liu, Richard Holz Dec 2014

The Fe-Type Nitrile Hydratase From Comamonas Testosteroni Ni1 Does Not Require An Activator Accessory Protein For Expression In Escherichia Coli, Misty Kuhn, Salette Martinez, Natalie Gumataotao, Uwe Bornscheuer, Dali Liu, Richard Holz

Richard C. Holz

We report herein the functional expression of an Fe-type nitrile hydratase (NHase) without the co-expression of an activator protein or the Escherichia coli chaperone proteins GroES/EL. Soluble protein was obtained when the α- and β-subunit genes of the Fe-type NHase Comamonas testosteroni Ni1 (CtNHase) were synthesized with optimized E. coli codon usage and co-expressed. As a control, the Fe-type NHase from Rhodococcus equi TG328–2 (ReNHase) was expressed with (ReNHase+Act) and without (ReNHase−Act) its activator protein, establishing that expression of a fully functional, metallated ReNHase enzyme requires the co-expression of its activator protein, similar to all other Fe-type NHase enzymes reported …


Immobilization Of Motile Bacterial Cells Via Dip-Pen Nanolithography, Dorjderem Nyamjav, Sergey Rozhok, Richard Holz Dec 2014

Immobilization Of Motile Bacterial Cells Via Dip-Pen Nanolithography, Dorjderem Nyamjav, Sergey Rozhok, Richard Holz

Richard C. Holz

A strategy to bind bacterial cells to surfaces in a directed fashion via dip-pen nanolithography (DPN) is presented. Cellular attachment to pre-designed DPN generated microarrays was found to be dependent on the shape and size of the surface feature. While this observation is likely due in part to a dense, well formed mercaptohexadecanoic acid (MHA) monolayer generated via DPN, it may also simply be due to the physical shape of the surface structure. Motile Pseudomonas aeruginosa bacterial cells were observed to bind to DPN generated mercaptohexadecanoic acid/poly-L-lysine (MHA/PLL) line patterns, 'blocks' made up of eight lines with 100 nm spacings, …


Structural Characterization Of Zn(Ii)-, Co(Ii)-, And Mn(Ii)-Loaded Forms Of The Arge-Encoded N-Acetyl-L-Ornithine Deacetylase From Escherichia Coli, Ye Tao, Jacob Shokes, Wade Mcgregor, Robert Scott, Richard Holz Dec 2014

Structural Characterization Of Zn(Ii)-, Co(Ii)-, And Mn(Ii)-Loaded Forms Of The Arge-Encoded N-Acetyl-L-Ornithine Deacetylase From Escherichia Coli, Ye Tao, Jacob Shokes, Wade Mcgregor, Robert Scott, Richard Holz

Richard C. Holz

The Zn, Co, and Mn K-edge extended X-ray absorption fine structure (EXAFS) spectra of the N-acetyl-l-ornithine deacetylase (ArgE) from Escherichia coli, loaded with one or two equivalents of divalent metal ions (i.e., [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)], [Co(II)Co(II)(ArgE)], [Mn(II)_(ArgE)], and [Mn(II)Mn(II)(ArgE)]), were recorded. The Fourier transformed data (FT) for [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)] and [Co(II)Co(II)(ArgE)] are dominated by a peak at 2.05 Å, that can be fit assuming five or six light atom (N,O) scatterers. Inclusion of multiple-scattering contributions from the outer-shell atoms of a histidine-imidazole ring resulted in reasonable Debye–Waller factors for these contributions and a slight reduction in the goodness-of-fit value …


Synthesis Of N-Succinyl-L,L-Diaminopimelic Acid Mimetics Via Selective Protection, V. Vanek, J. Picha, M. Budesinsky, M. Sanda, J. Jiracek, Richard Holz, J. Hlavacek Dec 2014

Synthesis Of N-Succinyl-L,L-Diaminopimelic Acid Mimetics Via Selective Protection, V. Vanek, J. Picha, M. Budesinsky, M. Sanda, J. Jiracek, Richard Holz, J. Hlavacek

Richard C. Holz

The search for potential inhibitors that target so far unexplored bacterial enzyme mono-N-succinyl-L,Ldiaminopimelic acid desuccinylase (DapE) has stimulated a development of methodology for quick and efficient preparation of mono-N-acylated 2,6-diaminopimelic acid (DAP) derivatives bearing the different carboxyl groups or lipophilic moieties on their amino group.


Amphipathic Co-Oligomers For The Delivery Of Sirna, Christina Cooley, Erika Geihe, Robert Waymouth, Paul Wender Nov 2014

Amphipathic Co-Oligomers For The Delivery Of Sirna, Christina Cooley, Erika Geihe, Robert Waymouth, Paul Wender

Christina B Cooley

Co-oligomer compounds, complexes of the same with polyanions, such as siRNAs, and methods for using the same are provided. the delivery of polynucleotides, into a cell. The subject co-oligomers include at least a liphopilic monomer and at least a hydrophilic monomer (e.g., a guanidinium containing monomer). In some embodiments, the co-oligomer compounds are capable of complexing a siRNA of interest, thereby increasing the cell permeability of the siRNA, prior to release of the siRNA into the cell. In some embodiments, the subject method is a method of delivery a siRNA into a cell. In some embodiments, the subject method is …


Magnetic Properties Of (Γ-Fe₂O₃)₈₀Ag₂₀ Nanocomposites Prepared In Reverse Micelles, Joan Wiemann, Jianbiao Dai, Jinke Tang, Gary Long, Leonard Spinu Oct 2014

Magnetic Properties Of (Γ-Fe₂O₃)₈₀Ag₂₀ Nanocomposites Prepared In Reverse Micelles, Joan Wiemann, Jianbiao Dai, Jinke Tang, Gary Long, Leonard Spinu

Jinke Tang

The magnetic properties of nanoparticles of γ-Fe2O3 prepared by reverse micelles have been studied by dc magnetization, transverse ac susceptibility, and Mössbauer spectroscopy. The nanoparticles of γ-Fe2O3 in the nanocomposite (γ- Fe2 O3) 80Ag20 exhibit superparamagnetic behavior. The blocking temperatures determined by the three methods indicate the superparamagnetic nature of (γ- Fe2 O3) 80Ag20 above 70-80 K and show correlation with measuring time. The average particle diameter obtained by transmission electron microscopy of the γ-Fe2O3 particles is 10 nm and that of the Ag particles is 20 nm. The average particle size determined from the magnetic analyses for the γ-Fe2O3 …


Teaching College General Chemistry: Techniques Designed To Communicate A Conceptual Framework, Ronald Duchovic Oct 2014

Teaching College General Chemistry: Techniques Designed To Communicate A Conceptual Framework, Ronald Duchovic

Ronald J. Duchovic

General chemistry at the college level is often perceived as a major hurdle by typical undergraduates. Both Freshmen and more advanced students undertake courses in general chemistry either ill-prepared or convinced that the subject matter is beyond their comprehension. With the exception of potential chemistry majors, the vast majority of general chemistry students enter the class simply to satisfy a graduation requirement of their degree program. Consequently, instructors must both communicate an understanding of the subject matter and overcome major barriers to the learning process itself. This paper discusses two techniques which have been utilized for five semesters in general …


Potlib 2001: A Potential Energy Surface Library For Chemical Systems, Ronald Duchovic, Y Volobuev, G Lynch, D Truhlar, T Allison, A Wagner, B Garret, J Corchado Oct 2014

Potlib 2001: A Potential Energy Surface Library For Chemical Systems, Ronald Duchovic, Y Volobuev, G Lynch, D Truhlar, T Allison, A Wagner, B Garret, J Corchado

Ronald J. Duchovic

POTLIB 2001 is a computer program library of global chemical potential energy surface (PES) functions (91 functions in version 1.0) along with test data, a suite of utility programs, and a convenient user interface. The PES programs are written in ANSI standard FORTRAN77 and can be used to determine the Born–Oppenheimer potential energy of chemical systems as a function of the internal coordinates. The accompanying test data allow users to verify local implementations of this library. Finally, the utility programs permit use of this library in conjunction with a variety of chemical dynamics and chemical kinetics computer codes. Interface routines …


Thermal Rate Constants For H + Ch3  Ch4 Recombination. Ii. Comparison Of Experiment And Canonical Variational Transition State Theory, W Hase, S Mondro, Ronald Duchovic, D Hirst Oct 2014

Thermal Rate Constants For H + Ch3  Ch4 Recombination. Ii. Comparison Of Experiment And Canonical Variational Transition State Theory, W Hase, S Mondro, Ronald Duchovic, D Hirst

Ronald J. Duchovic

Canonical variational transition state theory is used to calculate bimolecular rate constants for H + CH, and D + CH, recombination. The calculations are performed on an analytic potential energy surface derived from recent ab initio calculations. Rate constants calculated for this surface are in very good agreement with the experimental values. The H(D)- - -CH3 transitional rocking modes are treated as quantum harmonic oscillators or classical hindered rotors in the calculations. These two treatments give rate constants which agree to within 15%. The variational transition states become tighter as the temperature is increased.


An Application Of Conventional Transition State `Theory To Compute High--Pressure Limit Thermal Rate Coefficients For The Reaction: H(D) + O2  H(D)O2*  Oh(D) + O, Ronald Duchovic, J Pettigrew Oct 2014

An Application Of Conventional Transition State `Theory To Compute High--Pressure Limit Thermal Rate Coefficients For The Reaction: H(D) + O2  H(D)O2*  Oh(D) + O, Ronald Duchovic, J Pettigrew

Ronald J. Duchovic

Several ab initio studies have focused on the minimum energy path region of the hydroperoxyl potential energy surface (PES) (J. Chem. Phys. 1988, 88, 6273) and the saddle point region for H-atom exchange via a T-shaped HO2 complex (J. Chem. Phys. 1989, 91, 2373). Further, the results of additional calculations (J. Chem. Phys. 1991, 94, 7068) have been reported which, when combined with the earlier studies, provide a global description (but not an analytic representation) of the PES for this reaction. In this work, information at the stationary points of the ab initio PES is used within the framework of …


Virtual Inorganic Pedagogical Electronic Resource Learning Objects In Organometallic Chemistry, Barbara Reisner, Joanne Stewart, B Williams, Laurel Goj, Patrick Holland, Hilary Eppley, Adam Johnson Oct 2014

Virtual Inorganic Pedagogical Electronic Resource Learning Objects In Organometallic Chemistry, Barbara Reisner, Joanne Stewart, B Williams, Laurel Goj, Patrick Holland, Hilary Eppley, Adam Johnson

Hilary J. Eppley

Four Virtual Inorganic Pedagogical Electronic Resource (VIPEr) learning objects featuring organometallicChemistry are highlighted.


Building An Online Teaching Community: An Evolving Tale Ofcommunication, Collaboration, Andchemistry, Barbara Reisner, Hilary Eppley, Margret Geselbracht, Elizabeth Jamieson, Adam Johnson, Sheila Smith, Joanne Stewart, Lori Watson, Scott Williams Oct 2014

Building An Online Teaching Community: An Evolving Tale Ofcommunication, Collaboration, Andchemistry, Barbara Reisner, Hilary Eppley, Margret Geselbracht, Elizabeth Jamieson, Adam Johnson, Sheila Smith, Joanne Stewart, Lori Watson, Scott Williams

Hilary J. Eppley

The Interactive Online Network of Inorganic Chemists (IONiC) has grown from a small group of faculty to a national and international network focused on improving inorganicChemistry learning. IONiC’s vision is to create a community of teachers and learners who make teaching visible using social networking tools to share, discuss, test, and assess their teaching methods. The features that have allowed the IONiC community to develop and grow and IONiC’s vision for the future are described. It is likely that the lessons learned apply to other groups seeking to develop professional communities through social networking.


Inorganic Chemistry And Ionic: An Online Community Bringing Cutting-Edge Research Into The Classroom, Elizabeth Jamieson, Hilary Eppley, Margret Geselbracht, Adam Johnson, Barbara Reisner, Sheila Smith, Joanne Stewart, Lori Watson, B Williams Oct 2014

Inorganic Chemistry And Ionic: An Online Community Bringing Cutting-Edge Research Into The Classroom, Elizabeth Jamieson, Hilary Eppley, Margret Geselbracht, Adam Johnson, Barbara Reisner, Sheila Smith, Joanne Stewart, Lori Watson, B Williams

Hilary J. Eppley

This Viewpoint highlights creative ways that members of the Interactive Online Network of Inorganic Chemists (IONiC) are using journal articles from InorganicChemistry to engage undergraduate students in the classroom. We provide information about specificEducational materials and networking features available free of charge to the inorganic community on IONiC's web home, the Virtual Inorganic Pedagogical Electronic Resource (VIPEr, www.ionicviper.org) and describe the benefits of joining this community.


Ionic: A Cyber-Enabled Community Of Practice For Improving Inorganic Chemicaleducation, Hilary Eppley, Adam Johnson, Ethan Benatan, Margret Geselbracht, Joanne Stewart, Barbara Reisner, Lori Watson, B. Williams Oct 2014

Ionic: A Cyber-Enabled Community Of Practice For Improving Inorganic Chemicaleducation, Hilary Eppley, Adam Johnson, Ethan Benatan, Margret Geselbracht, Joanne Stewart, Barbara Reisner, Lori Watson, B. Williams

Hilary J. Eppley

IONiC’s purpose is to enhance the inorganicChemistry classroom and laboratory experience for students and faculty members through the development of a vibrant virtual “community of practice”.


Jce Viper: An Inorganic Teaching And Learning Community, Ethan Benatan, Jezmynne Dene, Hilary Eppley, Margret Gesebracht, Elizabeth Jamieson, Adam Johnson, Barbara Reisner, Joanne Stewart, Lori Watson, B. Williams Oct 2014

Jce Viper: An Inorganic Teaching And Learning Community, Ethan Benatan, Jezmynne Dene, Hilary Eppley, Margret Gesebracht, Elizabeth Jamieson, Adam Johnson, Barbara Reisner, Joanne Stewart, Lori Watson, B. Williams

Hilary J. Eppley

To facilitate the effective sharing of teaching tools among faculty and the development of deep subject knowledge in support of teaching, a group of faculty from predominantly undergraduate institutions has established a virtual community of inorganic chemists, IONiC (Interactive Online Network of Inorganic Chemists). Our mission is to enhance the inorganicChemistry classroom and laboratory experience for students and faculty members through the development of a vibrant, collaborative, and open community. VIPEr, the Virtual Inorganic Pedagogical Electronic Resource, is a Web site that forms the online home for our community. VIPEr is an interactive Web resource that combines a repository of …


Viper: An Online Academic Resource Enhancing Undergraduate Research, Sheila Smith, Sibrina Collins, Hilary Eppley, Margaret Geselbracht, Elizabeth Jamieson, Adam Johnson, Chip Nataro, Barbara Reisner, Joanne Stewart, B. Williams, Lori Watson Oct 2014

Viper: An Online Academic Resource Enhancing Undergraduate Research, Sheila Smith, Sibrina Collins, Hilary Eppley, Margaret Geselbracht, Elizabeth Jamieson, Adam Johnson, Chip Nataro, Barbara Reisner, Joanne Stewart, B. Williams, Lori Watson

Hilary J. Eppley

No abstract provided.


The Role Of Anharmonicity In Hydrogen-Bonded Systems: The Case Of Water Clusters, Berhane Temelso, George Shields Sep 2014

The Role Of Anharmonicity In Hydrogen-Bonded Systems: The Case Of Water Clusters, Berhane Temelso, George Shields

Berhane Temelso

The nature of vibrational anharmonicity has been examined for the case of small water clusters using second-order vibrational perturbation theory (VPT2) applied on second-order Møller–Plesset perturbation theory (MP2) potential energy surfaces. Using a training set of 16 water clusters (H2O)n=2–6,8,9 with a total of 723 vibrational modes, we determined scaling factors that map the harmonic frequencies onto anharmonic ones. The intermolecular modes were found to be substantially more anharmonic than intramolecular bending and stretching modes. Due to the varying levels of anharmonicity of the intermolecular and intramolecular modes, different frequency scaling factors for each region were necessary to achieve the …


An Integrated Systems Approach To Deconstructing Glycosylation, L. Mahal, John Rakus, Kanoelani Pilobello, P. Agrawal Jun 2014

An Integrated Systems Approach To Deconstructing Glycosylation, L. Mahal, John Rakus, Kanoelani Pilobello, P. Agrawal

John F. Rakus

Glycosylation involves the post-translational addition of carbohydrates to protein molecules and is an intricate and indispensable biochemical process. Study of this complicated network of interactions is hindered by the lack of a coding template analogous to the genetic code, and by the vast structural complexity inherent to carbohydrate polymers. We use lectins (non-enzymatic carbohydrate-binding proteins of non-immunological origin) as microarray probes to identify carbohydrate features expressed on cellular surfaces. Specifically, we utilized lectin microarray technology to investigate the differences in carbohydrates expressed by the cell lines of the Nation Cancer Institute’s NCI-60 panel. Our investigation identified tissue-specific expression differences in …


Crystal Structure And Functional Assignment Of Yfau, A Metal Ion Dependent Class Ii Aldolase From Escherichia Coli K12, Dean Rea, Rebecca Hovington, John Rakus, John Gerlt, Vilmos Fu¨Lo¨P, Timothy Bugg, David Roper Jun 2014

Crystal Structure And Functional Assignment Of Yfau, A Metal Ion Dependent Class Ii Aldolase From Escherichia Coli K12, Dean Rea, Rebecca Hovington, John Rakus, John Gerlt, Vilmos Fu¨Lo¨P, Timothy Bugg, David Roper

John F. Rakus

One of the major challenges in the postgenomic era is the functional assignment of proteins using sequence- and structure-based predictive methods coupled with experimental validation. We have used these approaches to investigate the structure and function of theEscherichia coli K-12 protein YfaU, annotated as a putative 4-hydroxy-2-ketoheptane-1,7-dioate aldolase (HpcH) in the sequence databases. HpcH is the final enzyme in the degradation pathway of the aromatic compound homoprotocatechuate. We have determined the crystal structure of apo-YfaU and the Mg2+−pyruvate product complex. Despite greater sequence and structural similarity to HpcH, genomic context suggests YfaU is instead a 2-keto-3-deoxy sugar aldolase like the …


Ba4kfe3o9: A Novel Ferrite Containing Discrete 6-Membered Rings Of Corner-Sharing Feo4 Tetrahedra, Qingbiao Zhao, Saritha Nellutla, Won-Joon Son, Shae Vaughn, Longfei Ye, Mark Smith, Vincent Caignaert, Michael Lufaso, Thomas Pekarek, Alex Smirnov, Myung-Hwan Whangbo, Hans Zur Loye Jun 2014

Ba4kfe3o9: A Novel Ferrite Containing Discrete 6-Membered Rings Of Corner-Sharing Feo4 Tetrahedra, Qingbiao Zhao, Saritha Nellutla, Won-Joon Son, Shae Vaughn, Longfei Ye, Mark Smith, Vincent Caignaert, Michael Lufaso, Thomas Pekarek, Alex Smirnov, Myung-Hwan Whangbo, Hans Zur Loye

Michael W. Lufaso

No abstract provided.


Isoquinoline-Derivatized Tris(2-Pyridylmethyl)Amines As Fluorescent Zinc Sensors With Strict Zn2+/Cd2+ Selectivity, Shawn Burdette, Yuji Mikata, Keiko Kawata, Saaya Takeuchi, Kaori Nakanishi, Hideo Konno, Saori Itami, Keiko Yasuda, Satoshi Tamotsu May 2014

Isoquinoline-Derivatized Tris(2-Pyridylmethyl)Amines As Fluorescent Zinc Sensors With Strict Zn2+/Cd2+ Selectivity, Shawn Burdette, Yuji Mikata, Keiko Kawata, Saaya Takeuchi, Kaori Nakanishi, Hideo Konno, Saori Itami, Keiko Yasuda, Satoshi Tamotsu

Shawn C. Burdette

Tris(2-pyridylmethyl)amine-based fluorescent ligands, N,N-bis(1-isoquinolylmethyl)-2-pyridylmethylamine (1-isoBQPA) and N,N-bis(7-methoxy-1-isoquinolylmethyl)-2-pyridylmethylamine (7-MeO-1-isoBQPA), have been prepared and the Zn2+-induced fluorescence enhancement has been investigated. Upon excitation at 324 nm, 1-isoBQPA exhibits a very weak emission (ϕ = [similar]0.010) in DMF–H2O (1 : 1). Upon Zn2+ addition, the 1-isoBQPA fluorescence increases (ϕZn = 0.055) at 357 nm and 464 nm. The fluorescence enhancement at longer wavelengths is Zn2+-specific, whereas Cd2+ induces a small emission increase at 464 nm (ICd/I0 = 1.1, ICd/IZn = 14%). The Zn2+/Cd2+ selectivity of the fluorescent response correlates with the Cd–Nisoquinoline and Zn–Nisoquinoline bond distances measured in the crystal structures. Introduction of …


Quantum Chemical Studies Of Carbonyl Oxide Chemistry In Combustion And In The Lower Atmosphere Peroxides, Keith Kuwata Apr 2014

Quantum Chemical Studies Of Carbonyl Oxide Chemistry In Combustion And In The Lower Atmosphere Peroxides, Keith Kuwata

Keith Kuwata

No abstract provided.


Computational Treatments Of Peroxy Radicals In Combustion And Atmospheric Reactions, Keith Kuwata Apr 2014

Computational Treatments Of Peroxy Radicals In Combustion And Atmospheric Reactions, Keith Kuwata

Keith Kuwata

No abstract provided.