Physical Sciences and Mathematics | Open Access Articles

Halothiobacillus Neapolitanus Carboxysomes Sequester Heterologous And Chimeric Rubisco Species, Balaraj B. Menon, Zhicheng Dou, Sabine Heinhorst, Jessup M. Shively, Gordon C. Cannon

Faculty Publications

Background: The carboxysome is a bacterial microcompartment that consists of a polyhedral protein shell filled with ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO), the enzyme that catalyzes the first step of CO(2) fixation via the Calvin-Benson-Bassham cycle. Methodology/Principal Findings: To analyze the role of RubisCO in carboxysome biogenesis in vivo we have created a series of Halothiobacillus neapolitanus RubisCO mutants. We identified the large subunit of the enzyme as an important determinant for its sequestration into alpha-carboxysomes and found that the carboxysomes of H. neapolitanus readily incorporate chimeric and heterologous RubisCO species. Intriguingly, a mutant lacking carboxysomal RubisCO assembles empty carboxysome shells of …

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Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, Jianhua Rong, L. Andrew Lee, Kai Li, Brandon Harp, Charlene M. Mello, Zhongwei Niu, Qian Wang

Faculty Publications

Fibrillar M13 bacteriophages were used as basic building blocks to generate thin films with aligned nanogrooves, which, upon chemical grafting with RGD peptides, guide cell alignment and orient the cell outgrowth along defined directions.

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Structure Of The Thioredoxin-Like Domain Of Yeast Glutaredoxin 3, Lydia M. Gibson, Nin N. Dingra, Caryn E. Outten, Lukasz Lebioda

Faculty Publications

Yeast glutaredoxin 3 (Grx3) is a cytosolic protein that regulates the activity of the iron-responsive transcriptional activator Aft1. This member of the monothiol glutaredoxin family contains a thioredoxin-like domain and a glutaredoxin-like domain, which both possess a monothiol active site. The crystal structure of the thioredoxin-like domain has been determined at 1.5 Å resolution and represents the first published structure of this domain for the monothiol glutaredoxin family. The loop containing the signature motif WAxxC is partially disordered, indicating a greater degree of flexibility in this region compared with classical dithiol thioredoxins with a WCGPC active-site motif.

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Stable Long-Time Semiclassical Description Of Zero-Point Energy In High-Dimensional Molecular Systems, Sophya Garashchuk, Vitaly A. Rassolov

Faculty Publications

Semiclassical implementation of the quantum trajectory formalism [J. Chem. Phys. 120, 1181 (2004)] is further developed to give a stable long-time description of zero-point energy in anharmonic systems of high dimensionality. The method is based on a numerically cheap linearized quantum force approach; stabilizing terms compensating for the linearization errors are added into the time-evolution equations for the classical and nonclassical components of the momentum operator. The wave function normalization and energy are rigorously conserved. Numerical tests are performed for model systems of up to 40 degrees of freedom.

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The Role Of Upstream Sequences In Selecting The Reading Frame On Tmrna, Allen R. Buskirk, Mickey R. Miller, David W. Healey, Jonathan D. Dewey, Stephen G. Robison

Faculty Publications

tmRNA acts first as a tRNA and then as an mRNA to rescue stalled ribosomes in eubacteria. Two unanswered questions about tmRNA function remain: how does tmRNA, lacking an anticodon, bypass the decoding machinery and enter the ribosome? Secondly, how does the ribosome choose the proper codon to resume translation on tmRNA? According to the -1 triplet hypothesis, the answer to both questions lies in the unique properties of the three nucleotides upstream of the first tmRNA codon. These nucleotides assume an A-form conformation that mimics the codon-anticodon interaction, leading to recognition by the decoding center and choice of the …

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Manipulating The Cavity Of A Porous Material Changes The Photoreactivity Of Included Guests, Mahender B. Dewal, Yuewen Xu, Jun Yang, Fiaz Mohammed, Mark D. Smith, Linda S. Shimizu

Faculty Publications

Changing an ether to a ketone within the framework of a bis-urea macrocycle has little effect on the supramolecular assembly of this building block into porous crystals but introduces a triplet sensitizer into the framework that dramatically alters the photochemical reactions of included guests.

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Co2 Fixation Kinetics Of Halothiobacillus Neapolitanus Mutant Carboxysomes Lacking Carbonic Anhydrase Suggest The Shell Acts As A Diffusional Barrier For Co2, Zhicheng Dou, Sabine Heinhorst, Eric B. Williams, C. Daniel Murin, Jessup M. Shively, Gordon C. Cannon

Faculty Publications

The widely accepted models for the role of carboxysomes in the carbon-concentrating mechanism of autotrophic bacteria predict the carboxysomal carbonic anhydrase to be a crucial component. The enzyme is thought to dehydrate abundant cytosolic bicarbonate and provide ribulose 1.5-bisphosphate carboxylase/oxygenase (RubisCO) sequestered within the carboxysome with sufficiently high concentrations of its substrate, CO₂, to permit its efficient fixation onto ribulose 1,5-bisphosphate. In this study, structure and function of carboxysomes purified from wild type Halothiobacillus neapolitanus and from a high CO₂-requiring mutant that is devoid of carboxysomal carbonic anhydrase were compared. The kinetic constants for the carbon …

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Comment On “Contact Conditions For The Charge In The Theory Of The Electrical Double Layer”, Douglas Henderson, L. B. Bhuiyan

Faculty Publications

Exact results in any field, including statistical mechanics, are both aesthetically pleasing and very valuable in assessing theoretical approximations.

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Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy

Faculty Publications

Relaxation of highly vibrationally excited pyrimidine (C4N2H4) by collisions with carbon dioxide has been investigated using diode laser transient absorption spectroscopy. Vibrationally hot pyrimidine (E'=40,635 cm^-1) was prepared by 248-nm excimer laser excitation, followed by rapid radiationless relaxation to the ground electronic state. The nascent rotational population distribution (J=58–80) of the 0000 ground state of CO2 resulting from collisions with hot pyrimidine was probed at short times following the excimer laser pulse. Doppler spectroscopy was used to measure the CO2 recoil velocity distribution for J=58–80 of the 0000 state. Rate constants and probabilities for collisions populating these CO2 rotational states …

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Ozone Exposure In A Mouse Model Induces Airway Hyperreactivity That Requires The Presence Of Natural Killer T Cells And Il-17, Paul B. Savage, Muriel Pichavant, Sho Goya, Everett H. Meyer, Richard A. Johnston, Hye Y. Kim, Ponpan Matangkasombut, Ming Zhu, Yoichiro Iwakura, Rosemarie H. Dekruyff, Stephanie A. Shore, Dale T. Umetsu

Faculty Publications

Exposure to ozone, which is a major component of air pollution, induces a form of asthma that occurs in the absence of adaptive immunity. Although ozone-induced asthma is characterized by airway neutrophilia, and not eosinophilia, it is nevertheless associated with airway hyperreactivity (AHR), which is a cardinal feature of asthma. Because AHR induced by allergens requires the presence of natural killer T (NKT) cells, we asked whether ozone-induced AHR had similar requirements. We found that repeated exposure of wild-type (WT) mice to ozone induced severe AHR associated with an increase in airway NKT cells, neutrophils, and macrophages. Surprisingly, NKT cell-deficient …

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Singlet Oxygen Chemistry In Water: A Porous Vycor Glasssupported Photosensitizer, David Aebisher, Nikolay S. Azar, Matibur Zamadar, Naveen Gandra, Harry D. Gafney, Roumei Gao, Alexander Greer

Faculty Publications

Singlet molecular oxygen [1O2 (1Δg)] is generated cleanly in aqueous solution upon irradiation of a heterogeneous complex, meso-tetra(N-methyl-4-pyridyl)porphine (1) adsorbed onto porous Vycor glass (PVG). The cationic photosensitizer 1 tightly binds onto PVG and gives a stable material, which does not dissociate 1 into the surrounding aqueous phase. The production of 1O2 was measured by monitoring the time-resolved 1O2 (1Δg) phosphorescence at 1270 nm. Indirect analysis of 1O2 generation was also carried out with the photooxidation oftrans-2-methyl-2-pentenoate anion, which afforded the corresponding hydroperoxide. Sensitizer-1-impregnated PVG gives rise to a new singlet …

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Singlet Oxygen Chemistry In Water. 2. Photoexcited Sensitizer Quenching By O2 At The Water−Porous Glass Interface, Jovan Giaimuccio, Matibur Zamadar, David Aebisher, Gerald J. Meyer, Alexander Greer

Faculty Publications

Insight into the O2 quenching mechanism of a photosensitizer (static or dynamic) would be useful for the design of heterogeneous systems to control the mode of generation of 1O2 in water. Here, we describe the use of a photosensitizer, meso-tetra(N-methyl-4-pyridyl)porphine (1), which was adsorbed onto porous Vycor glass (PVG). A maximum loading of 1.1 × 10−6 mol 1 per g PVG was achieved. Less than 1% of the PVG surface was covered with photosensitizer 1, and the penetration of 1 reaches a depth of 0.32 mm along all faces of the glass. Time-resolved measurements …

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Tetra-Î¼-Aqua-Octaaquabis(Î¼-4-Chloropyridine-2,6-Dicarboxylato(Bis(4-Chloro-Pyridine-2,6-Dicarboxylato)Tricobalt(Ii)-Disodium(I) Bis[Triaquabis(4-Chloro-Pyridine-2,6-Dicarboxylato)Cobalt(Ii)] Hexahydrate, Lamaryet Moody, Shawna Balof, Shanika Smith, Varma H. Rambaran, Don Vanderveer, Alvin A. Holder

Faculty Publications

The title compound, [Co₃Na₂(C₇₂ClNO₄)₄(H₂O)₁₂][Co(C₇H₂ClNO₄(H₂O)₃]₂·6H₂O, consists of a centrosymmetric dimer of [Co^II(dipicCl)₂]^2- complex dianions [dipicCl is 4-chloropyridine-2,6-dicarboxylate] bridged by an [Na₂Co^II(H₂O)₁₂]⁴⁺ tetracationic cluster, two independent [Co(dipicCl)(H₂O)₃] complexes, and six water molecules of crystallization. The metals are all six-coordinate with distorted octahedral geometries. The [Co^II(dipicCl)(H₂O)₃] complexes are neutral, with …

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Full-Text Articles in Physical Sciences and Mathematics

Halothiobacillus Neapolitanus Carboxysomes Sequester Heterologous And Chimeric Rubisco Species, Balaraj B. Menon, Zhicheng Dou, Sabine Heinhorst, Jessup M. Shively, Gordon C. Cannon

Faculty Publications

Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, Jianhua Rong, L. Andrew Lee, Kai Li, Brandon Harp, Charlene M. Mello, Zhongwei Niu, Qian Wang

Faculty Publications

Structure Of The Thioredoxin-Like Domain Of Yeast Glutaredoxin 3, Lydia M. Gibson, Nin N. Dingra, Caryn E. Outten, Lukasz Lebioda

Faculty Publications

Stable Long-Time Semiclassical Description Of Zero-Point Energy In High-Dimensional Molecular Systems, Sophya Garashchuk, Vitaly A. Rassolov

Faculty Publications

The Role Of Upstream Sequences In Selecting The Reading Frame On Tmrna, Allen R. Buskirk, Mickey R. Miller, David W. Healey, Jonathan D. Dewey, Stephen G. Robison

Faculty Publications

Manipulating The Cavity Of A Porous Material Changes The Photoreactivity Of Included Guests, Mahender B. Dewal, Yuewen Xu, Jun Yang, Fiaz Mohammed, Mark D. Smith, Linda S. Shimizu

Faculty Publications

Co2 Fixation Kinetics Of Halothiobacillus Neapolitanus Mutant Carboxysomes Lacking Carbonic Anhydrase Suggest The Shell Acts As A Diffusional Barrier For Co2, Zhicheng Dou, Sabine Heinhorst, Eric B. Williams, C. Daniel Murin, Jessup M. Shively, Gordon C. Cannon

Faculty Publications

Comment On “Contact Conditions For The Charge In The Theory Of The Electrical Double Layer”, Douglas Henderson, L. B. Bhuiyan

Faculty Publications

Quenching Of Highly Vibrationally Excited Pyrimidine By Collisions With Co4, Jeremy A. Johnson, Andrew M. Duffin, Brian J. Hom, Karl E. Jackson, Eric T. Sevy

Faculty Publications

Faculty Publications

Singlet Oxygen Chemistry In Water: A Porous Vycor Glasssupported Photosensitizer, David Aebisher, Nikolay S. Azar, Matibur Zamadar, Naveen Gandra, Harry D. Gafney, Roumei Gao, Alexander Greer

Faculty Publications

Singlet Oxygen Chemistry In Water. 2. Photoexcited Sensitizer Quenching By O2 At The Water−Porous Glass Interface, Jovan Giaimuccio, Matibur Zamadar, David Aebisher, Gerald J. Meyer, Alexander Greer

Faculty Publications

Faculty Publications