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2010

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Articles 31 - 60 of 71

Full-Text Articles in Biotechnology

Evolution Of New Enzymatic Function By Structural Modulation Of Cysteine Reactivity In Pseudomonas Fluorescens Isocyanide Hydratase, Mahadevan Lakshminarasimhan, Peter Madzelan, Ruth Nan, Nicole Marie Milkovic, Mark A. Wilson Jan 2010

Evolution Of New Enzymatic Function By Structural Modulation Of Cysteine Reactivity In Pseudomonas Fluorescens Isocyanide Hydratase, Mahadevan Lakshminarasimhan, Peter Madzelan, Ruth Nan, Nicole Marie Milkovic, Mark A. Wilson

Department of Biochemistry: Faculty Publications

Isocyanide (formerly isonitrile) hydratase (EC 4.2.1.103) is an enzyme of the DJ-1 superfamily that hydrates isocyanides to yield the corresponding N-formamide. In order to understand the structural basis for isocyanide hydratase (ICH) catalysis, we determined the crystal structures of wild-type and several site-directed mutants of Pseudomonas fluorescens ICH at resolutions ranging from 1.0 to 1.9 Å. We also developed a simple UV-visible spectrophotometric assay for ICH activity using 2-naphthyl isocyanide as a substrate. ICH contains a highly conserved cysteine residue (Cys101) that is required for catalysis and interacts with Asp17, Thr102, and an ordered water molecule in the active …


Apoptosis Initiation And Angiogenesis Inhibition: Melanoma Targets For Nanosecond Pulsed Electric Fields, Xinhua Chen, Juergen F. Kolb, R. James Swanson, Karl H. Schoenbach, Stephen J. Beebe Jan 2010

Apoptosis Initiation And Angiogenesis Inhibition: Melanoma Targets For Nanosecond Pulsed Electric Fields, Xinhua Chen, Juergen F. Kolb, R. James Swanson, Karl H. Schoenbach, Stephen J. Beebe

Bioelectrics Publications

Many effective anti-cancer strategies target apoptosis and angiogenesis mechanisms. Applications of non-ionizing, nanosecond pulsed electric fields (nsPEFs) induce apoptosis in vitro and eliminate cancer in vivo; however in vivo mechanisms require closer analysis. These studies investigate nsPEF-induced apoptosis and anti-angiogenesis examined by fluorescent microscopy, immunoblots, and morphology. Six hours after treatment with one hundred 300 ns pulses at 40 kV/cm, cells transiently expressed active caspases indicating that caspase-mediated mechanisms. Three hours after treatment transient peaks in Histone 2AX phosphorylation coincided with terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and pyknotic nuclei, suggesting caspase-independent mechanisms on nuclei/DNA. Large …


Nih Guidelines On Human Embryonic Stem Cell Research In Context: Clarity Or Confusion?, Karen H. Rothenberg, Michael R. Ulrich Jan 2010

Nih Guidelines On Human Embryonic Stem Cell Research In Context: Clarity Or Confusion?, Karen H. Rothenberg, Michael R. Ulrich

Faculty Scholarship

No abstract provided.


Effects Of Diesel And Biodiesel Blends On Engine Performance And Efficiency, Christopher Hunt, Donald Johnson, Don Edgar Jan 2010

Effects Of Diesel And Biodiesel Blends On Engine Performance And Efficiency, Christopher Hunt, Donald Johnson, Don Edgar

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Tests were conducted during the summer of 2009 on a John Deere 3203 diesel tractor to determine differences in specific fuel consumption (sfc), power take-off (PTO) torque (Nm), and PTO power (kW), between ultralow sulfur No. 2 Diesel (D2), 20% biodiesel (B20), 50% biodiesel (B50), and100% biodiesel (B100). Four 1-hr tests were conducted with D2, while three 1-hr tests were conducted with B20, B50, and B100. The results indicated that there was no significant (p < 0.05) difference between D2 and B20 for power or torque. Fueling with B50 resulted in significantly lower power and torque than fueling with D2 or B20, but significantly higher power and torque than fueling with B100. There were significant differences between each fuel in sfc; as the biodiesel blend increased, sfc also increased. Based on these data, B20 appears to be the optimal biodiesel blend for this and similar compact utility tractors since fueling with B20 resulted in no significant loss in power or torque (compared to D2) and only a slight increase in fuel consumption.


Evaluating The Target Pipeline In A Pharmaceutical Acquisition, Daniel Vass Jan 2010

Evaluating The Target Pipeline In A Pharmaceutical Acquisition, Daniel Vass

Business and Economics Honors Papers

Many firms in the pharmaceutical industry turn to acquisitions when faced with gaps in their drug development pipelines and patent expirations as an alternative to making long-term investments in internal research and development. Investors are generally negative on this strategy, and upon the announcement of a pharmaceutical acquisition the stock of the acquiring firm often drops. This decline in share price creates an opportunity for the investor who can identify the characteristics of a target firm that increase the probability that the transaction will ultimately be a success, as measured by the subsequent appreciation in the acquirer's stock. It is …


Quantitative Pcr Assay For Mycobacterium Pseudoshottsii And Mycobacterium Shottsii And Application To Environmental Samples And Fishes From The Chesapeake Bay, D. T. Gauthier, K. S. Reece, J. Xiao, M. W. Rhodes, H. I. Kator, R. J. Latour, C. F. Bonzek, J. M. Hoenig, W. K. Vogelbein Jan 2010

Quantitative Pcr Assay For Mycobacterium Pseudoshottsii And Mycobacterium Shottsii And Application To Environmental Samples And Fishes From The Chesapeake Bay, D. T. Gauthier, K. S. Reece, J. Xiao, M. W. Rhodes, H. I. Kator, R. J. Latour, C. F. Bonzek, J. M. Hoenig, W. K. Vogelbein

Biological Sciences Faculty Publications

Striped bass (Morone saxatilis) in the Chesapeake Bay are currently experiencing a very high prevalence of mycobacteriosis associated with newly described Mycobacterium species, Mycobacterium pseudoshottsii and M. shottsii. The ecology of these mycobacteria outside the striped bass host is currently unknown. In this work, we developed quantitative real-time PCR assays for M. pseudoshottsii and M. shottsii and applied these assays to DNA extracts from Chesapeake Bay water and sediment samples, as well as to tissues from two dominant prey of striped bass, Atlantic menhaden (Brevoortia tyrannus) and bay anchovy (Anchoa mitchilli). Mycobacterium …


Purification And Analysis Of Bacterial-And Plant-Derived Scfv Antibodies For The Detection Of Cucumber Mosaic Virus, Wong C.F.Y. Jan 2010

Purification And Analysis Of Bacterial-And Plant-Derived Scfv Antibodies For The Detection Of Cucumber Mosaic Virus, Wong C.F.Y.

Student Works (2010-2019)

abstract N/A


Biolistic Transformation Of Oil Palm Using The Phosphomannose Isomerase (Pmi) Gene As The Positive Selectable Marker., Bahariah Bohari Jan 2010

Biolistic Transformation Of Oil Palm Using The Phosphomannose Isomerase (Pmi) Gene As The Positive Selectable Marker., Bahariah Bohari

Student Works (2010-2019)

The selectable marker system based on the Escherichia coli phosphomannose isomerase (pmi) gene was adapted for genetic transformation of oil palm. This system makes use of the pmi gene that encodes phosphomannose isomerase, which converts mannose-6-phosphate to fructose-6-phosphate and uses mannose as the selection agent. This is to anticipate the future requirement of using non-antibiotic resistance genes for the commercialization of transgenic oil palm. The use of antibiotic or herbicide-based selection systems has caused much public concern due to inadequate knowledge of the agents’ impact on the environment and on human health. In this study, four transformation vectors, namely pMI3, …


Studies On The Bioactive Properties Of Selected Plant And Fermented Extracts., Saravana Kumar Sinniah Jan 2010

Studies On The Bioactive Properties Of Selected Plant And Fermented Extracts., Saravana Kumar Sinniah

Student Works (2010-2019)

The aim of this study was to isolate protein/peptide and secondary metabolites from plant and fermented sources. The extracts were used to test for antimicrobial and antioxidant properties. In the current study protein/peptide extracts of Allium sativum showed promising results with a 15mm inhibition zone against Escherichia coli, 28mm against Staphylococcus aureus, 16.3mm against Bacillus cereus and 9mm against Pseudomonas aeruginosa. The minimum bacteriocidal concentration (MBC) results showed that Allium sativum protein/peptide extract is only bacteriostatic and not bacteriocidal. Andrographis paniculata showed the most promising result for the ethanolic extracts with an inhibition zone of 14mm against B. cereus, 11.5mm …


Estimation Of The Product Yield And Collection Efficiency Of Peripheral Blood Stem Cell Harvesting Using Peripheral Blood Cd34[+] Cells Quantification., Habsah Aziz Jan 2010

Estimation Of The Product Yield And Collection Efficiency Of Peripheral Blood Stem Cell Harvesting Using Peripheral Blood Cd34[+] Cells Quantification., Habsah Aziz

Student Works (2010-2019)

Peripheral blood stem cells (PBSC) have been used for transplantation since the early 1990s. CD34+ has been used as a marker of hematopoietic stem cells to determine the optimal timing for PBSC harvesting. However, a wide ranges of CD34+ cells cut-off values from 8/ul to 66/ul have been used to initiate PBSC harvesting in autologous patients. We performed here a study to determine the peripheral blood CD34+ cells cut-off value for the prediction of stem cell yield of 2 x106 CD34+ cells/kg body weight patients, to study the correlation between peripheral blood CD34+ cells and stem cell yield, to study …


Diversity And Antioxidant Activity Of Trametes Fr. In Malaysia., Noraswati Mohd Nor Rashid Jan 2010

Diversity And Antioxidant Activity Of Trametes Fr. In Malaysia., Noraswati Mohd Nor Rashid

Student Works (2010-2019)

Research on antioxidant properties as a natural antioxidant, particularly in polypores, have been widely done since the past decade. It is known that antioxidant capacity is essential in protecting organisms and cells from damage brought on by oxidative which is believed to be the cause for ageing and degenerative diseases. In this study, biodiversity and antioxidant activity of Malaysian Trametes spp. which is from the group of polypores were investigated. Polypores were collected in Peninsular Malaysia forests from the year 2006 until 2007. The species were identified by taxonomic keys based on macromorphology and micromorphology analysis. Trametes hirsuta, T. pocas, …


Cytotoxic And Anti-Human Papillomavirus Activites In Selected Vegetables., Maizatul Azmah Ab. Latiff Jan 2010

Cytotoxic And Anti-Human Papillomavirus Activites In Selected Vegetables., Maizatul Azmah Ab. Latiff

Student Works (2010-2019)

An appropriate way to control cancer is chemoprevention as a large number of compounds have been observed to prevent the occurrence of cancer and variety of mechanisms exists for producing such protective effects. Numerous epidemiological studies have shown that diets rich in vegetables are associated with a decreased risk of cancer. Chemoprevention involves the use of natural or laboratory made substances to prevent cancer or reduce risk cancer.The E6 oncoprotein from oncogenic Human papillomaviruses (HPVs) has exhibit functions in tumorigenesis, regulation of transcriptions and apoptosis. E6 product from oncogenic viral type like HPV 16 can bind the tumor suppressor p53 …


Synthesis, Characterization And Biological Activities Of Three Indole Schiff Bases And Their Copper And Nickel Complexes., Nazzatush Shimar Jamaludin Jan 2010

Synthesis, Characterization And Biological Activities Of Three Indole Schiff Bases And Their Copper And Nickel Complexes., Nazzatush Shimar Jamaludin

Student Works (2010-2019)

Three derivatives of indole-3-carboxaldehyde with indole-3-acetic hydrazide and their copper(II) and nickel(II) complexes were synthesized. The Schiff base compounds were varied on the substituent where each compound holds a hydrogen, chlorine and bromine atom on the 5th position of indole-3-carboxaldehyde. The structures of the ligands and their complexes were elucidated by various characterization methods. All compounds were screened for their biological effects on neuroprotective screening (in vitro), acute toxicity test (in vivo), ethanol-induced gastric ulcer (anti-ulcer) and glucose tolerance test (antidiabetic). All compounds except bromine-containing compounds were not dose dependent while compounds with bromine displayed significant results, acting as inhibitory …


Agrobacterium-Mediated Transformation Of Cryptocoryne Willisii With Gus And Mgfp 5 Reporter Genes / Wong Sher Ming, Wong Sher Ming Jan 2010

Agrobacterium-Mediated Transformation Of Cryptocoryne Willisii With Gus And Mgfp 5 Reporter Genes / Wong Sher Ming, Wong Sher Ming

Student Works (2010-2019)

In this study, a simple method using Murashige and Skoog basal medium (1962) supplemented with 6-BA alone was developed for direct multiple shoots induction from shoot base culture of C. willisii. Shoots proliferation and elongation were achieved on a single medium without the need of subculturing. The optimum concentration of 6-BA for direct shoots regeneration of C. willisii was investigated. It was found to be 6 mg/ L. Optimum media was then used for regenerate and propagate of transformed C. willisii. On the other hand, ransformation of C. willisii with Agrobacterium tumefaciens strain LBA4404 harbouring pCAMBIA1304 was performed. Effects on …


Application Of Pcr-Based Serogrouping Of Salmonella Enterica., Mohammed Elbagir Mohammed Elhassan Nori Jan 2010

Application Of Pcr-Based Serogrouping Of Salmonella Enterica., Mohammed Elbagir Mohammed Elhassan Nori

Student Works (2010-2019)

Serotyping is the most fundamental approach in epidemiological surveillance and outbreak investigations for Salmonella. Many multiplex PCR assays have been reported for serotyping Salmonella based on O and H antigens. The aim of this study was to apply and improve the approach in differentiation and serotyping Salmonella enterica strains by combination of sequential multiplex PCRs targeting the O, H and Vi antigens of Salmonella, and this achieved by working on 126 strains. All the strains were purified on BSA and produced black colonies of Salmonella. The strains were confirmed by PCR amplification gene that targets the hilA. 122 of 126 …


In Vitro Cultures For Production Of Zerumbone And Mass Propagation In Zingiber Zerumbet Smith., Farah Diana Idris Jan 2010

In Vitro Cultures For Production Of Zerumbone And Mass Propagation In Zingiber Zerumbet Smith., Farah Diana Idris

Student Works (2010-2019)

Lempoyang (Zingiber zerumbet Smith.) is an important plant which has been propagated because of its medicinal values. Lempoyang is widely used as a folk medicine in Asian countries such as Malaysia, Indonesia, India and Taiwan. Zerumbone, a cyclic sesqueterpene found to be the major and main bioactive compound that gives great potential in medicinal purposes especially in the treatment of chronic diseases based on recent reports. Recently, it was found that zerumbone inhibited the growth of human leukemia cell line, HL-60 cell. Even though there are so many great values contain in the lempoyang but it is hard to obtain …


Identification And Characterization Of Oxalate Oxidoreductase, A Novel Thiamine Pyrophosphate-Dependent 2-Oxoacid Oxidoreductase That Enables Anaerobic Growth On Oxalate, Elizabeth Pierce, Donald F. Becker, Stephen W. Ragsdale Jan 2010

Identification And Characterization Of Oxalate Oxidoreductase, A Novel Thiamine Pyrophosphate-Dependent 2-Oxoacid Oxidoreductase That Enables Anaerobic Growth On Oxalate, Elizabeth Pierce, Donald F. Becker, Stephen W. Ragsdale

Department of Biochemistry: Faculty Publications

Moorella thermoacetica is an anaerobic acetogen, a class of bacteria that is found in the soil, the animal gastrointestinal tract, and the rumen. This organism engages the Wood-Ljungdahl pathway of anaerobic CO2 fixation for heterotrophic or autotrophic growth. This paper describes a novel enzyme, oxalate oxidoreductase (OOR), that enables M. thermoacetica to grow on oxalate, which is produced in soil and is a common component of kidney stones. Exposure to oxalate leads to the induction of three proteins that are subunits of OOR, which oxidizes oxalate coupled to the production of two electrons and CO2 or bicarbonate. Like …


Functional Hybrid Rubisco Enzymes With Plant Small Subunits And Algal Large Subunits Engineered Rbcs Cdna For Expression In Chlamydomonas, Todor Genkov, Moritz Meyer, Howard Griffiths, Robert J. Spreitzer Jan 2010

Functional Hybrid Rubisco Enzymes With Plant Small Subunits And Algal Large Subunits Engineered Rbcs Cdna For Expression In Chlamydomonas, Todor Genkov, Moritz Meyer, Howard Griffiths, Robert J. Spreitzer

Department of Biochemistry: Faculty Publications

There has been much interest in the chloroplast-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) as a target for engineering an increase in net CO2 fixation in photosynthesis. Improvements in the enzyme would lead to an increase in the production of food, fiber, and renewable energy. Although the large subunit contains the active site, a family of rbcS nuclear genes encodes the Rubisco small subunits, which can also influence the carboxylation catalytic efficiency and CO2/O2 specificity of the enzyme. To further define the role of the small subunit in Rubisco function, small subunits from spinach, Arabidopsis, …


Increased Perfusion And Angiogenesis In A Hindlimb Ischemia Model With Plasmid Fgf-2 Delivered By Noninvasive Electroporation, B. Ferraro, Y. L. Cruz, M. Baldwin, D. Coppola, R. Heller Jan 2010

Increased Perfusion And Angiogenesis In A Hindlimb Ischemia Model With Plasmid Fgf-2 Delivered By Noninvasive Electroporation, B. Ferraro, Y. L. Cruz, M. Baldwin, D. Coppola, R. Heller

Bioelectrics Publications

Gene therapy approaches delivering fibroblast growth factor-2 (FGF-2) have shown promise as a potential treatment for increasing blood flow to ischemic limbs. Currently, effective noninvasive techniques to deliver plasmids encoding genes of therapeutic interest, such as FGF-2, are limited. We sought to determine if intradermal injection of plasmid DNA encoding FGF-2 (pFGF) followed by noninvasive cutaneous electroporation (pFGFE+) could increase blood flow and angiogenesis in a rat model of hindlimb ischemia. pFGFE+ or control treatments were administered on postoperative day 0. Compared to injection of pFGF alone (pFGFE-), delivery of pFGFE+ significantly increased FGF-2 expression for 10 days. Further, the …


Electric Pulses To Prepare Feeder Cells For Sustaining And Culturing Of Undifferentiated Embryonic Stem Cells, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu Jan 2010

Electric Pulses To Prepare Feeder Cells For Sustaining And Culturing Of Undifferentiated Embryonic Stem Cells, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Current challenges in embryonic-stem-cell (ESC) research include inability of sustaining and culturing of undifferentiated ESCs over time. Growth-arrested feeder cells are essential to the culture and sustaining of undifferentiated ESCs, and they are currently prepared using gammaradiation and chemical inactivation. Both techniques have severe limitations. In this study, we developed a new, simple and effective technique (pulsed-electric-fields, PEFs) to produce viable growth-arrested cells (RTS34st) and used them as high-quality feeder cells to culture and sustain undifferentiated zebrafish ESCs over time. The cells were exposed to 25 sequential 10- nanosecond-electric-pulses (10nsEPs) of 25, 40 and 150 kV/cm with 1s pulse interval, …


Antibactertial Property And Toxcity Study Of Medicinal Plant Tinospora Crispa L., Altammar Khadijah Ahmed Y. Jan 2010

Antibactertial Property And Toxcity Study Of Medicinal Plant Tinospora Crispa L., Altammar Khadijah Ahmed Y.

Student Works (2010-2019)

Tinospora crispa is a medically important herb used for centuries in traditional medicine for the treatment of various ailments. The aim of this study was to investigate the safety of the aqueous and alcoholic extract of Tinospora crispa by determining its toxicological effects after acute administration in rats, and to investigate the antibacterial activity of both extracts. Disc diffusion and broth dilution methods were carried out in determining the antibacterial effects of the plant extract on the pure cultures of clinical isolates of 8 MRSA and S. aureus ATCC strain. The disc-diffusion method of the ethanolic extracts showed inhibition zone …


Antagonistic Activity Of Selected Marine-Derived Streptomyces Spp. Against Plesiomonas Shigelloides., Angelyn Melaya Kloni Jan 2010

Antagonistic Activity Of Selected Marine-Derived Streptomyces Spp. Against Plesiomonas Shigelloides., Angelyn Melaya Kloni

Student Works (2010-2019)

In this study, primary and secondary screenings were conducted to evaluate the antibacterial and anti-yeast potential of the eleven selected marine-derived Streptomyces spp., particularly against P. shigelloides. The strains were categorized into three colour groups for morphological grouping according to the colour of aerial mycelium; namely grey, yellow green, and white colour groups. Diffusible pigments were produced by eight of the strains tested. Strain(s) from grey and white with red diffusible pigments colour groups displayed strong antibacterial activity. The yeasts tested were resistant to the bioactive metabolite(s) produced by some of the Streptomyces spp. which had shown high activity against …


Diversity Of Protein And Mrna Forms Of Mammalian Methionine Sulfoxide Reductase B1 Due To Intronization And Protein Processing, Xinwen Liang, Dmitri E. Fomenko, Deame Hua, Alaattin Kaya, Vadim N. Gladyshev Jan 2010

Diversity Of Protein And Mrna Forms Of Mammalian Methionine Sulfoxide Reductase B1 Due To Intronization And Protein Processing, Xinwen Liang, Dmitri E. Fomenko, Deame Hua, Alaattin Kaya, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Background: Methionine sulfoxide reductases (Msrs) are repair enzymes that protect proteins from oxidative stress by catalyzing stereospecific reduction of oxidized methionine residues. MsrB1 is a selenocysteine-containing cytosolic/nuclear Msr with high expression in liver and kidney.

Principal Findings: Here, we identified differences in MsrB1 gene structure among mammals. Human MsrB1 gene consists of four, whereas the corresponding mouse gene of five exons, due to occurrence of an additional intron that flanks the stop signal and covers a large part of the 39-UTR. This intron evolved in a subset of rodents through intronization of exonic sequences, whereas the human gene structure represents …


Incorporating Genomics And Bioinformatics Across The Life Sciences Curriculum, Jayna L. Ditty, Christopher A. Kvaal, Brad Goodner, Sharyn K. Freyermuth, Cheryl Bailey, Robert A. Britton, Stuart G. Gordon, Sabine Heinhorst, Kelynne Reed, Zhaohui Xu, Erin R. Sanders-Lorenz, Seth Axen, Edwin Kim, Mitrick Johns, Kathleen Scott, Cheryl A. Kerfeld Jan 2010

Incorporating Genomics And Bioinformatics Across The Life Sciences Curriculum, Jayna L. Ditty, Christopher A. Kvaal, Brad Goodner, Sharyn K. Freyermuth, Cheryl Bailey, Robert A. Britton, Stuart G. Gordon, Sabine Heinhorst, Kelynne Reed, Zhaohui Xu, Erin R. Sanders-Lorenz, Seth Axen, Edwin Kim, Mitrick Johns, Kathleen Scott, Cheryl A. Kerfeld

Department of Biochemistry: Faculty Publications

Undergraduate life sciences education needs an overhaul, as clearly described in the National Research Council of the National Academies’ publication BIO 2010: Transforming Undergraduate Education for Future Research Biologists. Among BIO 2010’s top recommendations is the need to involve students in working with real data and tools that reflect the nature of life sciences research in the 21st century [1]. Education research studies support the importance of utilizing primary literature, designing and implementing experiments, and analyzing results in the context of a bona fide scientific question [1–12] in cultivating the analytical skills necessary to become a scientist. Incorporating these …


Regulation Of Sealing Ring Formation By L-Plastin And Cortactin In Osteoclasts, Tao Ma, Kavitha Sadashivalah, Nandakumar Madayiputhiya, Meenakshi A. Chellaia Jan 2010

Regulation Of Sealing Ring Formation By L-Plastin And Cortactin In Osteoclasts, Tao Ma, Kavitha Sadashivalah, Nandakumar Madayiputhiya, Meenakshi A. Chellaia

Department of Biochemistry: Faculty Publications

The aim of this study is to identify the exact mechanism(s) by which cytoskeletal structures are modulated during bone resorption. In this study, we have shown the possible role of different actin-binding and signaling proteins in the regulation of sealing ring formation. Our analyses have demonstrated a significant increase in cortactin and a corresponding decrease in L-plastin protein levels in osteoclasts subjected to bone resorption for 18 h in the presence of RANKL, M-CSF, and native bone particles. Time-dependent changes in the localization of L-plastin (in actin aggregates) and cortactin (in the sealing ring) suggest that these proteins may be …


Structural Basis For Feedback And Pharmacological Inhibition Of Saccharomyces Cerevisiae Glutamate Cysteine Ligase, Ekaterina I Biterova, Joseph J. Barycki Jan 2010

Structural Basis For Feedback And Pharmacological Inhibition Of Saccharomyces Cerevisiae Glutamate Cysteine Ligase, Ekaterina I Biterova, Joseph J. Barycki

Department of Biochemistry: Faculty Publications

Structural characterization of glutamate cysteine ligase (GCL), the enzyme that catalyzes the initial, rate-limiting step in glutathione biosynthesis, has revealed many of the molecular details of substrate recognition. To further delineate the mechanistic details of this critical enzyme, we have determined the structures of two inhibited forms of Saccharomyces cerevisiae GCL (ScGCL), which shares significant sequence identity with the human enzyme. In vivo, GCL activity is feedback regulated by glutathione. Examination of the structure of ScGCL-glutathione complex (2.5 A ; R = 19.9%, Rfree = 25.1%) indicates that the inhibitor occupies both the glutamate- and the presumed cysteine- …


Cug Start Codon Generates Thioredoxin/Glutathione Reductase Isoforms In Mouse Testes, Maxim Gerashchenko, Dan Su, Vadim Gladyshev Jan 2010

Cug Start Codon Generates Thioredoxin/Glutathione Reductase Isoforms In Mouse Testes, Maxim Gerashchenko, Dan Su, Vadim Gladyshev

Department of Biochemistry: Faculty Publications

Mammalian cytosolic and mitochondrial thioredoxin reductases are essential selenocysteine-containing enzymes that control thioredoxin functions. Thioredoxin/glutathione reductase (TGR) is a third member of this enzyme family. It has an additional glutaredoxin domain and shows highest expression in testes. Herein, we found that human and several other mammalian TGR genes lack any AUG codons that could function in translation initiation. Although mouse and rat TGRs have such codons, we detected protein sequences upstream of them by immunoblot assays and direct proteomic analyses. Further gene engineering and expression analyses demonstrated that a CUG codon, located upstream of the sequences previously thought to initiate …


Structure Of The Proline Utilization A Proline Dehydrogenase Domain Inactivated By N-Propargylglycine Provides Insight Into Conformational Changes Induced By Substrate Binding And Flavin Reduction, Dhiraj Srivastava, Weidong Zhu, William H. Johnson Jr., Christian P. Whitman, Donald F. Becker, John J. Tanner Jan 2010

Structure Of The Proline Utilization A Proline Dehydrogenase Domain Inactivated By N-Propargylglycine Provides Insight Into Conformational Changes Induced By Substrate Binding And Flavin Reduction, Dhiraj Srivastava, Weidong Zhu, William H. Johnson Jr., Christian P. Whitman, Donald F. Becker, John J. Tanner

Department of Biochemistry: Faculty Publications

Proline utilization A (PutA) from Escherichia coli is a flavoprotein that has mutually exclusive roles as a transcriptional repressor of the put regulon and a membrane-associated enzyme that catalyzes the oxidation of proline to glutamate. Previous studies have shown that the binding of proline in the proline dehydrogenase (PRODH) active site and subsequent reduction of the FAD trigger global conformational changes that enhance PutA-membrane affinity. These events cause PutA to switch from its repressor to enzymatic role, but the mechanism by which this signal is propagated from the active site to the distal membrane-binding domain is largely unknown. Here, it …


Analysis Of Leigh Syndrome Mutations In The Yeast Surf1 Homolog Reveals A New Member Of The Cytochrome Oxidase Assembly Factor Family, Megan Bestwick, Mi-Young Jeong, Oleh Khalimonchuk, Hyung Kim, Dennis R. Winge Jan 2010

Analysis Of Leigh Syndrome Mutations In The Yeast Surf1 Homolog Reveals A New Member Of The Cytochrome Oxidase Assembly Factor Family, Megan Bestwick, Mi-Young Jeong, Oleh Khalimonchuk, Hyung Kim, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Three missense SURF1 mutations identified in patients with Leigh syndrome (LS) were evaluated in the yeast homolog Shy1 protein. Introduction of two of the Leigh mutations, F249T and Y344D, in Shy1 failed to significantly attenuate the function of Shy1 in cytochrome c oxidase (CcO) biogenesis as seen with the human mutations. In contrast, a G137E substitution in Shy1 results in a nonfunctional protein conferring a CcO deficiency. The G137E Shy1 mutant phenocopied shy1 Δ cells in impaired Cox1 hemylation and low mitochondrial copper. A genetic screen for allele-specific suppressors of the G137E …


Formation Of The Redox Cofactor Centers During Cox1 Maturation In Yeast Cytochrome Oxidase, Oleh Khalimonchuk, Megan Bestwick, Brigitte Meunier, Talina C. Watts, Dennis R. Winge Jan 2010

Formation Of The Redox Cofactor Centers During Cox1 Maturation In Yeast Cytochrome Oxidase, Oleh Khalimonchuk, Megan Bestwick, Brigitte Meunier, Talina C. Watts, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The biogenesis of cytochrome c oxidase initiates with synthesis and maturation of the mitochondrionencoded Cox1 subunit prior to the addition of other subunits. Cox1 contains redox cofactors, including the low-spin heme a center and the heterobimetallic heme a3:CuB center. We sought to identify the step in the maturation of Cox1 in which the redox cofactor centers are assembled. Newly synthesized Cox1 is incorporated within one early assembly intermediate containing Mss51 in Saccharomyces cerevisiae. Subsequent Cox1 maturation involves the progression to downstream assembly intermediates involving Coa1 and Shy1. We show that the two heme a cofactor sites …