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

Biochemistry, Biophysics, and Structural Biology Commons

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

Biotechnology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 811 - 840 of 902

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Regulated Expression Of Adenoviral Vectors-Based Gene Therapies: Therapeutic Expression Of Toxins And Immune-Modulators, James Curtin, Marianela Candolfi, Mariana Puntel, Weidong Xiong, Akm Ghulam Muhammad, Kurt Kroeger, Sonali Mondkar, Chunyan Liu, Niyati Bondale, Pedro Lowenstein, Maria Castro Jan 2008

Regulated Expression Of Adenoviral Vectors-Based Gene Therapies: Therapeutic Expression Of Toxins And Immune-Modulators, James Curtin, Marianela Candolfi, Mariana Puntel, Weidong Xiong, Akm Ghulam Muhammad, Kurt Kroeger, Sonali Mondkar, Chunyan Liu, Niyati Bondale, Pedro Lowenstein, Maria Castro

Articles

Regulatable promoter systems allow gene expression to be tightly controlled in vivo. This is highly desirable for the development of safe, efficacious adenoviral vectors that can be used to treat human diseases in the clinic. Ideally, regulatable cassettes should have minimal gene expression in the "OFF" state, and expression should quickly reach therapeutic levels in the "ON" state. In addition, the components of regulatable cassettes should be non-toxic at physiological concentrations and should not be immunogenic, especially when treating chronic illness that requires long-lasting gene expression. In this chapter, we will describe in detail protocols to develop and validate first …


Mapping The Functional Interaction Of Sco1 And Cox2 In Cytochrome Oxidase Biogenesis, Kevin Rigby, Paul A. Cobine, Oleh Khalimonchuk, Dennis R. Winge Jan 2008

Mapping The Functional Interaction Of Sco1 And Cox2 In Cytochrome Oxidase Biogenesis, Kevin Rigby, Paul A. Cobine, Oleh Khalimonchuk, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Sco1 is implicated in the copper metallation of the CuA site in

Cox2 of cytochrome oxidase. The structure of Sco1 in the metallated

and apo-conformers revealed structural dynamics primarily

in an exposed region designated loop 8. The structural

dynamics of loop 8 in Sco1 suggests it may be an interface for

interactions with Cox17, the Cu(I) donor and/or Cox2. A series

of conserved residues in the sequence motif 217KKYRVYF223 on

the leading edge of this loop are shown presently to be important

for yeast Sco1 function. Cells harboring Y219D, R220D, V221D,

and Y222D mutant Sco1 proteins failed …


Function And Redox State Of Mitochondrial Localized Cysteine-Rich Proteins Important In The Assembly Of Cytochrome C Oxidase, Oleh Khalimonchuk, Dennis R. Winge Jan 2008

Function And Redox State Of Mitochondrial Localized Cysteine-Rich Proteins Important In The Assembly Of Cytochrome C Oxidase, Oleh Khalimonchuk, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The cytochrome c oxidase (CcO) complex of the mitochondrial respiratory chain exists within the mitochondrial inner membrane (IM). The biogenesis of the complex is a multi-faceted process requiring multiple assembly factors that function on both faces of the IM. Formation of the two copper centers of CcO occurs within the intermembrane space (IMS) and is dependent on assembly factors with critical cysteinyl thiolates. Two classes of assembly factors exist, one group being soluble IMS proteins and the second class being proteins tethered to the IM. A common motif in the soluble assembly factors is a duplicated Cx9C sequence …


Pet191 Is A Cytochrome C Oxidase Assembly Factor In Saccharomyces Cerevisiae, Oleh Khalimonchuk, Kevin Rigby, Megan Bestwick, Fabien Pierrel, Paul A. Cobine, Dennis R. Winge Jan 2008

Pet191 Is A Cytochrome C Oxidase Assembly Factor In Saccharomyces Cerevisiae, Oleh Khalimonchuk, Kevin Rigby, Megan Bestwick, Fabien Pierrel, Paul A. Cobine, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The twin-Cx9C motif protein Pet191 is essential for cytochrome c oxidase maturation. The motif Cys residues are functionally important and appear to be present in disulfide linkages within a large oligomeric complex associated with the mitochondrial inner membrane. The import of Pet191 differs from that of other twin-Cx9C motif class of proteins in being independent of the Mia40 pathway.


Coa2 Is An Assembly Factor For Yeast Cytochrome C Oxidase Biogenesis That Facilitates The Maturation Of Cox1, Fabien Pierrel, Oleh Khalimonchuk, Paul A. Cobine, Megan Bestwick, Dennis R. Winge Jan 2008

Coa2 Is An Assembly Factor For Yeast Cytochrome C Oxidase Biogenesis That Facilitates The Maturation Of Cox1, Fabien Pierrel, Oleh Khalimonchuk, Paul A. Cobine, Megan Bestwick, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The assembly of cytochrome c oxidase (CcO) in yeast mitochondria is dependent on a new assembly factor designated Coa2. Coa2 was identified from its ability to suppress the respiratory deficiency of coa1 Δ and shy1 Δ cells. Coa1 and Shy1 function at an early step in maturation of the Cox1 subunit of CcO. Coa2 functions downstream of the Mss51-Coa1 step in Cox1 maturation and likely concurrent with the Shy1-related heme a3 insertion into Cox1. Coa2 interacts with Shy1. Cells lacking Coa2 show a rapid degradation of newly synthesized Cox1. Rapid Cox1 proteolysis also occurs in shy1 Δ cells, suggesting …


Purification From Human Milk Of Matriptase Complexes With Secreted Serpins: Mechanism For Inhibition Of Matriptase Other Than Hai-1, I-Chu Tseng, Feng-Pai Chou, Sheng-Feng Su, Michael Oberst, Nandakumar Madayiputhiya, Ming-Shyue Lee, Jehng-Kang Wang, David E. Sloane, Michael Johnson, Chen-Yong Lin Jan 2008

Purification From Human Milk Of Matriptase Complexes With Secreted Serpins: Mechanism For Inhibition Of Matriptase Other Than Hai-1, I-Chu Tseng, Feng-Pai Chou, Sheng-Feng Su, Michael Oberst, Nandakumar Madayiputhiya, Ming-Shyue Lee, Jehng-Kang Wang, David E. Sloane, Michael Johnson, Chen-Yong Lin

Department of Biochemistry: Faculty Publications

Matriptase, a type 2 transmembrane serine protease, is predominately expressed by epithelial and carcinoma cells in which hepatocyte growth factor activator inhibitor 1 (HAI-1), a membrane-bound, Kunitz-type serine protease inhibitor, is also expressed. HAI-1 plays dual roles in the regulation of matriptase, as a conventional protease inhibitor and as a factor required for zymogen activation of matriptase. As a consequence, activation of matriptase is immediately followed by HAI-1-mediated inhibition, with the activated matriptase being sequestered into HAI-1 complexes. Matriptase is also expressed by peripheral blood leukocytes, such as monocytes and macrophages; however, in contrast to epithelial cells, monocytes and macrophages …


High-Throughput Screening For Fatty Acid Uptake Inhibitors In Humanized Yeast Identifies Atypical Antipsychotic Drugs That Cause Dyslipidemias, Hong Li, Paul N. Black, Aalap Chokshi, Angel Sandoval-Alvarez, Ravi Vatsyayan, Whitney Sealls, Concetta Dirusso Oct 2007

High-Throughput Screening For Fatty Acid Uptake Inhibitors In Humanized Yeast Identifies Atypical Antipsychotic Drugs That Cause Dyslipidemias, Hong Li, Paul N. Black, Aalap Chokshi, Angel Sandoval-Alvarez, Ravi Vatsyayan, Whitney Sealls, Concetta Dirusso

Department of Biochemistry: Faculty Publications

Fatty acids are implicated in the development of dyslipidemias, leading to type 2 diabetes and cardiovascular disease. We used a standardized small compound library to screen humanized yeast to identify compounds that inhibit fatty acid transport protein (FATP)-mediated fatty acid uptake into cells. This screening procedure used live yeast cells expressing human FATP2 to identify small compounds that reduced the import of a fluorescent fatty acid analog, 4,4-difluoro-5-methyl-4-bora-3a,4a-diaza-s-indacene-3-dodecanoic acid (C1-BODIPY-C12). The library used consisted of 2,080 compounds with known biological activities. Of these, ~1.8% reduced cell-associated C1-BODIPY-C12 fluorescence and were selected as potential inhibitors of human FATP2- mediated fatty acid …


Water. New Waters And New Life, Juan Enriquez Jul 2007

Water. New Waters And New Life, Juan Enriquez

New England Journal of Public Policy

An excerpt from an article about life sciences taken from the proceedings of the Education for Public Inquiry and International Citizenship (EPIIC) Symposium held at Tufts University in Massachusetts in February 2005 is presented.


Optimization Of Cutaneous Electrically Mediated Plasmid Dna Delivery Using Novel Electrode, L. C. Heller, M. J. Jaroszeski, D. Coppola, A. N. Mccray, J. Hickey, R. Heller Feb 2007

Optimization Of Cutaneous Electrically Mediated Plasmid Dna Delivery Using Novel Electrode, L. C. Heller, M. J. Jaroszeski, D. Coppola, A. N. Mccray, J. Hickey, R. Heller

Bioelectrics Publications

The easy accessibility of skin makes it an excellent target for gene transfer protocols. To take advantage of skin as a target for gene transfer, it is important to establish an efficient and reproducible delivery system. Electroporation is an established technique for enhancing plasmid delivery to many tissues in vivo. A critical component of this technique is the electrode configuration. Electroporation parameters were optimized for transgene expression with minimal tissue damage with a novel electrode. The highest transgene expression and efficiency of individual cell transformation with minimal damage was produced with eight 150 ms pulses at field strength of …


Selective Cholesterol Dynamics Between Lipoproteins And Caveolae/Lipid Rafts, Stephen M. Storey, Adalberto M. Gallegos, Barbara P. Atshaves, Avery L. Mcintosh, Gregory G. Martin, Rebecca D. Parr, Kerstin K. Landrock, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder Jan 2007

Selective Cholesterol Dynamics Between Lipoproteins And Caveolae/Lipid Rafts, Stephen M. Storey, Adalberto M. Gallegos, Barbara P. Atshaves, Avery L. Mcintosh, Gregory G. Martin, Rebecca D. Parr, Kerstin K. Landrock, Ann B. Kier, Judith M. Ball, Friedhelm Schroeder

Faculty Publications

Although low-density lipoprotein (LDL) receptor-mediated cholesterol uptake through clathrin-coated pits is now well understood, the molecular details and organizing principles for selective cholesterol uptake/efflux (reverse cholesterol transport, RCT) from peripheral cells remain to be resolved. It is not yet completely clear whether RCT between serum lipoproteins and the plasma membrane occurs primarily through lipid rafts/caveolae or from non-raft domains. To begin to address these issues, lipid raft/caveolae-, caveolae-, and non-raft-enriched fractions were resolved from purified plasma membranes isolated from L-cell fibroblasts and MDCK cells by detergent-free affinity chromatography and compared with detergent-resistant membranes isolated from the same cells. Fluorescent sterol …


A New Strategy For Assessing Selenoprotein Function: Sirna Knockdown/Knock-In Targeting The 3'-Utr, Min-Hyuk Yoo, Xue-Ming Xu, Anton A. Turanov, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield Jan 2007

A New Strategy For Assessing Selenoprotein Function: Sirna Knockdown/Knock-In Targeting The 3'-Utr, Min-Hyuk Yoo, Xue-Ming Xu, Anton A. Turanov, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield

Department of Biochemistry: Faculty Publications

Selenocysteine insertion into protein in mammalian cells requires RNA elements in the 3'-untranslated regions (3'-UTRs) of selenoprotein genes. The occurrence of these conserved sequences should make selenoproteins particularly amenable for knockdown/knock-in strategies to examine selenoprotein functions. Herein, we utilized the 3'-UTR of various selenoproteins to knock down their expression using siRNAs and then knock in expression using constructs containing mutations within the target region. Thioredoxin reductase 1 (TR1) knockdown in a mouse kidney cell line resulted in the cells growing about 10% more slowly, being more sensitive to UV radiation, and having increased apoptosis in response to UV than control …


Mechanistic Studies Of The Long Chain Acyl-Coa Synthetase Faa1p From Saccharomyces Cerevisiae, Hong Li, Elaina M. Melton, Steven Quackenbush, Concetta C. Dirusso, Paul N. Black Jan 2007

Mechanistic Studies Of The Long Chain Acyl-Coa Synthetase Faa1p From Saccharomyces Cerevisiae, Hong Li, Elaina M. Melton, Steven Quackenbush, Concetta C. Dirusso, Paul N. Black

Department of Biochemistry: Faculty Publications

Long chain acyl-CoA synthetase (ACSL; fatty acid CoA ligase: AMP forming; EC 6.2.1.3) catalyzes the formation of acyl-CoA through a process, which requires fatty acid, ATP and coenzymeA as substrates. In the yeast Saccharomyces cerevisiae the principal ACSL is Faa1p (encoded by the FAA1 gene). The preferred substrates for this enzyme are cis-monounsaturated long chain fatty acids. Our previous work has shown Faa1p is a principal component of a fatty acid transport/activation complex that also includes the fatty acid transport protein Fat1p. In the present work hexameric histidine tagged Faa1p was purified to homogeneity through a two-step process in the …


Evidence For A Pro-Oxidant Intermediate In The Assembly Of Cytochrome Oxidase, Oleh Khalimonchuk, Amanda Bird, Dennis R. Winge Jan 2007

Evidence For A Pro-Oxidant Intermediate In The Assembly Of Cytochrome Oxidase, Oleh Khalimonchuk, Amanda Bird, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The hydrogen peroxide sensitivity of cells lacking two proteins,

Sco1 and Cox11, important in the assembly of cytochrome

c oxidase (CcO), is shown to arise from the transient accumulation

of a pro-oxidant heme A-Cox1 stalled intermediate. The

peroxide sensitivity of these cells is abrogated by a reduction in

either Cox1 expression or hemeAformation but exacerbated by

either enhanced Cox1 expression or heme A production arising

from overexpression of COX15. Sco1 and Cox11 are implicated

in the formation of the CuA and CuB sites of CcO, respectively.

The respective wild-type genes suppress the peroxide sensitivities

of sco1∆ …


Coa1 Links The Mss51 Post-Translational Function To Cox1 Cofactor Insertion In Cytochrome C Oxidase Assembly, Fabien Pierrel, Megan L. Bestwick, Paul A. Cobine, Oleh Khalimonchuk, Julia A. Cricco, Dennis R. Winge Jan 2007

Coa1 Links The Mss51 Post-Translational Function To Cox1 Cofactor Insertion In Cytochrome C Oxidase Assembly, Fabien Pierrel, Megan L. Bestwick, Paul A. Cobine, Oleh Khalimonchuk, Julia A. Cricco, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The assembly of cytochrome c oxidase (CcO) in yeast mitochondria is shown to be dependent on a new assembly factor designated Coa1 that associates with the mitochondrial inner membrane. Translation of the mitochondrial-encoded subunits of CcO occurs normally in coa1Δ cells, but these subunits fail to accumulate. The respiratory defect in coa1Δ cells is suppressed by high-copy MSS51, MDJ1 and COX10. Mss51 functions in Cox1 translation and elongation, whereas Cox10 participates in the biosynthesis of heme a, a key cofactor of CcO. Respiration in coa1Δ and shy1Δ cells is enhanced when Mss51 and …


Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall May 2006

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …


In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng May 2006

In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng

Honors Scholar Theses

The major histocompatibility complex (MHC) is a gene family responsible for many critical functions of the immune system in most vertebrates. The MHC consists of three classes differentiated by their structure and function, and MHC class I encodes antigen binding proteins as well as chaperone and accessory proteins such as tapasin. The purpose of this project is to reconstitute several human MHC class I molecules in their peptide-filled and peptide-deficient forms, and to purify these proteins for biochemical study. The expressed proteins include wild type and mutant variants of the fusion protein human leukocyte antigen HLA-B*0801-fos, and human beta-2-microglobulin (β2m). …


Evaluation Of Toxicity Following Electrically Mediated Interleukin-12 Gene Delivery In A B16 Mouse Melanoma Model, Loree Heller, Kathleen Merkler, Jeffrey Westover, Yolmari Cruz, Domenico Coppola, Kaaron Benson, Adil Daud, Richard Heller May 2006

Evaluation Of Toxicity Following Electrically Mediated Interleukin-12 Gene Delivery In A B16 Mouse Melanoma Model, Loree Heller, Kathleen Merkler, Jeffrey Westover, Yolmari Cruz, Domenico Coppola, Kaaron Benson, Adil Daud, Richard Heller

Bioelectrics Publications

PURPOSE: Interleukin-12 (IL-12) has potential as an immunotherapeutic agent for the treatment of cancer but is unfortunately associated with toxicity. Delivery of a plasmid encoding IL-12 with electroporation induces an antitumor effect in the B16 mouse melanoma model without serious side effects. To translate this observation to the clinic, an evaluation of toxicity was done in the mouse model.

EXPERIMENTAL DESIGN: Weight change, tumor response, blood chemistry and hematology values, and serum IL-12 levels were evaluated. Multiple tissues were analyzed histopathologically.

RESULTS: A pronounced reduction in tumor volume, including a large percentage of complete regressions, was observed after electrically mediated …


Characterization Of Vinyl Chloride Degrading Bacteria From A Serial Anaerobic-Aerobic Chloroethene Bioreactor, Fredrick Heath Damron Jan 2006

Characterization Of Vinyl Chloride Degrading Bacteria From A Serial Anaerobic-Aerobic Chloroethene Bioreactor, Fredrick Heath Damron

Theses, Dissertations and Capstones

Chloroethenes are among the most common groundwater contaminants in the United States. In anoxic groundwater, chloroethenes can be reduced to vinyl chloride (VC), a known carcinogen. The goal of this research was to characterize bacteria that could mineralize VC from a microbial community within a serial aerobic-anaerobic chloroethene bioreactor. Isolations for organisms capable of VC degradation were performed. The ability to degrade VC was first indicated by accumulation of chloride. Gas chromatography assay showed that VC was degraded in cultures capable of chloride accumulation. The epoxyalkane:coenzyme M transferase (EaCoMT) gene which codes for an enzyme previously shown to function in …


Plasma Membrane Voltage Changes During Nanosecond Pulsed Electric Field Exposure, W. Frey, R. O. Price, P. F. Blackmore, R. P. Joshi, R. Nuccitelli, S. J. Beebe, K. H. Schoenbach, J. F. Kolb Jan 2006

Plasma Membrane Voltage Changes During Nanosecond Pulsed Electric Field Exposure, W. Frey, R. O. Price, P. F. Blackmore, R. P. Joshi, R. Nuccitelli, S. J. Beebe, K. H. Schoenbach, J. F. Kolb

Bioelectrics Publications

The change in the membrane potential of Jurkat cells in response to nanosecond pulsed electric fields was studied for pulses with a duration of 60 ns and maximum field strengths of similar to 100 kV/cm (100 V/cell diameter). Membranes of Jurkat cells were stained with a fast voltage-sensitive dye, ANNINE-6, which has a subnanosecond voltage response time. A temporal resolution of 5 ns was achieved by the excitation of this dye with a tunable laser pulse. The laser pulse was synchronized with the applied electric field to record images at times before, during, and after exposure. When exposing the Jurkat …


Sequential Processing Of A Mitochondrial Tandem Protein: Insights Into Protein Import In Schizosaccharomyces Pombe, Oleh Khalimonchuk, Martin Ott, Soledad Funes, Kai Ostermann, Gerhard Rödel, Johannes M. Herrmann Jan 2006

Sequential Processing Of A Mitochondrial Tandem Protein: Insights Into Protein Import In Schizosaccharomyces Pombe, Oleh Khalimonchuk, Martin Ott, Soledad Funes, Kai Ostermann, Gerhard Rödel, Johannes M. Herrmann

Department of Biochemistry: Faculty Publications

The sequencing of the genome of Schizosaccharomyces pombe revealed the presence of a number of genes encoding tandem proteins, some of which are mitochondrial components. One of these proteins (pre-Rsm22- Cox11) consists of a fusion of Rsm22, a component of the mitochondrial ribosome, and Cox11, a factor required for copper insertion into cytochrome oxidase. Since in Saccharomyces cerevisiae, Cox11 is physically attached to the mitochondrial ribosome, it was suggested that the tandem organization of Rsm22-Cox11 is used to covalently tie the mitochondrial ribosome to Cox11 in S. pombe. We report here that pre-Rsm22-Cox11 is matured in two subsequent …


Purification And Initial Biochemical Characterization Of Atp:Cob(I)Alamin Adenosyltransferase (Eutt) Enzyme Of Salmonella Enterica, Nicole R. Baun, Jorge C. Escalante-Semerena Jan 2006

Purification And Initial Biochemical Characterization Of Atp:Cob(I)Alamin Adenosyltransferase (Eutt) Enzyme Of Salmonella Enterica, Nicole R. Baun, Jorge C. Escalante-Semerena

Department of Biochemistry: Faculty Publications

ATP:cob(I)alamin adenosyltransferase (EutT) of Salmonella

enterica was overproduced and enriched to ~70% homogeneity,

and its basic kinetic parameters were determined. Abundant

amounts of EutT protein were produced, but all of it remained

insoluble. Soluble active EutT protein (~70% homogeneous) was

obtained after treatment with detergent. Under conditions in which

cobalamin (Cbl) was saturating, Km(ATP) = 10 µM, kcat = 0.03 s-1,

and Vmax = 54.5 nM min-1. Similarly, under conditions in which

MgATPwas saturating,Km(Cbl) = 4.1µM, kcat = 0.06 s-1, andVmax= …


Computer-Assisted Docking Of Flavodoxin With The Atp:Co(I)Rrinoid Adenosyltransferase (Coba) Enzyme Reveals Residues Critical For Protein-Protein Interactions But Not For Catalysis*, Nicole R. Buan, Jorge C. Escalante-Semerena Dec 2005

Computer-Assisted Docking Of Flavodoxin With The Atp:Co(I)Rrinoid Adenosyltransferase (Coba) Enzyme Reveals Residues Critical For Protein-Protein Interactions But Not For Catalysis*, Nicole R. Buan, Jorge C. Escalante-Semerena

Department of Biochemistry: Faculty Publications

The activity of the housekeeping ATP:co(I)rrinoid adenosyltransferase (CobA) enzyme of Salmonella enterica sv. Typhimurium is required to adenosylate de novo biosynthetic intermediates of adenosylcobalamin and to salvage incomplete and complete corrinoids from the environment of this bacterium. In vitro, reduced flavodoxin (FldA) provides an electron to generate the co(I)rrinoid substrate in the CobA active site. To understand how CobAand FldA interact, a computer model of aCobA∙FldA complex was generated. This model was used to guide the introduction of mutations into CobA using site-directed mutagenesis and the synthesis of a peptide mimic of FldA. Residues Arg-9 and Arg-165 of CobA …


Selective Field Effects On Intracellular Vacuoles And Vesicle Membranes With Nanosecond Electric Pulses, Ephrem Tekle, Hammou Oubrahim, Sergey M. Dzekunov, Juergen F. Kolb, Karl H. Schoenbach Jan 2005

Selective Field Effects On Intracellular Vacuoles And Vesicle Membranes With Nanosecond Electric Pulses, Ephrem Tekle, Hammou Oubrahim, Sergey M. Dzekunov, Juergen F. Kolb, Karl H. Schoenbach

Bioelectrics Publications

Electric pulses across intact vesicles and cells can lead to transient increase in permeability of their membranes. We studied the integrity of these membranes in response to external electric pulses of high amplitude and submicrosecond duration with a primary aim of achieving selective permeabilization. These effects were examined in two separate model systems comprising of 1), a mixed population of 1,2-di-oleoyl-sn-glycero-3-phosphocholine phospholipid vesicles and in 2), single COS-7 cells, in which large endosomal membrane vacuoles were induced by stimulated endocytosis. It has been shown that large and rapidly varying external electric fields, with pulses shorter than the charging time of …


Computer-Assisted Docking Of Flavodoxin With The Atp:Co(I)Rrinoid Adenosyltransferase (Coba) Enzyme Reveals Residues Critical For Protein-Protein Interactions But Not For Catalysis, Nicole R. Baun, Jorge C. Escalante-Semerena Jan 2005

Computer-Assisted Docking Of Flavodoxin With The Atp:Co(I)Rrinoid Adenosyltransferase (Coba) Enzyme Reveals Residues Critical For Protein-Protein Interactions But Not For Catalysis, Nicole R. Baun, Jorge C. Escalante-Semerena

Department of Biochemistry: Faculty Publications

The activity of the housekeeping ATP:co(I)rrinoid adenosyltransferase

(CobA) enzyme of Salmonella enterica sv. Typhimurium

is required to adenosylate de novo biosynthetic intermediates

of adenosylcobalamin and to salvage incomplete and complete

corrinoids from the environment of this bacterium. In vitro,

reduced flavodoxin (FldA) provides an electron to generate the

co(I)rrinoid substrate in the CobA active site. To understand how

CobAand FldA interact, a computer model of aCobA-FldA complex

was generated. This model was used to guide the introduction of

mutations into CobA using site-directed mutagenesis and the synthesis

of a peptide mimic of FldA. Residues Arg-9 and Arg-165 of

CobA …


Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper Jan 2005

Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

This study addresses how humic substance (HS) chemical composition and photoreactivity affect bacterial growth, respiration, and growth efficiency (BGE) in lake water. Aqueous solutions of HSs from diverse aquatic environments representing different dissolved organic matter sources (autochthonous and allochthonous) were exposed to artificial solar UV radiation. These solutions were added to lake water passed through a 0.7-μm pore-size filter (containing grazer-free lake bacteria) followed by dark incubation for 5, 43, and 65 h. For the 5-h incubation, several irradiated HSs inhibited bacterial carbon production (BCP) and this inhibition was highly correlated with H2O2 photoproduction. The H2 …


On Thacker's Biomedia (2004), Nicholas Ruiz Iii Oct 2004

On Thacker's Biomedia (2004), Nicholas Ruiz Iii

Reconstruction: Studies in Contemporary Culture

[First paragraph]

Only we could have done it. The Code (DNA and its analogs, etc.) that we perhaps only narrate, never forgetting all of the fictions that narration portends, today consciously edits the text that evolution has edited unconsciously for eons. Thacker considers how humans -- perhaps little more than interactive Code, manipulate the Code -- with the technology of the Code. No other faction of Code has yet to make such heady ‘gains.’ Where posthumanity was always a literary endeavor, a literary bypass, out of instrumental science and into fictive states, it now is a technical endeavor, encompassing a …


The Identity Of Proteins Associated With A Small Heat Shock Protein During Heat Stress In Vivo Indicates That These Chaperones Protect A Wide Range Of Cellular Functions, Eman Basha, Garrett J. Lee, Linda A. Breci, Andrew C. Hausrath, Nicole R. Buan, Kim C. Giese, Elizabeth Vierling Feb 2004

The Identity Of Proteins Associated With A Small Heat Shock Protein During Heat Stress In Vivo Indicates That These Chaperones Protect A Wide Range Of Cellular Functions, Eman Basha, Garrett J. Lee, Linda A. Breci, Andrew C. Hausrath, Nicole R. Buan, Kim C. Giese, Elizabeth Vierling

Department of Biochemistry: Faculty Publications

The small heat shock proteins (sHSPs) are a ubiquitous class of ATP-independent chaperones believed to prevent irreversible protein aggregation and to facilitate subsequent protein renaturation in cooperation with ATP-dependent chaperones. Although sHSP chaperone activity has been studied extensively in vitro, understanding the mechanism of sHSP function requires identification of proteins that are sHSP substrates in vivo. We have used both immunoprecipitation and affinity chromatography to recover 42 proteins that specifically interact with Synechocystis Hsp16.6 in vivo during heat treatment. These proteins can all be released from Hsp16.6 by the ATP-dependent activity of DnaK and cochaperones and are heat-labile. Thirteen …


Interactions Between Small Heat Shock Protein Subunits And Substrate In Small Heat Shock Protein-Substrate Complexes, Kenneth L. Friedrich, Kim C. Giese, Nicole R. Baun, Elizabeth Vierling Jan 2004

Interactions Between Small Heat Shock Protein Subunits And Substrate In Small Heat Shock Protein-Substrate Complexes, Kenneth L. Friedrich, Kim C. Giese, Nicole R. Baun, Elizabeth Vierling

Department of Biochemistry: Faculty Publications

Small heat shock proteins (sHSPs) are dynamic oligomeric

proteins that bind unfolding proteins and protect

them from irreversible aggregation. This binding results

in the formation of sHSP-substrate complexes from

which substrate can later be refolded. Interactions between

sHSP and substrate in sHSP-substrate complexes

and the mechanism by which substrate is transferred to

ATP-dependent chaperones for refolding are poorly defined.

We have established C-terminal affinity-tagged

sHSPs from a eukaryote (pea HSP18.1) and a prokaryote

(Synechocystis HSP16.6) as tools to investigate these issues.

We demonstrate that sHSP subunit exchange for

HSP18.1 and HSP16.6 is temperature-dependent and

rapid at the optimal growth …


The Identity Of Proteins Associated With A Small Heat Shock Protein During Heat Stress In Vivo Indicates That These Chaperones Protect A Wide Range Of Cellular Functions, Eman Basha, Garrett J. Lee, Linda A. Breci, Andrew C. Hausrath, Nicole R. Baun, Kim C. Giese, Elizabeth Vierling Jan 2004

The Identity Of Proteins Associated With A Small Heat Shock Protein During Heat Stress In Vivo Indicates That These Chaperones Protect A Wide Range Of Cellular Functions, Eman Basha, Garrett J. Lee, Linda A. Breci, Andrew C. Hausrath, Nicole R. Baun, Kim C. Giese, Elizabeth Vierling

Department of Biochemistry: Faculty Publications

The small heat shock proteins (sHSPs) are a ubiquitous

class of ATP-independent chaperones believed to

prevent irreversible protein aggregation and to facilitate

subsequent protein renaturation in cooperation

with ATP-dependent chaperones. Although sHSP chaperone

activity has been studied extensively in vitro, understanding

the mechanism of sHSP function requires

identification of proteins that are sHSP substrates in

vivo. We have used both immunoprecipitation and affinity

chromatography to recover 42 proteins that specifically

interact with Synechocystis Hsp16.6 in vivo during

heat treatment. These proteins can all be released from

Hsp16.6 by the ATP-dependent activity of DnaK and cochaperones

and are heat-labile. …


Computational Protein Biomarker Prediction: A Case Study For Prostate Cancer, Michael Wagner, Dayanand N. Naik, Alex Pothen, Srinivas Kasukurti, Raghu Ram Devineni, Bao-Ling Adam, O. John Semmes, George L. Wright Jr. Jan 2004

Computational Protein Biomarker Prediction: A Case Study For Prostate Cancer, Michael Wagner, Dayanand N. Naik, Alex Pothen, Srinivas Kasukurti, Raghu Ram Devineni, Bao-Ling Adam, O. John Semmes, George L. Wright Jr.

Mathematics & Statistics Faculty Publications

Background: Recent technological advances in mass spectrometry pose challenges in computational mathematics and statistics to process the mass spectral data into predictive models with clinical and biological significance. We discuss several classification-based approaches to finding protein biomarker candidates using protein profiles obtained via mass spectrometry, and we assess their statistical significance. Our overall goal is to implicate peaks that have a high likelihood of being biologically linked to a given disease state, and thus to narrow the search for biomarker candidates.

Results: Thorough cross-validation studies and randomization tests are performed on a prostate cancer dataset with over 300 patients, obtained …