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Articles 1 - 17 of 17

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

A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan Dec 1990

A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan

Electronic Theses and Dissertations

A temperature-sensitive mutant of Escherichia coli affected in the alpha subunit of RNA polymerase has been investigated. Gene mapping and complementation experiments placed the mutation to temperature-sensitivity within the alpha operon at 72 min on the bacterial chromosome. The rate of RNA synthesis in vivo and the accumulation of ribosomal RNA were significantly reduced in the mutant at 44$\sp\circ$C. The thermostability at 44$\sp\circ$C of the purified holoenzyme from mutant cells was about 20% of that of the normal enzyme. Assays with T7 DNA as a template showed that the fraction of active enzyme competent ...


Functional And Structural Characterization Of A Human H4 Histone Gene Promoter: A Thesis, Kenneth Lynn Wright Nov 1990

Functional And Structural Characterization Of A Human H4 Histone Gene Promoter: A Thesis, Kenneth Lynn Wright

GSBS Dissertations and Theses

Expression of the cell cycle dependent FO10S human H4 histone gene is regulated at both the transcriptional and post-transcriptional levels. We have investigated the 5' promoter elements mediating the transcriptional aspects of its regulation. A detailed in vivo and in vitro transcriptional analysis of promoter deletion mutants from this gene has identified three positive regulatory elements and two potentially negative regulatory elements within the first 1000 base pairs upstream of the transcription initiation site. In addition, the minimal promoter located within the first 70 base pairs is required for accurate transcription initiation and contains one of two in vivo identified ...


Laminin Potentiates Differentiation Of Pcc4uva Embryonal Carcinoma Into Neurons, T. M. Sweeney, Roy C. Ogle, C. D. Little Sep 1990

Laminin Potentiates Differentiation Of Pcc4uva Embryonal Carcinoma Into Neurons, T. M. Sweeney, Roy C. Ogle, C. D. Little

Medical Diagnostics & Translational Sciences Faculty Publications

The embryonal carcinoma PCC4uva differentiates into neurons in response to treatment with retinoic acid and dbcAMP. We used this in vitro model system to study the effects of laminin on early neural differentiation. Laminin substrata markedly potentiate neural differentiation of retinoic acid and dbcAMP-treated cultures. Only laminin induced more rapid neural cell body clustering, neurite growth and neurite fasciculation as compared to type IV collagen, type I collagen, and fibronectin substrata. Exogenous laminin substrata promoted greater cell attachment, cellular spreading and growth to confluence than type IV collagen, type I collagen, fibronectin and glass substrata. Laminin-induced effects were inhibited by ...


Bilirubin-Albumin Binding At Varying Conditions Of Hematocrit, Sodium Benzoate Concentration, And Bilirubin/Albumin Molar Ratios, Patrick Ahrens Apr 1990

Bilirubin-Albumin Binding At Varying Conditions Of Hematocrit, Sodium Benzoate Concentration, And Bilirubin/Albumin Molar Ratios, Patrick Ahrens

Life and Environmental Sciences Undergraduate Theses

Hyperbilirubinemia, which causes jaundice, is quite common in newborns. Typically bilirubin is bound to its carrier protein albumin and very little unbound bilirubin is present in the blood. However, in cases of hyperbilirubinemia there is a marked increase in unbound bilirubin, which can be toxic. The two methods traditionally used to treat hyperbilirubinemia are exchange transfusion and phototherapy. Each of these methods have drawbacks. The Department of Chemical, Bio, and Materials Engineering at Arizona State University is currently developing an extra-corporeal hemoperfusion column that will remove the unbound bilirubin fraction from the blood of jaundiced patients. This column utilizes coated ...


Nucleotide Sequence And Further Characterization Of The Synechococcus Sp. Strain Pcc 7002 Reca Gene: Complementation Of A Cyanobacterial Reca Mutation By The Escherichia Coli Reca Gene, R C. Murphy, G E. Gasparich, D A. Bryant, R D. Porter Jan 1990

Nucleotide Sequence And Further Characterization Of The Synechococcus Sp. Strain Pcc 7002 Reca Gene: Complementation Of A Cyanobacterial Reca Mutation By The Escherichia Coli Reca Gene, R C. Murphy, G E. Gasparich, D A. Bryant, R D. Porter

Gail Gasparich

The nucleotide sequence and transcript initiation site of the Synechococcus sp. strain PCC 7002 recA gene have been determined. The deduced amino acid sequence of the RecA protein of this cyanobacterium is 56% identical and 73% similar to the Escherichia coli RecA protein. Northern (RNA) blot analysis indicates that the Synechococcus strain PCC 7002 recA gene is transcribed as a monocistronic transcript 1,200 bases in length. The 5' endpoint of the recA mRNA was mapped by primer extension by using synthetic oligonucleotides of 17 and 27 nucleotides as primers. The nucleotide sequence 5' to the mapped endpoint contained sequence ...


Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick Jan 1990

Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick

Michael Sinensky

The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic ...


Genetic And Molecular Analyses Of Suppressor Of Forked In Drosophila Melanogaster , Cynthia Lynn Fitch-Steenson Jan 1990

Genetic And Molecular Analyses Of Suppressor Of Forked In Drosophila Melanogaster , Cynthia Lynn Fitch-Steenson

Retrospective Theses and Dissertations

Mutations at the suppressor of forked, su(f), locus are trans-acting, allele specific suppressors and enhancers of mutations at certain other loci. Su(f) is a trans-acting regulator whose normal product is necessary for proper transcription of these genes. The su(f) product regulates the transcription of transposable elements located within these genes. Our investigation includes a genetic analysis in which a number of new su(f) alleles were isolated, a development analysis in which the effects of new alleles and allelic combinations were characterized, and a molecular analysis in which a cloned genomic DNA fragment containing su(f) was ...


Molecular Characterization Of The Yeast Gene Hsp60 , Donald Stevenson Reading Jan 1990

Molecular Characterization Of The Yeast Gene Hsp60 , Donald Stevenson Reading

Retrospective Theses and Dissertations

In all organisms studied, heat shock or other stressful stimuli lead to profound changes in gene expression. During heat shock, a small group of evolutionarily conserved proteins, termed heat shock proteins (hsps), are synthesized in abunDance; Several hsps are known to have vital cellular function even at normal temperature. These hsps have the capacity to bind polypeptide chains and have a probable role in the folding, translocation, and assembly pathways of many proteins. One such protein, hsp60, is located within mitochondria, is highly conserved in evolution, and based on immunological and physical characterization, is a member of a family of ...


Cell-Wall Components And Lignin Biosynthesis In Forages , James Enderby Bidlack Jan 1990

Cell-Wall Components And Lignin Biosynthesis In Forages , James Enderby Bidlack

Retrospective Theses and Dissertations

Lignin is the major cell-wall (CW) component that lowers forage digestibility. Negative relationships between lignin and forage quality are caused by interactions and variability of lignin with other CW components. This study was conducted to better understand how lignin content, concentration, deposition, and change in concentration vary with other CW components in maturing stems and to provide preliminary information about phenylpropanoid metabolism in relation to lignification;Regrowth from basal stem tissue was sampled weekly or biweekly from greenhouse-grown forage grass and legume species. Samples were collected for a period of about 8 weeks and analyzed for fiber concentration and content ...


Regulation Of Protein Expression By Transforming Growth Factor Beta And Other Growth Modulators , Frederic William Thalacker Jan 1990

Regulation Of Protein Expression By Transforming Growth Factor Beta And Other Growth Modulators , Frederic William Thalacker

Retrospective Theses and Dissertations

The main goal of this project was to understand the signal transduction pathways through which growth modulators such as TGF-[beta], PMA and retinoic acid mediate protein expression and DNA synthesis. Transforming growth factor [beta] (TGF-[beta]) induces synthesis and secretion of a 48,000 M r protein that we have found to be type I plasminogen activator inhibitor (PAI-1). TGF-[beta] induces PAI-1 in every cell line that we have studied including near term mink lung epithelial CCL64 cells, mouse embryo fibroblast AKR-2B 84A cells, African green monkey kidney epithelial BSC-1 cells, and normal rat kidney fibroblast NRK 49F ...


A Restriction Fragment Length Polymorphism Map Of Cochliobolus Heterostrophus , Tzy-Hwa Tzeng Jan 1990

A Restriction Fragment Length Polymorphism Map Of Cochliobolus Heterostrophus , Tzy-Hwa Tzeng

Retrospective Theses and Dissertations

An RFLP map was constructed for Cochliobolus heterostrophus, the causal agent of southern corn leaf blight, to facilitate the cloning of pathogenicity genes. A total of 128 RFLP and 4 phenotypic markers were analyzed. Of these, 126 were linked to other markers and delimited 944 cM, or, at a maximum, 58% of the total map length. Several RFLPs were found tightly linked to Tox1, a pathogenicity gene. A previously hypothesized translocation tightly linked to Tox1 was also detected;The numbers and sizes of the chromosomes of the two strains crossed to make the RFLP map were investigated using pulsed field ...


Isolation Of A Chicken Cardiac Muscle Titin Cdna Probe , Greg Robert Sater Jan 1990

Isolation Of A Chicken Cardiac Muscle Titin Cdna Probe , Greg Robert Sater

Retrospective Theses and Dissertations

The objective of this project was to construct and identify a cDNA probe for the striated muscle protein titin. RNA was isolated from skeletal and cardiac muscle of 16 day chicken embryos using a guanidinium isothiocyanate procedure. The RNA thus isolated was both intact (as shown by agarose gel electrophoresis) and transcribable in vitro; additionally, it was possible to obtain very large RNA molecules in this manner. cDNA was then constructed utilizing random oligodeoxynucleotides for priming of the first strand synthesis reaction, instead of the more common oligo-dT priming. Random priming was also utilized for second strand synthesis. As with ...


Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick Jan 1990

Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick

Faculty Publications

The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic ...


Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander Jan 1990

Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander

Bioelectrics Publications

Progesterone and 17 alpha-hydroxyprogesterone (but not other steroids such as testosterone, corticosterone, beta-estradiol, estrone, dehydroepiandrosterone, 20 alpha-hydroxypregnen-3-one, androstenedione, and pregnenolone) were shown to cause an immediate increase, in free cytosolic calcium ([Ca2+]i) in both capacitated and noncapacitated human sperm, using the fluorescent indicator fura 2. Significant increases in [Ca2+]i were observed with 10 ng/ml progesterone, while maximum effects were seen with 1 microgram/ml progesterone. Two other steroids 11 beta-hydroxyprogesterone and 5 alpha-pregnane-3,20-dione exhibited significant activity to increase [Ca2+]i. This increase in [Ca2+]i elicited by progesterone was entirely due to Ca2+ influx from the ...


The Crystal Structure Of Adenylosuccinate Synthetase From Escherichia Coli , Kyung Hyun Kim Jan 1990

The Crystal Structure Of Adenylosuccinate Synthetase From Escherichia Coli , Kyung Hyun Kim

Retrospective Theses and Dissertations

The crystal structure of adenylosuccinate synthetase from Eschericha coli has been pursued to a resolution of 3.7 A. Using isomorphous and anomalous (SIRAS) phases from a HgI[subscript]4[superscript]2- derivative, electron density maps were generated that clearly revealed the envelope of the enzyme dimer and the two-fold molecular symmetry of the dimer;Since the enzyme is active as a dimer consisting of two identical monomers, the method of density averaging (Bricogne, 1976) was employed to improve the electron density map based on SIRAS phases. The non-crystallographic two-fold operator, which relates two monomers, was refined against an SIRAS ...


Identification Of The Immediate-Early Products Of Bovine Herpesvirus-1 , David A. Hulce Jan 1990

Identification Of The Immediate-Early Products Of Bovine Herpesvirus-1 , David A. Hulce

Retrospective Theses and Dissertations

Bovine herpesvirus-1 (BHV-1) is a member of the alphaherpesvirinae. Productive infections of the alphaherpesvirinae progress through three stages of viral transcription and translation. The first stage, immediate-early (IE), does not require prior viral gene expression and is required for the second, delayed-early (DE), and third, late (L), stages of the infectious cycle. Like other herpesviruses, BHV-1 frequently establishes latent infections. This study was undertaken to characterize the IE stage of the productive BHV-1 infection. The number and location of IE genes and the size of IE polypeptides and IE mRNAs were investigated;Probing genomic Southern blots of BHV-1 cloned in ...


Analysis And Characterization Of The Major Histocompatibility Complex Of Domestic Animals , Yuanxin Xu Jan 1990

Analysis And Characterization Of The Major Histocompatibility Complex Of Domestic Animals , Yuanxin Xu

Retrospective Theses and Dissertations

The major histocompatibility complex (MHC) is a family of genes coding for molecules which play important roles in the immune response as well as many other cellular processes of a vertebrate organism. The understanding of the immune system of some of the domestic animals will have both practical value and theoretical significance. The purpose of this work was to study the MHC of the chicken (B) and the swine (SLA). First, in order to study the MHC class II gene structure of the chicken, a genomic library was constructed from an inbred chicken line G-B2 (MHC haplotype B[superscript]6 ...