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Articles 12031 - 12060 of 12624

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

Effects Of Dna Synthesis Inhibitors On The Induction Of Hcg Subunits And Alkaline Phosphatase In Hela S3 Cells , Kyung-Hea Cho Park Jan 1981

Effects Of Dna Synthesis Inhibitors On The Induction Of Hcg Subunits And Alkaline Phosphatase In Hela S3 Cells , Kyung-Hea Cho Park

Retrospective Theses and Dissertations

The synthesis of human chorionic gonadotropin (alpha)- and (beta)-subunits and alkaline phosphatase has been examined in HeLa S(,3) cultures. A variety of compounds which inhibit DNA synthesis lead to the increased production of PAP and the glycoprotein hormone subunits in HeLa cells. In general, compounds which influenced deoxynucleotide metabolism were good inducers of these ectopic proteins, while agents which altered DNA structure by intercalation or covalent binding were poor inducers. The greatest induction was achieved with sodium butyrate. Although a direct correlation between protein induction and DNA synthesis inhibition has not been demonstrated for all inducers, the dose-response ...


Purification And Partial Characterization Of Mitochondrial Ribosomes From A Hela Cell Line Resistant To Chloramphenicol , Kenton Stuart Miller Jan 1981

Purification And Partial Characterization Of Mitochondrial Ribosomes From A Hela Cell Line Resistant To Chloramphenicol , Kenton Stuart Miller

Retrospective Theses and Dissertations

Techniques are described for the purification of mitochondrial ribosomes from two lines of HeLa cells, S(,3) and 296-1, one of which (296-1) is resistant to chloramphenicol in vivo. The in vitro protein synthetic activity of purified mitochondrial ribosomes from both strains are compared for their sensitivity to a variety of drugs including chloramphenicol;For the preparation of mitochondrial ribosomes from either cell line, crude mitochondria are washed several times in buffer containing 0.002M EDTA, and mitoplasts are prepared by treatment with digitonin at a digitonin to mitochondrial protein ratio of 0.15. The mitoplasts are lysed by the ...


Peptidohydrolases Of Soybean Root Nodules, Nasir S. A. Malik, N. E. Pfeiffer, D. R. Williams, Fred W. Wagner Jan 1981

Peptidohydrolases Of Soybean Root Nodules, Nasir S. A. Malik, N. E. Pfeiffer, D. R. Williams, Fred W. Wagner

Biochemistry -- Faculty Publications

Nodule extracts prepared from Glycine max var Woodworth possessed endopeptidase, aminoptidase, and carboxypeptidase actiities. Three distinct endopeptidase activities could be resolved by disc-gel electrophoresis at pH 8.8. According to their order of increasing electrophoretic mobility, the first of these enzymes hydrolyzed azocasein and n-benzoyl-LLeu-β-naphthylamide, while the second hydrolyzed n-benzoyl-L-Arg-/8- naphthylamine (Bz-L-Arg-/βNA), n-benzoyl-L-Arg-β-nitroanilide (Bz-L-Arg-βNA), and azocasein. The third endopeptidase hydrolyzed Bz-L-Arg-βNA, Bz-L-Arg-βNA, and hemoglobin. Fractions of these enzymes extracted from electrophoresis gels were shown to have pH optima from 7.5 to 9.8. AU of the endopeptidases were completely inhibited by diisopropylphosphorofluoridate, demonstrating that they were serine ...


Listening In To Wildlife, Charles Amlaner, David Macdonald Dec 1980

Listening In To Wildlife, Charles Amlaner, David Macdonald

Charles J. Amlaner

No abstract provided.


Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson Dec 1980

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

Publications (WR)

This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little ...


The Effect Of Lead On Developing Rat Brain Lipids, Larry J. Stegink Dec 1980

The Effect Of Lead On Developing Rat Brain Lipids, Larry J. Stegink

Master's Theses

The objective of this study was to determine the effect of lead on the brain lipids of developing rats.

Lead acetate was added to the drinking water of two pregnant rats. A' control dam was maintained on the same diet without the lead. Following birth and weaning the lead concentration was reduced and an equal number of pups from each litter were sacrificed on days 19, 22, 26, 30, and 35 after birth. The brain lipids were isolated and fatty acid distribution analyzed by gas-liquid chromatography.

Variations in fatty acid distribution between the control and experimental pups were noted for ...


Physical Properties Of Dna From Synchronously Grown Mesophilic And Thermophilic Bacteria, Carol A. Cox Dec 1980

Physical Properties Of Dna From Synchronously Grown Mesophilic And Thermophilic Bacteria, Carol A. Cox

Master's Theses

No abstract provided.


Functions Of Deadenylation Factors In Mrna Decay And Mrna Processing Body Formation, Dinghai Zheng Sep 1980

Functions Of Deadenylation Factors In Mrna Decay And Mrna Processing Body Formation, Dinghai Zheng

UT GSBS Dissertations and Theses (Open Access)

Most newly synthesized messenger RNAs possess a 5’ cap and a 3’ poly(A) tail. The process of poly(A) tail shortening, also termed deadenylation, is important for post-transcriptional gene regulation, because deadenylation not only leads to mRNA translational inhibition but also is the first step of major mRNA degradation. Translationally inhibited mRNAs can be stored and/or degraded in dynamic cytoplasmic foci termed mRNA processing bodies, or P bodies, which are conserved in eukaryotes.

To shed new light on the mechanisms of P body formation and P body functions, I focused on the link between deadenylation factors and P ...


Purification And Properties Of A Hela Cell Enzyme Able To Remove The 5'-Terminal Protein From Poliovirus Rna, Victor Ambros, David Baltimore Jul 1980

Purification And Properties Of A Hela Cell Enzyme Able To Remove The 5'-Terminal Protein From Poliovirus Rna, Victor Ambros, David Baltimore

Victor R. Ambros

Using a rapid phenol extraction assay, an enzyme was purified from uninfected HeLa cells that can cleave the 5'-terminal protein (VPg) from poliovirus RNA. Both cytoplasmic and nuclear extracts had enzymes with similar behavior. A polypeptide of molecular weight 27,000 was the major one present in the purified preparation. Assuming that this protein is the enzyme, a very low turnover number was calculated for it. The purified enzyme would cleave the tyrosine-phosphate bond linking VPg to poliovirus RNA with minimal degradation of the RNA or of VPg. If the RNA was first treated with proteinase K to degrade ...


Encapsidation Of Yeast Killer Double-Stranded Ribonucleic Acids: Dependence Of M On L, Keith A. Bostian, Joyce A. Sturgeon, Donald J. Tipper Jul 1980

Encapsidation Of Yeast Killer Double-Stranded Ribonucleic Acids: Dependence Of M On L, Keith A. Bostian, Joyce A. Sturgeon, Donald J. Tipper

Microbiology and Physiological Systems Publications and Presentations

Virus-like particles containing either L or M double-stranded ribonucleic acid (dsRNA) were isolated from a killer toxin-producing strains of Saccharomyces cerevisiae (K+ R+). At least 95% of M- and 87% of L-dsRNA were recovered in virus-like particle-containing fractions. The major capsid polypeptides (ScV-P1) of both L and M virus-like particles were shown to be identical, and 95% of the cellular ScV-P1 was found in the virus-like particle-containing fractions. Since L-dsRNA encodes ScV-P1, provision of this protein for encapsidation of M-dsRNA defines at least one functional relationship between these dsRNA genomes and associates the L-dsRNA with the killer character. If encapsidation ...


Nutrient Interactions Among Reservoirs On The Colorado River, Larry J. Paulson, John R. Baker Jun 1980

Nutrient Interactions Among Reservoirs On The Colorado River, Larry J. Paulson, John R. Baker

Publications (WR)

Interactions among physical, chemical and biological processes in reservoirs can significantly alter the characteristics of the discharge (Neel 1963, Wright 1967, Hannan 1979) that, in turn, can influence the ecology of the river downstream .(Ward and Stanford 1979). Investigations of the Colorado River, system reveal that reservoir-induced changes in the river can also affect downstream reservoirs. The formation of Lake Powell, in 1963 was accompanied by reductions in suspended sediment and nutrient loading and changes in the seasonal temperature and discharge cycles of the Colorado River. In this paper, we evaluate how these changes have influenced the nutrient and trophic ...


The Effect Of Colchicine On Sexual Reproduction Of Chlamydomonas Moewusii, Anne Leslie Menoff May 1980

The Effect Of Colchicine On Sexual Reproduction Of Chlamydomonas Moewusii, Anne Leslie Menoff

Biology Master’s Theses

The effect of colchicine on the mating reaction in Chlamydomonas moewusii was investigated. Five mM colchicine was found to cause a 96% inhibition of gamete fusion, without disrupting the preceding agglutination reaction or cell motility. Electron microscope examination of colchicine-treated gametes revealed a 98% inhibition of mating structure activation, suggesting that the drug had rendered the gametes incapable of generating and/or responding to the signal for mating structure activation which normally accompanies sexual agglutination. Light microscope analysis revealed that flagella of adhering drug-treated cells entwined loosely so that treated gametes were unable to establish the flagella tip alignment, and ...


The Effect Of Glyoxylate On Photosynthesis And Photorespiration By Isolated Soybean Mesophyll Cells, David J. Oliver May 1980

The Effect Of Glyoxylate On Photosynthesis And Photorespiration By Isolated Soybean Mesophyll Cells, David J. Oliver

David J. Oliver

Incubating isolated soybean leaf mesophyll cells with glyoxylate increased the rates of CO2 fixation by as much as 150%. In order to cause this stimulation, the glyoxylate must be presented to the cells before the NaHCO3. Significant stimulation was observed 15 seconds after beginning the glyoxylate treatment. The glyoxylate-dependent stimulation was increased by high O2 concentrations and decreased by high CO2 concentrations. Glyoxylate treatment resulted in a 71% inhibition in the rate of CO2 incorporation into glycolate and glycine. Glyoxylate may be stimulating net photosynthesis solely by decreasing photorespiration or it may be increasing the amount of CO2 fixed by ...


Studies Of The Reorientational Relaxation Of Pyridine In Water By Depolarized Rayleigh Light Scattering, C. H. Wang, Scott L. Whittenburg, P. A. Lund, D. H. Christensen Apr 1980

Studies Of The Reorientational Relaxation Of Pyridine In Water By Depolarized Rayleigh Light Scattering, C. H. Wang, Scott L. Whittenburg, P. A. Lund, D. H. Christensen

Chemistry and Biochemistry Faculty Publications

The depolarized Rayleigh spectra of aqueous solutions of pyridine have been studied using a high‐finesse Fabry–Perot interferometer as a function of temperature and concentration. The Rayleigh relaxation times are found to have a complex concentration and viscosity dependence. The classical Stokes–Einstein–Debye equation for molecular reorientation breaks down in this system. The Rayleigh relaxation time of pyridine molecules is not determined by the macroscopic shear viscosity of the solution. The specific interaction due to the formation of hydrogen bonds between pyridine and water molecules plays a very important role in affecting the relaxation time. At a fixed ...


Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn Apr 1980

Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn

Rheumatology Publications and Presentations

Nonenzymatic glycosylation of proteins of the erythrocyte membrane was determined by incubating erythrocyte ghosts with [3H]borohydride. The incorporation of tritium into protein provides a reliable assay of ketoamine linkages. The membrane proteins from 18 patients with diabetes incorporated twice as much radioactivity as membrane proteins from normal erythrocytes. After acid hydrolysis, amino acid analysis showed that the majority of radioactivity was localized to glucosyllysine. Autoradiograms showed that all of the major proteins of the erythrocyte membrane, separated by electrophoresis on sodium dodecyl sulfate gels, contained ketoamine linkages. No protein bands in either normal or diabetic erythrocytes showed significant preferential ...


Immunological And Immunohistochemical Methods Used To Study Chromatin Neoantigens Of Novikoff Hepatoma, Steven Binette, Timothy O'Connor Apr 1980

Immunological And Immunohistochemical Methods Used To Study Chromatin Neoantigens Of Novikoff Hepatoma, Steven Binette, Timothy O'Connor

Life and Environmental Sciences Undergraduate Theses

The micro-complement fixation test was used to assay the potency and specificity of rabbit antisera to chromosomal antigens from Novikoff hepatoma and normal rat liver. The complement fixation titration patterns suggest the presence of only a few species of molecules bearing neochromatin antigens. A immunofluorescent technique was adapted to Novikoff hepatoma cells and resulted in the positive staining of Novikoff chromatin and negligible staining in normal rat liver cells.


Cell Wall Synthesis In The Dimorphic Fungus Mucor Rouxii: The Formation Of Uridine Diphosphohexoses, John Witte Apr 1980

Cell Wall Synthesis In The Dimorphic Fungus Mucor Rouxii: The Formation Of Uridine Diphosphohexoses, John Witte

Life and Environmental Sciences Undergraduate Theses

In this paper the properties of the enzymes UDP glucose dehydrogenase and UDP galactose epimerase were characterized. It was shown that UDP glucose dehydrogenase has a considerable lag period, and is activated by the substrate UDP glucose. This activation may be brought about by a disaggregation. Both enzymes were shown to be labile. For accurate kinetic measurements the dehydrogenase must be separated from the epimerase. The UDP galactose epimerase showed no requirements for exogenous NAD+ and demonstrated slight positive cooperativity for UDP galactose. Experiments were carried out in order to determine the specific activity of UDP glucose dehydrogenase during a ...


Adaptative Alteration In Phospholipid Composition Of Plasma Membranes From A Somatic Cell Mutant Defective In The Regulation Of Cholesterol Biosynthesis, Michael Sinensky Jan 1980

Adaptative Alteration In Phospholipid Composition Of Plasma Membranes From A Somatic Cell Mutant Defective In The Regulation Of Cholesterol Biosynthesis, Michael Sinensky

Michael Sinensky

A somatic cell mutant (CR1) of a Chinese hamster ovary cell (CHO-K1) which has previously been shown to be defective in the regulation of cholesterol biosynthesis accumulates more cholesterol than the parental cell line in plasma membranes. Although such an increase in membrane cholesterol should lead to an increase in the order parameter of these membranes, as measured with an electron spin resonance spin probe, the order parameters of mutant and wild-type plasma membranes are identical--apparently because of an adaptive alteration in membrane phospholipid composition. The phospholipid compositions of mutant and wild-type cell plasma membranes are compared and the mutant ...


Studies On The Mechanism Of Reaction Of Papain With N-Acetyl-L-Phenylalanyl Glycinal, A Model For An Elementary Step In Catalysis, Thresiamma Kuppy Jan 1980

Studies On The Mechanism Of Reaction Of Papain With N-Acetyl-L-Phenylalanyl Glycinal, A Model For An Elementary Step In Catalysis, Thresiamma Kuppy

Master's Theses

No abstract provided.


Acetoacetate Decarboxylase Activity Of Fraction V Human Serum Albumin, Robert Richard Rosecrans Jan 1980

Acetoacetate Decarboxylase Activity Of Fraction V Human Serum Albumin, Robert Richard Rosecrans

Dissertations

No abstract provided.


Associations Of N-Acyl Amino Aldehyde Analogs Of Specific Substrates To The Active Site Of Chymotrypsin, William P. Kennedy Jan 1980

Associations Of N-Acyl Amino Aldehyde Analogs Of Specific Substrates To The Active Site Of Chymotrypsin, William P. Kennedy

Dissertations

No abstract provided.


Oxidative Metabolism Of 4-Aminobutyrate By Rat Brain Mitochondria: Inhibition By Branched-Chain Fatty Acid / J. Cunningham, D. D. Clarke, And W.J. Nicklas, J. Cunningham, Donald Dudley Clarke Phd, William J. Nicklas Jan 1980

Oxidative Metabolism Of 4-Aminobutyrate By Rat Brain Mitochondria: Inhibition By Branched-Chain Fatty Acid / J. Cunningham, D. D. Clarke, And W.J. Nicklas, J. Cunningham, Donald Dudley Clarke Phd, William J. Nicklas

Chemistry Faculty Publications

The oxidation of 4-aminobutyric acid (GABA) by nonsynaptosomal mitochondria isolated from rat forebrain and the inhibition of this metabolism by the branched-chain fatty acids 2-methyl-2-ethyl caproate (MEC) and 2,2- dimethyl valerate (DMV) were studied. The rate of GABA oxidation, as measured by 02 uptake, was determined in medium containing either 5 or 100 mM-[K+]. The apparent Km for GABA was 1.16 ± 0.19 mM and the Vmax in state 3 was 23.8 + 5.5 ng-atoms O2 ·min-1.mg protein-1 in 5 mM-[K+]. In a medium with 100 mM-[K+] the apparent K111 was 1.11 ...


Modification Of Aspartate Aminotransferase With Heavy Atoms And With Coenzyme Analogs , Jane Ann Schmidt Jan 1980

Modification Of Aspartate Aminotransferase With Heavy Atoms And With Coenzyme Analogs , Jane Ann Schmidt

Retrospective Theses and Dissertations

Aspartate aminotransferase forms large well-formed crystals on slow concentration by vapor diffusion against solutions of polyethylene glycol. Native enzyme and enzyme blocked at one or both of its surface sulfhydryls with small uncharged substituents were crystallized under the same conditions with methylmercuric chloride, p-chloromercuribenzoate or mercuric acetate in attempts to provide heavy atom derivative crystals. Methylmercury binds to cysteine-191 and cysteine-82 in both native AAT and the enzyme blocked with N-ethylmaleimide. Mercuribenzoate binds to cysteine-82 and cysteine-45 in the native enzyme. Native AAT has been crystallized with 2 equivalents per monomer of methylmercuric chloride or p-chloromercuribenzoate to provide two heavy ...


Immuno- And Bioassayable Extrapituitary Growth Hormone And Thyroid Stimulating Hormone From Discrete Areas Of The Central Nervous System, Sally Ann Hojvat Jan 1980

Immuno- And Bioassayable Extrapituitary Growth Hormone And Thyroid Stimulating Hormone From Discrete Areas Of The Central Nervous System, Sally Ann Hojvat

Dissertations

No abstract provided.


The Role Of Skin Temperature In The Control Of Sweating In Man, Thomas V. Mccaffrey Jan 1980

The Role Of Skin Temperature In The Control Of Sweating In Man, Thomas V. Mccaffrey

Dissertations

No abstract provided.


Chemical Synthesis Of Sucrose Analogues And The Study Of Their Inhibition Of Dextransucrase , John Nicholas Zikopoulos Jan 1980

Chemical Synthesis Of Sucrose Analogues And The Study Of Their Inhibition Of Dextransucrase , John Nicholas Zikopoulos

Retrospective Theses and Dissertations

Several analogues of sucrose were synthesized and tested as inhibitors of dextransucrase. These compounds were as follows: xylsucrose, (alpha)-D-xylopyranosyl fluoride, 6,6'-dideoxy-6,6'-dibromosucrose, 6,6'-dideoxy-6,6'-dichlorosucrose, 6,6'-dideoxy-6,6'-difluorosucrose, 6-deoxy-6-fluorosucrose and 6'-deoxy-6'-fluorosucrose. The last three of which are novel compounds;Xylsucrose was synthesized by the action of levansucrase on a mixture of raffinose and xylose where the raffinose is the fructofuranosyl donor and xylose is the acceptor; (alpha)-D-xylopyranosyl fluoride was synthesized by treating (beta)-D-xylopyranosyl tetraacetate with liquid hydrogen fluoride followed by a deacetylation using sodium methoxide;6,6'-Dideoxy-6 ...


The Purification And Characterization Of Bovine Heart Glycogen Synthase Phosphatase , Barbara Gayle Ruffin Slaughter Jan 1980

The Purification And Characterization Of Bovine Heart Glycogen Synthase Phosphatase , Barbara Gayle Ruffin Slaughter

Retrospective Theses and Dissertations

No abstract provided.


Purification, Properties, And Kinetics Of D-Ribulokinase From Aerobacter Aerogenes , Mark M. Stayton Jan 1980

Purification, Properties, And Kinetics Of D-Ribulokinase From Aerobacter Aerogenes , Mark M. Stayton

Retrospective Theses and Dissertations

No abstract provided.


Aspects Of Glycogen Phosphorylase Catalysis And Regulation , Ronald Joseph Uhing Jan 1980

Aspects Of Glycogen Phosphorylase Catalysis And Regulation , Ronald Joseph Uhing

Retrospective Theses and Dissertations

No abstract provided.


In Vitro Studies Of The Regulation Of Rabbit Phosphoprotein Phosphatase , Sau-Chi Betty Yan Jan 1980

In Vitro Studies Of The Regulation Of Rabbit Phosphoprotein Phosphatase , Sau-Chi Betty Yan

Retrospective Theses and Dissertations

No abstract provided.