Life Sciences Commons^™

Research Note: Getting Graphic: Computer Graphics In Biochemistry, Wilmon B. Chipman

Bridgewater Review

No abstract provided.

Modification Of Chromium(Vi)-Induced Dna Damage By Glutathione And Cytochromes P-450 In Chicken Embryo Hepatocytes., Doreen Y. Cupo, Karen E. Wetterhahn

Dartmouth Scholarship

The role of glutathione and cytochrome P-450 in the production of DNA damage by chromium(VI) was examined in chicken embryo hepatocytes by the alkaline elution technique. Cellular levels of glutathione and cytochrome P-450 were altered by treating the hepatocytes with N-acetyl-L-cysteine, buthionine sulfoximine, isopentanol, or beta-naphthoflavone. A dramatic increase in chromium(VI)-induced DNA strand breaks was observed after increasing glutathione levels in the cells. Chromium(VI)-induced DNA strand breaks were even more numerous when the level of cytochrome P-450 was also increased. Upon depletion of glutathione levels and induction of cytochrome P-450 or cytochrome P-448, little or no DNA strand breaks or …

Determination Of Total And Unfilterable Plasma Aluminum In Uremic Patients, Theodore R. Delbridge

Chemistry & Biochemistry Theses & Dissertations

Aluminum accumulation in the soft tissues and bone of end stage renal failure patients has been described in the literature. In addition to aluminum normally encountered through ubiquitous sources, these patients are subject to exposures through the dialysate used for hemodialysis and through aluminum-containing phosphate binders. These increased exposures, associated with a decreased ability to excrete aluminum through the kidneys, lead to aluminum accumulation which may result in the onset of an encephalopathy syndrome and/or osteomalacic osteodystrophy. These complications may be very devastating.

Blood serum or plasma aluminum levels do not reflect the total body burden of aluminum. However, they …

Isolation And Characterization Of A Novel Motility Mutant In Salmonella Typhimurium, David Matthew Chacko

Loma Linda University Electronic Theses, Dissertations & Projects

A new mutant, BT40, isolated from mutagenized cultures of S. typhimurium was deficient in chemotaxis (Che^- phenotype) in tryptone semisoft agar, but had random motility with a tumbling frequency (37%) similar to that of the parental strain, ST23 (39%). In spatial assays accumulation of BT40 cells in capillary tubes containing attractants was decreased by 33%-59% compared to ST23, but BT40 had a normal response to attractants in temporal assays. The methylation level of the chemotactic proteins was decreased in BT40. At room temperature, the mean swimming speed was 11 μm/s for BT40 and 20 μm/s for ST23; more BT40 …

Choline Inhibition Of Prothrombinase, Richard D. Leach

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to characterize the inhibitory effects of choline on the terminal enzymatic complex of the blood coagulation cascade. Reports in the literature have indicated that choline lengthens whole plasma clotting time with a likely site of inhibition being the step that converts prothrombin (II) to thrombin (IIa).

In order to quantitate the effects of choline on prothrombinase activity, bovine factor V and human factor II were isolated in this laboratory by established methods, and other prothrombinase components were obtained from commercial sources. The activity of venom-activated bovine factor Xa was assayed in the presence of …

The Relationship Of Vitamins B-6 And B-12 To Plasma Homocysteine Levels In Men At Low- And High-Risk For Coronary Heart Disease, Marlene E. Swift

Loma Linda University Electronic Theses, Dissertations & Projects

There is evidence that homocysteine may be a factor in increasing the risk of coronary heart disease (CHD). To explore this relationship further, we assessed the interrelation of dietary vitamins B-6, B-12 and folate, and plasma pyridoxal-5'-phosphate and vitamin B-12 with plasma free and protein-bound homocysteine levels. Fasting blood and three-day dietary records were obtained from nine men low-risk (LR) and five at high-risk (HR) for CHD. The HR mean systolic blood pressure, total cholesterol (TC), and TC/cholesterol ratios were significantly higher than LR levels. Groups were comparable by age, weight, height, skinfolds, exercise, and smoking history. No significant difference …

Acetylcholinesterase In The Neonatal Rat Brain: The Effects Of Prenatal Ethanol Exposure, Linda M. Boland

Biological Sciences Theses & Dissertations

Acetylcholinesterase (AChE) activity in the neonatal rat brain was determined by histochemical localization and quantitative biochemical analysis. AChE-positive perikarya were concentrated in the neostriatum, globus pallidus, medial habenular nucleus, amygdaloid complex, various hypothalamic nuclei, gigantocellular and paragigantocellular reticular nuclei, raphe nuclei, locus coeruleus, and motor nuclei of cranial nerves III-VII and IX-XII. Some areas stained differently or not at all when compared with the adult rat brain. The effects of prenatal ethanol exposure on regional AChE activity were assessed by comparing enzyme levels in offspring exposed via maternal consumption of a liquid diet containing 35 percent ethanol derived calories. This …

A Biochemical And Genetic Analysis Of The American Shad Alosa Sapidissima Migrating Into The Chesapeake Bay, Edward Norbert Sismour

Biological Sciences Theses & Dissertations

Seven enzymes extracted from heart and liver tissues of American shad Alosa sapidissima captured during migrations into the Chesapeake Bay and Nansemond River were electrophoretically surveyed. Malate dehydrogenase and nonspecific esterase displayed polymorphic loci. The esterase polymorphism was used as a biochemical genetic marker to analyze the shad migration through the southern Chesapeake Bay. The genetic composition of the shad migration changed significantly over time indicating that this migration is probably composed of multiple, genetically divergent spawning populations. Results of this study are subject to differing interpretations. Observed temporal heterogeneity may result from separation of northern and James River stocks …

Human Lung Tryptase Purification And Characterization, Timothy J. Smith

Electronic Theses and Dissertations

Human lung tryptase (HLT), a mast cell derived trypsin-like enzyme, was isolated from whole human lung tissue obtained at autopsy. Increased yields from this purification process allowed extensive characterization of the enzyme. One of the critical steps in the purification scheme was the use of a linear heparin gradient to elute active material from cellulose phosphate. Gel filtration studies in 1.0 M NaCl yielded an apparent M(,r) of 135,000, and subsequent electrophoresis on sodium dodecyl sulfate-polyacrylamide gels demonstrated the presence of two active species with apparent M(,r) = 30,900 and 31,600. Enzymatic activity was sensitive to NaCl concentrations above 0.05 …

Inhibition Of Glycine Oxidation By Carboxymethoxylamine, Methoxylamine, And Acethydrazide, G. Sarojini, David J. Oliver

David J. Oliver

Carboxymethoxylamine (amino-oxyacetate), methoxylamine, and acethydrazide are shown to be effective, although not completely specific, inhibitors of glycine oxidation by the isolated glycine decarboxylase multienzyme complex, mitochondria, protoplasts, and leaf discs from peas. The inhibition probably results from a reaction between these compounds and the pyridoxal 5-phosphate cofactor of the enzyme.

Lectins, El-Nasir Lalani, M Wells

Department of Pathology and Laboratory Medicine

No abstract provided.

Transition-State Analog Affinity Purification Of Proteases, Arunbhai Patel

Dissertations

No abstract provided.

Cloning And Characterization Of A Gene (Fadr) Involved In Regulation Of Fatty Acid Metabolism In Escherichia Coli, Concetta C. Dirusso, William D. Nunn

Department of Biochemistry: Faculty Publications

The regulatory gene fadR has been previously characterized by classical genetic means as a diffusible protein which exerts negative control over fatty acid degradation and acetate metabolism. fadR has also been implicated in the regulation of unsaturated fatty acid biosynthesis. To facilitate the identification of the product of the fadR gene and to study the mechanism by which this multifunctional regulatory gene exerts its control, we cloned a segment of DNA containing the fadR gene in the phage vector λL47. Subsequent subcloning of a segment of the chromosomal DNA from the λfadR⁺ phage into various plasmid vectors resulted in …

Proliferation Of Schwann Cells Induced By Axolemmal And Myelin Membranes, Michael Paul Dinneen

Theses and Dissertations

Purified Schwann cells were cultured from neonatal rat sciatic nerve using a modification of the method of Brockes (Brockes, J.P. et al, Brain Res. 165(1979) 105-118). Schwann cells and contaminating fibroblasts were unambiguously identified using fluorescent antibodies to 2'3' cyclic nucleotide 3'-phosphodiesterase and the thy 1.1 antigen respectively. The Schwann cells were quiescent unless challenged with mitogens, They proliferated rapidly in response to the soluable mitogen, cholera toxin, or to membrane fractions from rat CNS or PNS, prepared by the method of DeVries (DeVries, G.H., J Neurochem, 40 (1983) 1709-1717). Mitogenic activity was present in both axolemmal and myelin enriched …

Acetylation-Deacetylation Of Synaptosomal Proteins: Effect Of Na+ / S. Berl, A. Colon And D. D. Clarke. Mt. Sinai School Of Medicine, New York, N.Y. 10029, Soll Berl, Arlene D. Colon, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Synaptosomes (S) when incubated with 3H-acetate (HA), are rapidly labeled. The perchloric acid (PCA) precipitable proteins contain most of the radioactivity probably as the acetyl moiety, which is released in a volatile form after acid or base hydrolysis (Berl et al., - J. Neurochem. 40:176, 1983). Much of the radioactivity was chased by addition of unlabeled acetate suggesting that the acetylation was reversible. Labeling was also decreased in the presence of veratridine/veratrine (V, 100uPt!) and this effect was prevented by tetrodotoxin (2uM). When Na was omitted from the incubation medium, the incorporation of (HA) was increased; however, the effect of …

Concanavalin A-Binding Enzymes Of Crotalus Scutulatus Scutulatus Venom, Michael W. Hinson, C. K. Childs, Bob D. Johnson, Dewey H. Sifford

Journal of the Arkansas Academy of Science

Crotalus scutulatus scutulatus crude venom was separated into two fractions by Concanavalin A Sepharose 4B affinity chromatography. The proteins binding to Con A exhibited phosphomonoesterase (orthophosphoric monoester phosphohydrolase EC 3.1.3.2), phosphodiesterase, 5'-nucleotidase (5'-ribonucleotide phosphohydrolase EC 3.1.3.5), phospholipase A(phosphatidate 2-acylhydrolase EC 3.1.1 .4), hyaluronidase (hyaluronate glycanohydrolase EC 3.2.1 d), N-benzoyl-L-arginine ethyl esterase, p-toluenesulfonyl-L-arginine methyl esterase, L-amino acid oxidase (L-amino acid: 02 oxidoreductase [deaminating] EC 1.4.3.2), and caseinolytic activities. Thrombin-like and NAD nucleosidase (5'-ribonucleotide phosphohydrolase EC 3.1.3.5) activities were not observed. The crude venom and the fraction containing the glycoproteins which bound to Con A were fractionated by DEAE Sephadex A-50 ion …

Response Of A Nitrifying Biofilm To Copper, Denise Moldroski Mott

Masters Theses

In pure cultures of Nitrosomonas, copper is known to cause a stimulation of nitrification at low levels (≤ 0.03 mg Cu⁺²/1) and an inhibition affect at higher levels (≥ 0.05 mg Cu⁺²/1). Nitrifying activated sludges are much more tolerant of copper showing only 75% inhibition at 150mg Cu⁺²/1. The purpose of this paper was to determine the copper sensitivity of a nitrifying biofilm grown in a continuous flow trickling filter system.

A continuous flow trickling filter system was built using limestone chips for the biofilm substrate. The biofilm was established from secondary effluent. …

Demonstration Of A Heat-Stable Cyclic Gmp Phosphodiesterase In The Medium Of Physarum Flavicomum, Thomas J. Lynch, Mark S. Ross

Journal of the Arkansas Academy of Science

No abstract provided.

Effects Of Growth Temperatures On The Fatty Acid Composition Of Isolated Chloroplasts From Two Species Differing In Heat Sensitivity, Roy Z. Gehring, Glenn W. Todd

Journal of the Arkansas Academy of Science

Lipid analyses of chloroplasts isolated from wheat (Triticum aestivum L. cv. Arthur) and milo (Sorghum bicolor cv. Funk's hybrid 522) suggest no major heat effect on lipid class distribution. Assuming milo is more heat tolerant than wheat and that increased saturated/unsaturated fatty acid values increase thermal stability, changes in sulfoquinovosyldiglyceride (SL) appear to be more important than phosphatidylglycerol (PG) in conferring thermal stability to isolated chloroplasts.

Methemoglobin Reduction In The Presence Of Various Concentrations Of Oxyhemoglobin, Ali Mansouri

Journal of the Arkansas Academy of Science

Methemoglobin reduction in human red blood cell is governed by many factors, one of which is the concentration of oxyhemoglobin. Experiments were conducted to determine the inhibition of methemoglobin reduction by oxyhemoglobin under concentrations approaching those in the red cell. Hemoglobin, methemoglobin reductase and cytochrome b₅ were prepared by routine protein purification methods. Methemoglobin reduction was carried out at 37° C in spectrophotometer. It is shown that methemoglobin concentration variation (at least when it is above 1 mM) does not change the reduction rate. Whereas, the ratio of methemoglobin to oxyhemoglobin determines the rate of methemoglobin reduction when all other …

Aspects Of Mitochondrial Oxidative Metabolism, Leslie Kushner

Dissertations, Theses, and Capstone Projects

The effects of metabolic intermediates and coenzymes on the activities of fatty acyl-CoA synthetase and carnitine palmitoyltransferase (CPT) in rat heart mitochondria were studied. ADP and palmitoyl-l-carnitine were weak inhibitors of fatty acyl-CoA synthetase. CPT A was inhibited 59.3% by 100 (mu)M succinyl-CoA. However, succinate thiokinase activity in rat heart cytosol was too low to maintain a succinyl-CoA concentration sufficient to affect the activity of CPT A. There was no indication that fatty acid oxidation in rat heart mitochondria is controlled via the regulation of either CPT A or fatty acyl-CoA synthetase.

The dependence of the oxidation of unsaturated fatty …

Collagen Fibril Formation Sds.Pdf, George W. Dombi, Brian H. Halsall

George Dombi

No abstract provided.