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Full-Text Articles in Life Sciences
Proteomics Of Carbon Fixation Energy Sources In Halothiobacillus Neapolitanus, Jonathan Hunter, Maria Marasco, Ilerioluwa Sowande, Newton P. Hilliard Jr.
Proteomics Of Carbon Fixation Energy Sources In Halothiobacillus Neapolitanus, Jonathan Hunter, Maria Marasco, Ilerioluwa Sowande, Newton P. Hilliard Jr.
Journal of the Arkansas Academy of Science
Through the use of proteomics, it was uncovered that the autotrophic, aerobic purple sulfur bacterium Halothiobacillus neapolitanus displays changes in cellular levels of portions of its carbon dioxide uptake and fixation mechanisms upon switch from bicarbonate to CO2(g) as carbon source. This includes an increase in level of a heterodimeric bicarbonate transporter along with a potential switch between form I and form II of RubisCO. Additional changes are seen in several sulfur oxidation pathways, which may indicate a link between sulfur oxidation pathways as an energy source and carbon uptake/fixation mechanisms.
Synthesis, Characterization, And Properties Of Mononuclear And Dinuclear Ruthenium(Ii) Complexes Containing Phenanthroline And Chlorophenanthroline, Anwar A. Bhuiyan, X. Du
Synthesis, Characterization, And Properties Of Mononuclear And Dinuclear Ruthenium(Ii) Complexes Containing Phenanthroline And Chlorophenanthroline, Anwar A. Bhuiyan, X. Du
Journal of the Arkansas Academy of Science
The study of photophysical and photochemical properties of ruthenium complexes is of great interest for fundamental practical reasons. Ruthenium complexes have been investigated for use in artificial photosynthesis. This paper deals with the synthesis and spectroscopic investigation of custom-designed ruthenium complexes containing phenanthroline and chloro-phenanthroline ligands. These complexes maybe useful for biological electron-transfer studies. The heteroleptic ruthenium monomer complex Ru(phen)2(Cl-phen) (where phen = 1,10-phenanthroline and Cl-phen=5-chloro-1,10-phenanthroline) was prepared in a two-step procedure previously developed in our laboratory. This monomer complex was used to prepare the ruthenium homometallic dimer complex, (phen)2Ru(phen-phen)Ru(phen)2, by utilizing the Ni-catalyzed coupling reaction. Both complexes were purified …
Valence-Length Correlations For Chemical Bonds From Atomic Orbital Exponents, F. D. Hardcastle
Valence-Length Correlations For Chemical Bonds From Atomic Orbital Exponents, F. D. Hardcastle
Journal of the Arkansas Academy of Science
Pauling’s empirical bond valence-length correlation has proven valuable because it offers a quick and convenient way of checking and evaluating molecular structures and determining oxidation states from measured bond lengths. In this study, a simplified quantum-mechanical approach was used to derive Pauling’s empirical bond valence-length relationship by considering overlap of hydrogen-like orbitals. An expression for the b “empirical” fitting parameter was derived in terms of atomic-orbital exponents. A new set of orbital exponents is presented using published atomic/covalent radii and a continuous function for the effective principal quantum. The b parameters calculated from the orbital exponents are consistent with bond …
Rec12 (Spo11) Recominase Of Fission Yeast Promotes A Backup, Distributive Pathway For Chromosome Segregation In Meiosis I, Wallace D. Sharif, Mari K. Davidson, Wayne P. Wahls
Rec12 (Spo11) Recominase Of Fission Yeast Promotes A Backup, Distributive Pathway For Chromosome Segregation In Meiosis I, Wallace D. Sharif, Mari K. Davidson, Wayne P. Wahls
Journal of the Arkansas Academy of Science
We studied the relationship between recombination and segregation in the fission yeast Schizosaccharomyces pombe. In meiosis, chromosomes undergo two rounds of segregation to produce haploid meiotic products. Crossover meiotic ecombination (chiasmata) promotes chromosome segregation during meiosis I; achiasmatic chromosomes often suffer on disjunction in meiosis I. Recl2 protein is a topoisomerase IIortholog that introduces double-strand DNA breaks that nitiate recombination. The red2 null (deletion) and active site (Y98F) mutants lack recombination and crossovers, and onsequently suffer meiosis I nondisjunction. However, null mutants chromosomes segregate to opposite poles more frequently than predicted. Thus, fission yeast has a backup, "distributive segregation" pathway …
Molecular Orbital Studies Of Nitrosyl Metalloporphyrin Complexes, John P. Graham, Genevive Brown
Molecular Orbital Studies Of Nitrosyl Metalloporphyrin Complexes, John P. Graham, Genevive Brown
Journal of the Arkansas Academy of Science
Molecular orbital calculations are applied to the study of the structure and bonding of nitrosyl metalloporphyrin complexes. The Fenske-Hall approximate molecular orbital method and the Amsterdam Density Functional (ADF) method are used. The calculations provide qualitative and quantitative explanations for the observed structural differences between the nitrosyl porphyrin complexes ofiron, manganese, and cobalt. It is proposed that the energy of the highest occupied molecular orbital (HOMO) of these complexes is primarily responsible for the observed structural differences. The interaction between the nitrosyl ligand and metal dz2 orbital results in an antibonding orbital that is occupied in the complexes of Fe …
Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt
Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt
Journal of the Arkansas Academy of Science
Phytoestrogens are biochemicals synthesized in plants which mimic steroidal estrogen activity in mammals. Analysis of these compounds in the legumes which produce them and in body fluids is important to the study of their physiological effects. High pressure liquid chromatography (HPLC) has been found to be an efficient and sensitive method of identification and quantitation of isoflavonoids, one class of phytoestrogen. Here we report the separation of three isoflavonoids, biochanin A, genistein and daidzein using an HPLC system with a Cg reverse phase column and a linear gradient mobile phase containing acetonitrile and acetic acid/water (10/90, v/v) over 60 minutes. …
Thermal Decomposition Studies Of Selected Transition Metal Polysulfide Complexes. Ii. Effect Of Atmosphere On Decomposition, Benjamin Rougeau, Mark Draganjac
Thermal Decomposition Studies Of Selected Transition Metal Polysulfide Complexes. Ii. Effect Of Atmosphere On Decomposition, Benjamin Rougeau, Mark Draganjac
Journal of the Arkansas Academy of Science
Initial studies involved the thermal decomposition profile of five polysulfide complexes in air up to 550 °C. Since our first report to the Academy in 1990, we have obtained the capability to run samples up to 1500°C under various gases. Thermal Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA)of a series of transition metal polysulfide complexes are presented. Compounds analyzed included Cp2TiS5 ,MoS9 2",MoOS8 2", Zn(S x ) 2", Cd(S x ) 2-, Fe2S122 - and NiS82.
Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan
Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan
Journal of the Arkansas Academy of Science
No abstract provided.
Mermithid Nematodes: Sem Observations Comparing Hexamethyldisilazane And Critical Point Drying Methods, William R. Bowen, Christopher C. Hemann, Arthur A. Johnson, Barry H. Good
Mermithid Nematodes: Sem Observations Comparing Hexamethyldisilazane And Critical Point Drying Methods, William R. Bowen, Christopher C. Hemann, Arthur A. Johnson, Barry H. Good
Journal of the Arkansas Academy of Science
Morphological features of mermithid nematodes (Mermithidae) were studied with scanning electron microscopy, using hexamethyldisilazane-air drying in comparison with critical point drying via liquid carbon dioxide. Although general morphologic preservation of both HMDS-dried and CP-dried specimens was similar, structural features of the complex cuticle and internal organization were more easily resolved at higher magnifications in the HMDS-dried nematodes. These features include the superficial cuticular annulations, the fibrillar inner cuticle and peg-like microtrabeculae. The previously undescribed microtrabeculae are of special interest since they may facilitate an interaction of the mermithid (and perhaps nameatodes in general) musculature with its body wall that, at …
Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad
Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad
Journal of the Arkansas Academy of Science
The compact ordered conformations of the molecule N-Acteyl-L-Prolyl-D-Alanyl-Methylamide have been studied by semiempirical energy calculations in vacuum and circular dichroism (CD) in solution. The presence of ordered structure has been observed in hydrogen bond promoting solvents like trifluoroethanol by CD studies. In hydrogen bond breaking solvents, like trifluoroacetic acid (TFA), significant fraction of the ordered conformers probably assume extended conformation without intramolecular hydrogen bonds and perhaps are in equilibrium with the fraction of compact ordered structures. The trend observed in going from nonpolar to polar solvent is also compatible with the previous NMR studies in solution. The semiempirical energy calculations …
Spectrophotomatic Assay For The Enzyme Catalyzed Reaction Of 4-Nitroquinoline 1-Oxide With Glutathione, J. Steven Stanley, Ann M. Benson
Spectrophotomatic Assay For The Enzyme Catalyzed Reaction Of 4-Nitroquinoline 1-Oxide With Glutathione, J. Steven Stanley, Ann M. Benson
Journal of the Arkansas Academy of Science
4-Nitroquinoline 1-oxide (4NQO(is a toxic and carcinogenic compound that has been reported to be subject to conjugation with glutathione (GSH). This reaction may proceed non-enzymatically or be catalyzed by GSH transferases. The non-enzymatic rate for this reaction has been reported to be very high. The purposes of this investigation were to develop a spectrophotometric assay for the reaction of4NQO with GSH and to determine whether the rate for the enzyme catalyzed reaction was significant relative to the non-enzymatic reaction. The absorbance spectrum of 4NQO in phosphate buffer exhibited a maximum at 365 nm. Reaction of 4NQO with GSH was accompanied …
Concanavalin A-Binding Enzymes Of Crotalus Scutulatus Scutulatus Venom, Michael W. Hinson, C. K. Childs, Bob D. Johnson, Dewey H. Sifford
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 …
Demonstration Of A Heat-Stable Cyclic Gmp Phosphodiesterase In The Medium Of Physarum Flavicomum, Thomas J. Lynch, Mark S. Ross
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
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
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 …
Neutral Sugars In Selected Pit Viper, Elapid, Lizard And Scorpion Venoms, Ahmed El-Sherif, Paul D. Gwinup, Bob D. Johnson, Dewey H. Sifford
Neutral Sugars In Selected Pit Viper, Elapid, Lizard And Scorpion Venoms, Ahmed El-Sherif, Paul D. Gwinup, Bob D. Johnson, Dewey H. Sifford
Journal of the Arkansas Academy of Science
No abstract provided.
Dietary Fat-Carbohydrate Combinations: Their Effects On Lipid Metabolism In Estrogen-Treated Rats, Beverly A. Clevidence
Dietary Fat-Carbohydrate Combinations: Their Effects On Lipid Metabolism In Estrogen-Treated Rats, Beverly A. Clevidence
Journal of the Arkansas Academy of Science
Female rats 4 weeks old were fed diets including beef tallow or safflower oil in combination with sucrose or rice starch. At 8 weeks of age, half the rats were orally administered 2 of estrogen (mestranol) in 5 μl of safflower oil and half were fed the vehicle only. After 10 to 14 days of estrogen treatment, rats were fasted and exsanguinated. Alterations were found in weight gain, liver weights, and levels of various lipids in plasma and liver. Most lipid levels were influenced by an interaction of mestranol with one of the dietary factors. No changes were observed in …
Effect Of Estrogen And/Or Supplemental Substrates On Uterine Utilization Of Pyruvate For Lipid Synthesis, Julie W. Harris
Effect Of Estrogen And/Or Supplemental Substrates On Uterine Utilization Of Pyruvate For Lipid Synthesis, Julie W. Harris
Journal of the Arkansas Academy of Science
Precursor incorporation into uterine lipids was examined in vitro after estradiol-17ß administration in immature female rats. The effect of adding supplemental substrates, glucose or gluconate, to the incubation medium on the labeling pattern of pyruvate-3-¹⁴C into uterine lipids was studied. Presence of supplemental substrate in the medium enhanced the incorporation of pyruvate into uterine lipids after two hours of in vivo estrogen treatment. It is suggested that estrogen's acceleration of pyruvate incorporation into lipid may be due to a concomitant effect on glucose metabolism.
Enzymes In Heloderma Horridum Venom, S. A. Murphy, Bob D. Johnson, D. H. Sifford
Enzymes In Heloderma Horridum Venom, S. A. Murphy, Bob D. Johnson, D. H. Sifford
Journal of the Arkansas Academy of Science
A mixture of venom and saliva from the lizard Heloderma horridum was analyzed for esterase, phosphomonoesterase, phosphodiesterase, 5'nucleotidase, and protease activities. Hydrolysis of N-benzoyl-L-arginine ethyl ester occurred at a pH optimum between pH 8.6 and 9.1 with a maximum activity of 452 units per mg per min. Hydrolysis of ptoluenesulfonyl-L-arginine methyl ester occurred at a pH optimum between pH 8.1 and 8.5 with a maximum of only 36 units per mg per min. One mg of the venom mixture liberated 9.3 μM of p nitrophenol from p-nitrophenyl phosphate per minute at an optimum pH between 8.2 and 8.3. Over a …
Influence Of Dietary Fats And Carbohydrates On Lipid Metabolism In Male And Female Rats, Marjorie Ellen Fitch
Influence Of Dietary Fats And Carbohydrates On Lipid Metabolism In Male And Female Rats, Marjorie Ellen Fitch
Journal of the Arkansas Academy of Science
Effects of dietary fats and carbohydrates on lipid metabolism in rats were studied. Male and female 4-week-old rats were divided into 8 groups and fed 4 fat-carbohydrate combinations (beef tallow or safflower oil, each with either sucrose or rice starch). After 4 weeks, animals were killed by exsanguination through the abdominal aorta and livers were removed. Plasma and liver cholesterol and phospholipids were determined qualitatively and quantitatively. Liver moisture, protein, and lipid and the fatty acid composition of the total liver lipid were determined quantitatively. Variations in growth, food efficiency, and lipid metabolism, particularly as manifested by the fatty acid …
Metabolic Responses Of White Rats To Glucose Or Fructose Fed With Two Safflower Oils Containing Different Proportions Of Fatty Acid, Paula Lynn Yates
Metabolic Responses Of White Rats To Glucose Or Fructose Fed With Two Safflower Oils Containing Different Proportions Of Fatty Acid, Paula Lynn Yates
Journal of the Arkansas Academy of Science
No abstract provided.
Metabolic Changes Induced In Rats By Feeding Different Levels Of Galactose With Two Levels Of Corn Oil, Carolyn Qualls Sharp
Metabolic Changes Induced In Rats By Feeding Different Levels Of Galactose With Two Levels Of Corn Oil, Carolyn Qualls Sharp
Journal of the Arkansas Academy of Science
No abstract provided.
Interrelationships Of Certain Metabolic Responses To Threonine Deficiency And To Various Dietary Carbohydrates In The White Rat, Elizabeth Bright
Interrelationships Of Certain Metabolic Responses To Threonine Deficiency And To Various Dietary Carbohydrates In The White Rat, Elizabeth Bright
Journal of the Arkansas Academy of Science
No abstract provided.
Effects Of Saturated And Unsaturated Long Chain Fatty Acids On Various Components Of Lipid And Carbohydrate Metabolism, Joyce T. Burgess
Effects Of Saturated And Unsaturated Long Chain Fatty Acids On Various Components Of Lipid And Carbohydrate Metabolism, Joyce T. Burgess
Journal of the Arkansas Academy of Science
No abstract provided.
Effect Of Dietary Galactose Vs. Glucose With Corn Oil And With Hydrogenated Coconut Oil On Various Metabolic Functions In Rats, Mabel R. Coleman, Catherine Carroll
Effect Of Dietary Galactose Vs. Glucose With Corn Oil And With Hydrogenated Coconut Oil On Various Metabolic Functions In Rats, Mabel R. Coleman, Catherine Carroll
Journal of the Arkansas Academy of Science
No abstract provided.