171,768 research outputs found

    Sheep liver cytosolic aldehyde dehydrogenase : a fresh perspective : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry at Massey University, New Zealand

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    The pre-steady-state mechanism of aldehyde dehydrogenase has been further investigated using synthesised deuterated 4-trans-(N,N-dimethylamino) cinnamaldehyde as a substrate. Reporter groups of the active site of ALDH have indicated the presence of a divalent or trivalent metal electrophile, shown in chapter 3 as being either Fe (II) or Fe (III) . Studies of the spectral properties of NADH bound to aldehyde dehydrogenase have revealed the presence of at least two spectrally different enzyme-NADH species. The consequences of this information are important in interpretation of the kinetic data and understanding apparently contradictory experimental results from different research workers. The steady-state kinetics of ALDH have been further investigated. A sensitive substrate for use in enzyme immunoassays has been designed and synthesised. The preliminary kinetic behaviour observed using this substrate has been studied with three enzymes. Aldehyde dehydrogenase has been used as a model system for studying the effects of electromagnetic radiation on biological systems

    Azine polymers and process for preparing the same Patent

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    Synthesis of azine polymers for heat shields by azine-aromatic aldehyde reactio

    Polyvinyl alcohol cross-linked with two aldehydes

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    A film forming polyvinyl alcohol resin is admixed, in aqueous solution, with a dialdehyde crosslinking agent which is capable of crosslinking the polyvinyl alcohol resin and a water soluble acid aldehyde containing a reactive aldehyde group capable of reacting with hydroxyl groups in the polyvinyl alcohol resin and an ionizable acid hydrogen atom. The dialdehyde is present in an amount sufficient to react with from 1 to 20% by weight of the theoretical amount required to react with all of the hydroxyl groups of the polyvinyl alcohol. The amount of acid aldehyde is from 1 to 50% by weight, same basis, and is sufficient to reduce the pH of the aqueous admixture to 5 or less. The admixture is then formed into a desired physical shape, such as by casting a sheet or film, and the shaped material is then heated to simultaneously dry and crosslink the article

    Aldehyde Dehidrogenase Level and Fatty Acid Ethyl Ester as Biochemical Markers Persist Longer Than Ethanol in Wistar Rats After Chronic Alcohol Consumption

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    Alcohol consumption in human has increased from year to year in Indonesia and more recently, anincreasing number of cases of alcohol intoxication, alcoholic liver disease, and death were observed.The purpose of this experimental study was to examine the significance of two known biochemicalmarkers of alcohol given by mouth in the Wistar rats. The study design used was the “Truerandomized experimental post test only control group design". The rats were randomly distributedaccording to the experimental design and were treated daily for six weeks (chronic intake) with 5%and 20% alcohol. This study used 15 rats with 5 rats for treatment group treated with 5% alcohol, 5rats for treatment group treated with 20% alcohol, and 5 rats as control group treated with distilledwater. The biochemical markers were aldehyde dehydrogenase (ALDH) and Fatty Acid Ethyl Esters(FAEE). ALDH and FAEE were two biochemical markers of ethanol which are sensitive and specificfor alcohol consumption. The study was conducted in two phases. Initially, rats were treated orallyeveryday for six weeks with 5% and 20% alcohol, and then the blood level of ethanol, ALDH andFAEE were measured. Blood samples were collected at 6 and 24 hours after the last oral intake ofchronic alcohol administration. Qualitative analysis was carried out to detect the presence of ethanol,ALDH, and FAEE in the treatment groups and quantitative analysis to determine their levels in theblood of Wistar rats. Statistical analysis of ALDH was done by using parametric test and the presenceof FAEE persisting longer than ethanol by non-parametric test. The results showed that ALDHpersisted and increased significantly following chronic consumption of alcohol in the rats. Similarly,FAEEs persisted longer than ethanol after alcohol intake. After six hours, the ALDH level increasedby 108.14% in the rat treated chronically with 5% alcohol and by 85.07% in rat treated with 20%alcohol. After 24 hours, FAEE also persisted longer in the blood than ethanol following treatmentwith alcohol 5%. ALDH levels increased by 83.11% after chronic treatment with 5% alcohol and by112.05% in the rats treated with 20% alcohol. In the blood collected 24 hours after the last treatmentwith 5% alcohol, ALDH increased by 95.11% and by 86.79% in the rats treated with 20% alcohol.FAEE persisted longer than ethanol in the blood following administration of 5 % and 20% alcoholboth at 24 hours following chronic treatment. The longer persisting ALDH and FAEE were new andgood biochemical blood markers for chronic alcohol consumption in the Wistar rats

    Immobilisation of enzymes to Perloza cellulose resin : this thesis was presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University /

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    The studies reported in this thesis describe the use of Perloza™ beaded cellulose resin as a solid support for enzyme immobilisation via covalent binding. The aim of the project was to extend the uses for Perloza™ and to compare the use of well known solid support activation chemistries with a recently developed one for Perloza™. Preparations such as these have potential industrial uses. Three attachment chemistries were studied. The first activation employed 1,1-carbodiimidazole (CDI) then direct attachment of enzyme. The second again used CDI activation followed by attachment of a 6-aminocaproic acid spacer arm and then the enzyme. The final method used was attachment of a diol and subsequent oxidation to an aldehyde. The diol/aldehyde method had the advantage over the CDI methods of being based on aqueous chemistries. The two CDI based methods require extensive use of dry organic solvents. The enzymes investigated in this study were trypsin, chymotrypsin. α-amylase, horseradish peroxidase (HRPO) and alcohol dehydrogenase (ADH). Trypsin was immobilised successtully by all three chemistries. All preparations retained significant activity after immobilisation at room temperature as judged by the chromogenic substrate specific for trypsin N-α-benzoyl-DL-arginine-p-nitroanilide.HC1 (BAPNA). Measurable activity was retained in different studies from between 2 to 7 days at 60°C. The activity of immobilised trypsin with a synthetic peptide substrate was comparable to the activity of free trypsin with the same substrate. Chymotrypsin was also successfully immobilised using all three chemistries. Each preparation showed significant retention of activity after immobilisation as judged by the chromogentic substrate N-glutaryl-L.-phenylalanine-p-nitroanilide (GAPNA). Stabilisation to heating at 60°C was less successful than with trypsin but significant activity was still retained for between 3 and 6 hours. The activity of immobilised preparations with a peptide substrate was comparable to free chymotrypsin. α-Amylase, horseradish peroxidase and alcohol dehydrogenase were studied less extensively than trypsin and chymotrypsin. Nevertheless all three enzymes were successfully immobilised onto Perloza™-CDI-ACA and Perloza™-Diol/Aldehyde. Difficulty was encountered in achieving significant levels of any enzyme immobilisation to Perloza™-CDI for all three enzymes. Subsequent activity assays showed HRPO and α-amylase retained significant activity on all three resin preparations. ADH showed no measurable activity on Perloza™-CDI and very little activity on Perloza™- CDI-ACA and Perloza™-Diol/Aldehyde. Investigations have shown that enzymes can be immobilised on Perloza™ with retention of significant amounts of normal activity at room temperature and improved stability compared with free enzyme at high temperature. Comparisons of the CDI activations with the diol/aldeyde chemistry showed better performance by the latter in trypsin immobilisation and similar performance for chymotrypsin immobilisation. Horseradish peroxidase and ™-amylase were successfully immobilised using CDI/ACA and diol/aldehyde chemistries with the CDI/ACA giving higher initial specific activities than the diol/aldehyde preparation. Alcohol dehydrogenase was also successfully immobilised but gave no measurable activity

    Cross-linked polyvinyl alcohol and method of making same

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    A film-forming polyvinyl alcohol polymer is mixed with a polyaldehyde-polysaccharide cross-linking agent having at least two monosaccharide units and a plurality of aldehyde groups per molecule, perferably an average of at least one aldehyde group per monosaccharide units. The cross-linking agent, such as a polydialdehyde starch, is used in an amount of about 2.5 to 20% of the theoretical amount required to cross-link all of the available hydroxyl groups of the polyvinyl alcohol polymer. Reaction between the polymer and cross-linking agent is effected in aqueous acidic solution to produce the cross-linked polymer. The polymer product has low electrical resistivity and other properties rendering it suitable for making separators for alkaline batteries

    Influence of aerosol acidity on the chemical composition of secondary organic aerosol from β-caryophyllene

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    The secondary organic aerosol (SOA) yield of β-caryophyllene photooxidation is enhanced by aerosol acidity. In the present study, the influence of aerosol acidity on the chemical composition of β-caryophyllene SOA is investigated using ultra performance liquid chromatography/electrospray ionization-time-of-flight mass spectrometry (UPLC/ESI-TOFMS). A number of first-, second- and higher-generation gas-phase products having carbonyl and carboxylic acid functional groups are detected in the particle phase. Particle-phase reaction products formed via hydration and organosulfate formation processes are also detected. Increased acidity leads to different effects on the abundance of individual products; significantly, abundances of organosulfates are correlated with aerosol acidity. To our knowledge, this is the first detection of organosulfates and nitrated organosulfates derived from a sesquiterpene. The increase of certain particle-phase reaction products with increased acidity provides chemical evidence to support the acid-enhanced SOA yields. Based on the agreement between the chromatographic retention times and accurate mass measurements of chamber and field samples, three β-caryophyllene products (i.e., β-nocaryophyllon aldehyde, β-hydroxynocaryophyllon aldehyde, and β-dihydroxynocaryophyllon aldehyde) are suggested as chemical tracers for β-caryophyllene SOA. These compounds are detected in both day and night ambient samples collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS)

    Sorption kinetics for the removal of aldehydes from aqueous streams with extractant impregnated resins

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    The sorption kinetics for the removal aldehydes from aqueous solutions with Amberlite XAD-16 and MPP particles impregnated with Primene JM-T was investigated. A model, accounting for the simultaneous mass transfer and chemical reaction, is developed to describe the process. It is based on the analogy to the diffusion and reaction in a stagnant liquid sphere, but corrected for the porosity and particle properties influencing the diffusion. The developed model describes the kinetic behavior of the process in the low concentration region rather well. However, in the high concentration region, larger discrepancies are observed. Initially, the influence of the flow rate was investigated to eliminate the effect of the external mass transfer. The influence of the particle morphology was investigated for both physical and reactive sorption. Physical sorption experiments were used to determine the factor τ that takes the particle properties influencing the diffusion into account. It was shown that the diffusion is faster in XAD-16 than in MPP impregnated systems. Reaction rate constant kx was determined by fitting the model to the experimental data. Sorption of benzaldehyde appears to be significantly slower (kx ~ 10−4 l/mol s) than the sorption of pentanal (kx ~ 10−3 l/mol s) due to the slower chemical reaction. The influence of the particle size was investigated for the sorption of pentanal with XAD-16. It was observed that the particle size does influence the diffusion term, but does not have an effect on the reaction rate. On the other hand, the extractant loading influences the reaction rate slightly in the low concentration region, whereas the initial concentration of the solute has more pronounced effect

    Aldehyde dehydrogenase 1A1 and gelsolin identified as novel invasion-modulating factors in conditioned medium of pancreatic cancer cells

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    Conditioned medium (CM) from clonal sub-populations of the pancreatic cancer cell line, MiaPaCa-2 with differing invasive abilities, were examined for their effect on in vitro invasion. Conditioned medium from Clone #3 (CM#3) strongly promoted invasion, while CM from Clone #8 (CM#8) inhibited invasion in vitro. 2D DIGE followed by MALDI-TOF MS analysis of CM#3 and CM#8 identified 41 proteins which were differentially regulated; 27 proteins were down-regulated and 14 proteins up-regulated in the invasion-promoting CM#3 when compared to CM#8. Western blotting analysis confirmed the down-regulated expression of gelsolin and the up-regulation of aldehyde dehydrogenase 1A1 in CM#3. Down-regulation of aldehyde dehydrogenase 1A1 in Clone #3 CM and gelsolin levels in Clone #8 CM by siRNA transfection revealed an important involvement of these proteins in promoting and inhibiting invasion in these pancreatic cancer cell lines
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