Triptofano ir tirozino aminorūgščių funkcinės grupės – indolo ir fenolio žiedai, stabilizuoja baltymų tretinę struktūrą, sąveikauja su aktyviais centrais biomolekulėse, dalyvauja elektronų pernašos procesuose. Siekiant giliau suprasti kaip šios grupės sąveikauja, buvo sukonstruotos dirbtinės monosluoksninės struktūros, sudarytos iš susintetintų bifunkcinių junginių, turinčių galines tiolio ir indolo žiedo arba fenolio žiedo grupes ir gebančių formuoti savitvarkius monosluoksnius ant aukso, sidabro ir vario elektrodų. Jų savybės ištirtos Ramano, infraraudonosios ir suminio dažnio generacijos spektroskopijų metodais. Pagrindiniai darbo tikslai buvo nustatyti bifunkcinių alkantiolių struktūrą ir adsorbcijos ypatumus pradinėje monosluoksnio formavimosi stadijoje, elektrodo prigimties įtaką monosluoksnių struktūrai ir potencialo įtaką galinių funkcinių grupių savybėms. Paviršiaus sustiprintos Ramano spektroskopijos metodu pirmą kartą parodyta, kad pradinėse monosluoksnių formavimo stadijose metileno grupės sąveikauja su metalo paviršiumi. Darbe įrodyta, kad dėl sąveikos su metalu spektruose atsiranda žemesnio dažnio („minkšta“) CH juosta ties 2820 cm-1. Pirmą kartą parodyta, kad indolo žiedas sąveikauja su Ag paviršiumi, esant pakankamai neigiamiems potencialams ir tą sąveiką galima spektriškai atpažinti pagal W16 modos ties ~1010 cm-1 dažnio sumažėjimu iki ~ 1001 cm-1. Tiriant indolo žiedu terminuotus ir mišrius monosluoksnius su įterptomis oktadekantiolio molekulėmis nustatytas... [toliau žr. visą tekstą] / The indole and phenole rings comprise the main part of tryptophan and tyrosine side chains in proteins and play an important role in the stabilization of tertiary structure, interaction with active centers in biomolecules, and electron transfer phenomena. To get better insight into the interactions of these functional groups, the artificial monomolecular structures have been constructed from the synthesized bifuncional compounds with thiol and indole or phenole ring functional groups able to form self-assembled monolayers on gold, silver and copper electrodes. Properties of these monolayers were studied by Raman, infrared, and sum-frequency generation spectroscopies. The main tasks of this work were to assess the adsorption peculiarities of the bifunctional thiols at the initial stage of the monolayer formation, to determine the influence of the electrode nature on the monolayer structure, and to establish the potential influence on the properties of the terminal functional groups. It was demonstrated for the first time that at the initial stage of monolayer formation the methylene groups interact with the metal surface. Evidence for the metal-induced lowering of the C−H stretching mode frequency down to 2820 cm-1 was provided. It was demonstrated that indole ring interacts with the Ag electrode surface at sufficiently negative potentials and this interaction can be recognized from the downshift of the W16 mode from ~ 1010 cm-1 to ~ 1001 cm-1. Investigations of indole ring... [to full text]

The pathway of seawater ammonium assimilation and influence of light on amino acid synthesis remain unresolved in cnidarian symbioses. Labeled ammonium (10 μM 15NH4Cl) in seawater was used to trace the pathway of the incorporation into amino acids in host tissue, Zoanthus sp., and zooxanthellae, Symbiodinium microadriaticum. Freshly isolated zooxanthellae were exposed to 20 μM 15NH4Cl with coral homogenate to evaluate the role of host factors on amino acid synthesis. High performance liquid chromatography and mass spectrometry was used to measure percent labeling and concentrations of amino acids. In zooxanthellae, ammonium was assimilated into glutamine likely via glutamine synthetase and into glutamate via glutamine 2-oxoglutarate amidotransferase. Interrupting photosynthesis with DCMU did not inhibit glutamine and tryptophan synthesis however reduced the 15N-enrichment of glutamate, aspartate, and ornithine in zooxanthellae, as well as arginine, ornithine, and lysine in host tissue. Coral homogenate had little effect on the 15N-enrichment of glutamine, aspartate, and alanine in freshly isolated zooxanthellae. Evidence is presented to support the uptake of ammonium ions and data shows that glutamine and not glutamate is translocated to the coral host.

The objective of these studies was to determine the optimum standardized ileal digestible tryptophan to lysine (SID Trp:Lys) ratio for growing pigs fed both U.S.–type (corn–soybean meal) and non–U.S.–type (wheat–barley) diets. When feeding U.S.–type diets, average daily gain (ADG) and plasma urea nitrogen (PUN) concentrations improved as SID Trp:Lys ratios increased, yielding optimum ratios of 15.32% (P<0.001) and 15.25% (P<0.001), respectively. Averaging these resulted in an optimum SID Trp:Lys ratio of 15.29%. In non–U.S.–type diets, feeding increasing SID Trp:Lys ratios improved ADG and PUN, displaying optima of 15.99% (P=0.048) and 15.29% (P=0.054), respectively. This produced an average optimum SID Trp:Lys ratio of 15.64%. The final study included the other dietary essential amino acids (EAA) at a higher level, and ADG and PUN improved as SID Trp:Lys ratios increased, yielding optima of 17.93% (P<0.001) and 16.17% (P=0.009). This averaged to an optimum SID Trp:Lys ratio of 17.05%. Overall, diet composition did not affect the Trp:Lys requirement of growing pigs, however, feeding the other EAA at higher levels resulted in a higher estimated optimum SID Trp:Lys ratio. The optimum SID Trp:Lys ratio is estimated to lie between 15.29% and 17.05%.

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Little is known about the adaptation of livestock to repeated transport. This study determined how repeated transport affected calf feed intake, plasma cortisol (CORT), post-transport behavior, and the expression of immune-related genes. Thirty-six 4-month-old Holstein steer calves were housed in groups of six with each group randomly assigned to either transport (T) or control (C) treatments. The T calves were hauled for 6 h in a 7.3 m x 2.4 m goose-neck trailer, at an average density of 0.87 m2/calf, every 7 d for five consecutive weeks. Individual daily intake was determined using Calan gate feeders. Blood samples were obtained in the trailer or home pen via jugular venipuncture before loading, and after 2, 4, and 6 h of transport. Samples were analyzed for CORT, serotonin, tryptophan, and the gene expression of interleukin-4 (IL-4), interleukin-6 (IL-6), chemokine (C-X-C motif) receptor 2, interleukin-12, toll-like receptor-4, toll-like receptor-2, and 5-hydroxytryptamine receptor 2A in leukocytes. Behavior was recorded for transported calves at 5-min intervals for 1 h after return to their home pens. The C calves had a higher feed intake than T calves overall (P = 0.01), on the day of transport (P = 0.007), and the day after transport (P = 0.02). Pre-transport CORT concentrations did not differ by treatment (P = 0.77) or trial (P = 0.32). However, the T calves had higher response CORT concentrations than C calves during Transport 3 (P = 0.006), Transport 4 (P = 0.001) and Transport 5 (P = 0.02). The T calves had the highest response CORT concentrations after 2 h of transport and the lowest response CORT concentrations after 6 h of transport (P < 0.0001). Treatment did not affect gene expression in leukocytes, however, the expression of IL-4 (P = 0.01) and IL-6 (P = 0.05) was significantly lower after 2 h of transport than any other sampling times. These results suggest conflicting conclusions on whether the calves started to acclimate after being transported five times. However, CORT and gene expression differences occurred in response to the blood sampling regimen, which may provide insight to how calves acclimate during prolonged stress.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 6 uppsatser.

Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 10, 2010). Includes bibliographical references. Also issued in print.

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-26Bitstream added on 2014-06-13T18:44:41Z : No. of bitstreams: 1 hoshiba_ma_dr_jabo.pdf: 2741697 bytes, checksum: c38099a374c12bb742a6cd32c49e5ee4 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM) / Como estratégia para diminuir o alto índice de canibalismo na larvicultura do matrinxã, o uso do aminoácido essencial triptofano (Trp) parece promissor. O aminoácido é o precursor do neurotransmissor mono-amínico serotonina (5-hidroxitriptamina, 5-HT) e sua taxa de biossíntese no encéfalo são limitadas pela disponibilidade desse aminoácido, que parece ser uma das principais limitações para a síntese de 5-HT. A ingestão aumentada de triptofano eleva o nível do aminoácido no encéfalo, resultando em biossíntese aumentada de 5-HT no encéfalo de peixes. Esse por sua vez, é um neurotransmissor que media uma ampla variedade de comportamentos (agressão, medo e estresse em várias espécies, assim como na relação das interações sociais em muitos animais) por ação no sistema nervoso central e periférico. Assim, o presente estudo utilizou um aminoácido promotor da serotonina (triptofano), um inibidor seletivo da recaptação do neurotransmissor (fluoxetina) e um inibidor da síntese da serotonina (PCPA – paraclorofenilalanina), para verificar seu papel na mediação do comportamento agressivo e no desenvolvimento e sobrevivência larval de matrinxã no período de 1 a 12 dias após a eclosão. O triptofano foi fornecido juntamente com a ração, já a fluoxetina e a paraclorofenilalanina foram dissolvidos na água. Esse estudo foi realizado em duas condições de temperatura de cultivo, ou seja, com temperatura controlada em uma faixa de variação estreita (26-28°C) e com temperaturas variando de 19 a 31°C. Os resultados obtidos permitiram concluir que o uso do triptofano como suplemento na ração, pode ser uma alternativa viável na criação de matrinxã, pois aumentou o crescimento e a sobrevivência da prole, exceto na concentração mais alta (2,96g/100g ração). O uso de fluoxetina também aumentou a sobrevivência da prole, com redução do canibalismo, no... / The use of tryptophan as a strategy to reduce cannibalism in matrinxã hatchery seems promising. This amino acid is a precursor of the neurotransmitter serotonin (5-hidroxy-triptamine, 5-HT) whose biosynthesis rate in brain is limited by the amino acid availability. The increased intake of tryptophan by brain elevates the amino acid concentration in tissue resulting in higher serotonin production in fish. Serotonin is involved in the control of several types of behavior (aggression, fear, stress and social interaction in many animals) through effect in central and peripheral nervous systems. The present study evaluated the effect of a serotonin synthesis promoter (tryptophan), a selective inhibitor of serotonin reuptake (fluoxetine) and a selective inhibitor of serotonin synthesis (PCPA – paraclorofenilalanine) on the control of the aggressive behavior and on early development of matrinxã up to 12 days after hatching. Tryptophan was offered in the diet, and fluoxetine and PCPA in immersion solutions. The study was performed in two rearing temperatures, controlled temperature (26-28°C) and natural temperature without control (19 a 31°C). The results showed that tryptophan might be an alternative in matrinxã rearing since it promoted growth and enhanced survival of progeny, except in the highest concentration tested (2.96g/100g diet). Fluoxetine also enhanced larvae survival, with cannibalism reduction. The highest concentration (5000 ppb fluoxetine/L) reduced growth. The immunohistochemistry showed that the serotoninergig system is already developed in larvae and is similar to that of the juvenile fish of the same species. The temperature variation affected negatively the biological responses tested in this study, suggesting to be a stressor for fish. The PCPA did not show responses that could demonstrate a biological pattern