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Alanine mother liquor, a type of industrial waste from alanine fermentation, was used as a nitrogen source to produce docosahexaenoic acid (DHA) by Schizochytrium sp. B4D1. The results indicated that yeast extract could trigger the utilization of the alanine mother liquor. Additionally, the alanine can be quenched during the culture, which aids in DHA accumulation. The medium components were optimized via response surface methodology as follows: 99.98-g/L glucose, 0.05-g/L yeast extract and a 183.17 dilution factor of the alanine mother liquid (v/v, with an alanine content of 0.72 g/L) and 17.98% inoculum concentration (v/v). Finally, in a 50-mL shake-flask fermentation, the DHA yield was 2.29 g/L.

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Establishing the genetic basis that underlies craniofacial variability in natural populations is one of the main topics of evolutionary and developmental studies. One of the genes associated with mammal craniofacial variability is RUNX2, and in the present study we investigated the association between craniofacial length and width and RUNX2 across New World bats (Phyllostomidae) and primates (Catarrhini and Platyrrhini). Our results showed contrasting patterns of association between the glutamate/alanine ratios (Q/A ratio) and palate shape in these highly diverse groups. In phyllostomid bats, we found an association between shorter/broader faces and increase of the Q/A ratio. In New World monkeys (NWM) there was a positive correlation of increasing Q/A ratios to more elongated faces. Our findings reinforced the role of the Q/A ratio as a flexible genetic mechanism that would rapidly change the time of skull ossification throughout development. However, we propose a scenario in which the influence of this genetic adjustment system is indirect. The Q/A ratio would not lead to a specific phenotype, but throughout the history of a lineage, would act along with evolutionary constraints, as well as other genes, as a facilitator for adaptive morphological changes.

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O saco vitelino esta presente em todas as espécies de vertebrados e desempenha importantes funções no desenvolvimento do embrião até a fase de placentação. O objetivo deste estudo foi avaliar o funcionamento do saco vitelino de embriões bovinos atentando para os aspectos morfológicos, bioquímicos e moleculares e suas relações ultraestruturais, bioquímicas e moleculares. Foram avaliados 69 amostras de SVEB distribuídos da seguinte forma: Grupo I (23-27), Grupo II (28-32), Grupo III (33-37), Grupo IV (38-42), Grupo V (43-47) e Grupo VI (48-52) dais de gestação. Os resultados inferem que o saco vitelino de embriões bovinos apresenta atividade proliferativa durante os primeiros dois grupos analisados, a presença de apoptose e necrose foram encontrados nos grupos restantes. A presença de importantes metabolitos como a alanina, mio-inositol, taurina, colina, glicerofosfocolina, cadaverina, glutamato, glutamina, lactato, hidrouracila, creatina, creatinina, aspartato e lisina; e proteínas como filamentos de actina ou tubulina do citoesqueleto, histona, sub unidades da hemoglobina, HSP-β1, proteína ribossomal, marcadores da matrix extracelular vimentina, alfafetoproteina e transferrina. Estas proteínas estão relacionadas diretamente com a formação de metabólitos secundários e foram encontradas durante todos os períodos estudados, com exceção da alanina que foi identificada somente no grupo I, ativando diversas proteínas e metabolitos, que estão envolvidos em vias de sinalização que promovem a ativação dos mecanismos de morte celular programada e na diferenciação celular, as quais iniciam as etapas da involução do saco vitelino e de outras estruturas no embrião, e assim dar inicio à placentação.

The yolk sac is present in all vertebrate species, and plays important roles in the developing embryo until the arrival of the placenta. The objective of this study was to evaluate the functioning of the yolk sac of bovine embryos and how the morphological, biochemical and molecular related, one ultrastructural analysis, biochemical and molecular analysis was performed. For these purpose we evaluated 69 samples of YSBE distributed as follows: Group I (23- 27), Group II (28-32), Group III (33-37), Group IV (38-42), Group V (43-47) and Group VI (48-52) days of pregnancy. The results infer that the yolk sac of bovine embryos has proliferative activity during the first two groups analyzed, the presence of apoptosis and necrosis were found in the remaining groups. The presence of major metabolites such as alanine, myo-inositol, taurine, choline, glicerofosfocolina, cadaverine, glutamate, glutamine, lactate, hydrouracile, creatine, creatinine, aspartate and lysine, proteins such as tubulin and actin cytoskeleton, histone, subunits of hemoglobin, HSP-β1, ribosomal protein, vimentin, markers of extracellular matrix, alpha-1-fetoprotein and transferrin. These proteins are related to the metabolites and were found throughout the study period, with the exception of alanine which was found in Group I, activating many proteins and metabolites that are involved in signaling pathways that trigger cell death mechanisms that originated the involution of the yolk sac, and thus give way to the beginning of placentation.

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Enantiomeric alanine was covalently grafted onto modified gold electrodes with mercaptopropionic acid and PAMAM dendrimers G4.0 with amine terminal groups. Cyclic voltammetric experiments in the presence of monocarboxylic ferrocene as a probe molecule proved that the alanine (Ala) was immobilized as a monolayer on the gold electrodes. Electron transfer to Ru(NH3)6Cl3 in solutions of different pH was studied by cyclic voltammetry (CV). Changes in solution pH resulted in the variation of the charge state of the terminal group and surface pKa values were estimated on the basis of these results. Because of electrostatic interactions between the positive charged groups on the electrode surface and the Ala, enantioselective recognition was possible. The interaction between enantiomers can be proven with molecular simulation. The electro-oxidation peak current was linearly dependent on Ala concentration over the range 0-10 microM with slopes between 143 and 187 microAcm(-2)/microM. The detection limit (3sigma) was 0.4059 microM for PAMAM G4.0-D(+)Ala-L(-)Ala and 0.4172 microM for PAMAM G4.0-L(-)Ala-D(+)Ala.

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The carboxyl-terminal segment of G protein-coupled receptors has one or more conserved cysteine residues that are potential sites for palmitoylation. This posttranslational modification contributes to membrane association, internalization, and membrane targeting of proteins. In contrast to other members of the glycoprotein hormone receptor family (the LH and thyroid-stimulating hormone receptors), it is not known whether the follicle-stimulating hormone receptor (FSHR) is palmitoylated and what are the effects of abolishing its potential palmitoylation sites. In the present study, a functional analysis of the FSHR carboxyl-terminal segment cysteine residues was carried out. We constructed a series of mutant FSHRs by substituting cysteine residues with alanine, serine, or threonine individually and together at positions 629 and 655 (conserved cysteines) and 627 (nonconserved). The results showed that all three cysteine residues are palmitoylated but that only modification at Cys629 is functionally relevant. The lack of palmitoylation does not appear to greatly impair coupling to G(s) but, when absent at position 629, does significantly impair cell surface membrane expression of the partially palmitoylated receptor. All FSHR Cys mutants were capable of binding agonist with the same affinity as the wild-type receptor and internalizing on agonist stimulation. Molecular dynamics simulations at a time scale of approximately 100 nsec revealed that replacement of Cys629 resulted in structures that differed significantly from that of the wild-type receptor. Thus, deviations from wild-type conformation may potentially contribute to the severe impairment in plasma membrane expression and the modest effects on signaling exhibited by the receptors modified in this particular position.

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Free D-amino acids are implicated in several biological functions. This study examined the presence of D-alanine in Leishmania amazonensis. Measuring chiral amino acid content by high-performance liquid chromatography we detected a significant amount of free D-alanine in promastigotes of these parasites. D-alanine accounts for 8.9% of total free alanine and is found primarily in the soluble fraction. Specific racemization of L-alanine to D-alanine was detected in cell lysates and this enzyme activity was inhibited by D-cycloserine, an alanine racemase inhibitor. Furthermore, we were able to decrease this pool of D-amino acid by treating our cultures with D-cycloserine. We demonstrate for the first time the existence of a significant amount of free D-alanine in L. amazonensis and an alanine racemase activity present in cell lysates. The restriction of D-alanine to bacteria, some fungi and now in L. amazonensis opens a new perspective on treatment of diseases caused by these microorganisms.

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The participation of neuroendocrine factors present within the central nervous system in the regulation of hemolymph free amino acid (FAA) concentrations was examined in the freshwater shrimp Macrobrachium olfersii. Test shrimps were injected intramuscularly with homogenates prepared from the eyestalks (ES), ventral nerve cord (VNC), supraesophageal (SEG), or thoracic ganglia (TG) of donor shrimps previously exposed for 6 hr to a high-salinity medium (HSM, 21% salinity). After injection of the homogenate, the shrimps were maintained for up to 6 hr in either freshwater (FW) or HSM. Hemolymph was sampled by cardiac puncture and prepared for reverse phase HPLC, derivatizing the FAA with phenylisothiocyanate. An FAA profile was determined and the [FAA]:[Cl-] ratios for the four FAA present in highest concentration (Gly, Arg, Ala, and Pro for ES and VNC experiments; Glu, Leu, Ala, and Val for SEG and TG experiments) were obtained. Nonparametric analyses revealed specific, notable effects resulting from homogenate injection, e.g., ES homogenate increased [Pro]/[Cl-] ratios in FW-exposed shrimps; SEG homogenate increased [Glu]/[Cl-] and [Val]/[Cl-] ratios in HSM-exposed shrimps; and TG homogenate increased [FAA]/[Cl-] ratios for Glu, Leu, Ala, and Val in HSM-exposed shrimps. Total FAA concentrations decreased after exposure of the shrimps to HSM but were increased by the injection of ES homogenate in FW-exposed shrimps and by TG homogenate in HSM-exposed shrimps. The total [FAA]/[Cl-] ratio was also increased by TG homogenate in HSM-exposed animals. There were no clear effects on [Cl-] alone.(ABSTRACT TRUNCATED AT 250 WORDS)

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In order to evaluate the involvement of estrogen-progesterone (EP) in the effects of N-methyl-D-aspartate (NMDA) receptor stimulation on gonadotropin secretion during sexual development in female rats, NMDA (30 mg/kg sc) was administered to 16- and 30-day-old female rats pretreated with EP. NMDA administration induced increases in plasma LH concentration that were 13.6-fold and 94.5-fold higher, respectively, than those found after NMDA alone. The increase of LH levels induced by NMDA was accompanied by a significant enhancement of the content of GnRH in the anterior and preoptic hypothalamic areas and in the medial basal hypothalamus (APOA/MBH). EP potentiated this increase of GnRH induced by NMDA. NMDA increased plasma FSH levels at 16 days of age, and this increase was inhibited by EP treatment. In 30-day-old rats EP induced FSH release in response to NMDA. This release was not observed in rats treated only with NMDA. In 16-day-old rats EP induced an increase in the concentrations of aspartate, glutamate, and glycine in the anterior and preoptic hypothalamic areas and in the medial basal hypothalamus, the excitatory amino acids involved in NMDA neurotransmission. This effect was not observed in rats of 30 days of age. In summary, the present results show that during sexual maturation ovarian steroids potentiated the LH-releasing response to NMDA probably by acting at the hypothalamic level; furthermore, during sexual maturation there are changes in the response to EP of the hypothalamic concentrations of excitatory amino acids. These findings could be related to the neuroendocrine mechanisms regulating the onset of puberty and the sexual cycle in female rats.

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