Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Am J Emerg Med ; 65: 109-112, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36603355

RESUMEN

STUDY OBJECTIVE: To compare the efficacy and frequency of akathisia and dystonia between the dopamine antagonist headache medications olanzapine, metoclopramide and prochlorperazine. METHODS: This was a retrospective observational cohort study of patients presenting to a large urban level one trauma center between 2010 and 2018. Inclusion criteria was age ≥ 18 who presented to the emergency department with a chief complaint of headache who received either olanzapine, metoclopramide or prochlorperazine. The primary outcome was need for rescue medication. Secondary outcomes were receiving medication for either akathisia or dystonia. Logistic regression was used to identify differences between the three cohorts up to 72 h from initial presentation. RESULTS: There were 5643 patients who met inclusion criteria. Olanzapine was the most commonly used drug (n = 2994, 53%) followed by prochlorperazine (n = 2100, 37%) and metoclopramide (n = 549, 10%). After adjusting for age and gender, there were no differences in risk for receiving rescue therapy or developing akathisia or dystonia. CONCLUSION: During initial ED visit and up to 72 h after receiving olanzapine, metoclopramide or prochlorperazine, we found no difference in risk for requiring rescue medication or developing akathisia or dystonia.


Asunto(s)
Distonía , Trastornos Migrañosos , Humanos , Proclorperazina/uso terapéutico , Metoclopramida/uso terapéutico , Olanzapina/uso terapéutico , Distonía/tratamiento farmacológico , Estudios de Cohortes , Agitación Psicomotora/tratamiento farmacológico , Trastornos Migrañosos/tratamiento farmacológico , Cefalea/tratamiento farmacológico , Servicio de Urgencia en Hospital , Método Doble Ciego
2.
Am J Emerg Med ; 58: 114-119, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35679653

RESUMEN

BACKGROUND: Flexible bronchoscopy has been safely used for decades in ambulatory and critical care settings to aid in the diagnosis and treatment of tracheobronchial tree disorders. Although emergency physicians have the requisite skills to operate and interpret flexible bronchoscopy, no reports exist on the use of bronchoscopy by emergency physicians apart from endotracheal tube placement and confirmation. OBJECTIVE: The primary goal of this study was to describe the indications, outcomes and complications of flexible bronchoscopy performed by emergency physicians in an urban academic emergency department. METHODS: This was a single-center retrospective cohort study involving chart and video review of 146 patients over a 10.5-year study period. Patients of any age were included if they had been tracheally intubated or mechanically ventilated and underwent flexible bronchoscopy in the emergency department. After patients were identified, manual chart and video review was used to collect data on patient demographics, indications for intubation, indications for bronchoscopy, details of the bronchoscopy procedure, procedural findings, outcomes of the procedure, complications, provider training levels, and additional bronchoscopies performed after admission. The data was analyzed using descriptive statistics. RESULTS: 146 patients were included in the study and all bronchoscopies were performed or supervised by attending emergency physicians. After bronchoscopy, 24% of patients displayed improvement in oxygenation or lobar collapse while most patients had no change in clinical status. One patient had temporary hypoxemia after bronchoscopy. When another physician performed a subsequent bronchoscopy during admission, the findings were in agreement with the ED bronchoscopy 86% of the time. CONCLUSION: At our institution, emergency physicians can safely and effectively use flexible bronchoscopy to diagnose and treat critically ill patients.


Asunto(s)
Broncoscopía , Atelectasia Pulmonar , Broncoscopía/efectos adversos , Servicio de Urgencia en Hospital , Humanos , Intubación Intratraqueal/métodos , Estudios Retrospectivos
3.
Plants (Basel) ; 8(7)2019 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-31336665

RESUMEN

Water deficit stress (WDS)-tolerance in grain amaranths (Amaranthus hypochondriacus, A. cruentus and A. caudatus), and A. hybridus, their presumed shared ancestor, was examined. A. hypochondriacus was the most WDS-tolerant species, a trait that correlated with an enhanced osmotic adjustment (OA), a stronger expression of abscisic acid (ABA) marker genes and a more robust sugar starvation response (SSR). Superior OA was supported by higher basal hexose (Hex) levels and high Hex/sucrose (Suc) ratios in A. hypochondriacus roots, which were further increased during WDS. This coincided with increased invertase, amylase and sucrose synthase activities and a strong depletion of the starch reserves in leaves and roots. The OA was complemented by the higher accumulation of proline, raffinose, and other probable raffinose-family oligosaccharides of unknown structure in leaves and/or roots. The latter coincided with a stronger expression of Galactinol synthase 1 and Raffinose synthase in leaves. Increased SnRK1 activity and expression levels of the class II AhTPS9 and AhTPS11 trehalose phosphate synthase genes, recognized as part of the SSR network in Arabidopsis, were induced in roots of stressed A. hypochondriacus. It is concluded that these physiological modifications improved WDS in A. hypochondriacus by raising its water use efficiency.

4.
Food Sci Nutr ; 7(1): 3-13, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30680154

RESUMEN

BACKGROUND: Agave syrups are natural sweeteners that are highly desirable for human consumption because they have low glycemic index. In this work, we explored the potential of 1H-NMR-Chemometrics as a useful tool in the identification and differentiation of Agave syrups. Also, we evaluated the phytochemical screening and antioxidant capacity of Agave syrup compared to other natural sweeteners. RESULTS: The phytochemical screening stands out for Agave syrups containing higher levels of metabolites with antioxidant activity, mainly saponins, glycosides, and terpenoids. Agave syrup antioxidant activity was in a range from 10% to 53%, while the total phenolic content was from 24 to 300 EAG/100 g, and condensed tannins were between 240 and 1,900 mg CE/g. Additionally, 1H-NMR spectroscopy was used to characterize syrup profiles and chemometrics. PCA group analyses allowed the sweeteners' classification by origin and kind of Agave. CONCLUSION: Thus, we conclude that 1H-NMR and chemometrics can be used for identifying, differentiating, and classifying Agave syrups. Besides, Agave syrups contain significant amounts of antioxidative components and can be considered as an effective source of antioxidant.

5.
Genes Brain Behav ; 18(3): e12533, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30375183

RESUMEN

Binge methamphetamine (MA) users have higher MA consumption, relapse rates and depression-like symptoms during early periods of withdrawal, compared with non-binge users. The impact of varying durations of MA abstinence on depression-like symptoms and on subsequent MA intake was examined in mice genetically prone to binge-level MA consumption. Binge-level MA intake was induced using a multiple-bottle choice procedure in which mice were offered one water drinking tube and three tubes containing increasing concentrations of MA in water, or four water tubes (control group). In two studies, depression-like symptoms were measured using a tail-suspension test and a subsequent forced-swim test, after forced abstinence of 6 and 30 hours from a 28-day course of chronic MA intake. An additional study measured the same depression-like symptoms, as well as MA intake, after prolonged abstinence of 1 and 2 weeks. MA high drinking mice and one of their progenitor strains DBA/2J escalated their MA intake with increasing MA concentration; however, MA high drinking mice consumed almost twice as much MA as DBA/2J mice. Depression-like symptoms were significantly higher early after MA access was withdrawn, compared to levels in drug-naïve controls, with more robust effects of MA withdrawal observed in MA high drinking than DBA/2J mice. When depression-like symptoms were examined after 1 or 2 weeks of forced abstinence in MA high drinking mice, depression-like symptoms dissipated, and subsequent MA intake was high. The MA high drinking genetic mouse model has strong face validity for human binge MA use and behavioral sequelae associated with abstinence.


Asunto(s)
Estimulantes del Sistema Nervioso Central/efectos adversos , Depresión/genética , Metanfetamina/efectos adversos , Síndrome de Abstinencia a Sustancias/genética , Animales , Depresión/inducido químicamente , Depresión/fisiopatología , Modelos Animales de Enfermedad , Femenino , Masculino , Ratones , Ratones Endogámicos DBA , Síndrome de Abstinencia a Sustancias/fisiopatología
6.
Res Microbiol ; 168(8): 740-750, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28774774

RESUMEN

Saccharomyces cerevisiae is a model to understand basic aspects of protein glycosylation pathways. Although these metabolic routes have been thoroughly studied, there are still knowledge gaps; among them, the role of the MNT1/KRE2 gene family. This family is composed of nine members, with only six functionally characterized. The enzymes Ktr1, Ktr3, and Mnt1/Kre2 have overlapping activities in both O-linked and N-linked glycan synthesis; while Ktr2 and Yur1 participate exclusively in the elongation of the N-linked glycan outer chain. KTR6 encodes for a phosphomannosyltransferase that synthesizes the cell wall phosphomannan. Here, we aimed to establish the functional role of KTR4, KTR5 and KTR7 in the protein glycosylation pathways, by using heterologous complementation in Candida albicans null mutants lacking members of the MNT1/KRE2 gene family. The three S. cerevisiae genes restored defects in the C. albicans N-linked glycosylation pathway. KTR5 and KTR7 partially complemented a C. albicans null mutant with defects in the synthesis of O-linked glycans, and only KTR4 fully elongated the O-linked glycans like wild-type cells. Therefore, our results suggest that the three genes have a redundant activity in the S. cerevisiae N-linked glycosylation pathway, but KTR4 plays a major role in O-linked glycan synthesis.


Asunto(s)
Manosiltransferasas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimología , Candida albicans/genética , Candida albicans/metabolismo , Glicosilación , Manosiltransferasas/química , Manosiltransferasas/genética , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética
7.
Front Microbiol ; 8: 843, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28539922

RESUMEN

Sporothrix schenckii sensu stricto and S. brasiliensis are usually associated to sporotrichosis, a subcutaneous mycosis worldwide distributed. Comparative analyses between these two species indicate they contain genetic and physiological differences that are likely to impact the interaction with host cells. Here, we study the composition of the cell wall from conidia, yeast-like cells and germlings of both species and found they contained the same sugar composition. The carbohydrate proportion in the S. schenckii sensu stricto wall was similar across the three cell morphologies, with exception in the chitin content, which was significantly different in the three morphologies. The cell wall from germlings showed lower rhamnose content and higher glucose levels than other cell morphologies. In S. brasiliensis, the wall sugars were constant in the three morphologies, but glucose was lower in yeast-like cells. In S. schenckii sensu stricto cells most of chitin and ß1,3-glucan were underneath wall components, but in S. brasiliensis germlings, chitin was exposed at the cell surface, and ß1,3-glucan was found in the outer part of the conidia wall. We also compared the ability of these cells to stimulate cytokine production by human peripheral blood mononuclear cells. The three S. schenckii sensu stricto morphologies stimulated increased levels of pro-inflammatory cytokines, when compared to S. brasiliensis cells; while the latter, with exception of conidia, stimulated higher IL-10 levels. Dectin-1 was a key receptor for cytokine production during stimulation with the three morphologies of S. schenckii sensu stricto, but dispensable for cytokine production stimulated by S. brasiliensis germlings. TLR2 and TLR4 were also involved in the sensing of Sporothrix cells, with a major role for the former during cytokine stimulation. Mannose receptor had a minor contribution during cytokine stimulation by S. schenckii sensu stricto yeast-like cells and germlings, but S. schenckii sensu stricto conidia and S. brasiliensis yeast-like cells stimulated pro-inflammatory cytokines via this receptor. In conclusion, S. brasiliensis and S. schenckii sensu stricto, have similar wall composition, which undergoes changes depending on the cell morphology. These differences in the cell wall composition, are likely to influence the contribution of immune receptors during cytokine stimulation by human monocytes.

8.
Planta ; 245(2): 265-281, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27730409

RESUMEN

MAIN CONCLUSION: Biosynthesis of agave fructans occurs in mesontle vacuoles which showed fluctuations in FAZY activities and synthesized a diverse spectrum of fructooligosaccharide isomers. Agave tequilana Weber Blue variety is an important agronomic crop in Mexico. Fructan metabolism in A. tequilana exhibits changes in fructan content, type, degree of polymerization (DP), and molecular structure. Specific activities of vacuolar fructan active enzymes (FAZY) in A. tequilana plants of different age and the biosynthesis of fructooligosaccharides (FOSs) were analyzed in this work. Vacuoles from mesontle (stem) protoplasts were isolated and collected from 2- to 7-year-old plants. For the first time, agave fructans were identified in the vacuolar content by HPAEC-PAD. Several FAZY activities (1-SST, 6-SFT, 6G-FFT, 1-FFT, and FEH) with fluctuations according to the plant age were found in protein vacuolar extracts. Among vacuolar FAZY, 1-SST activities appeared in all plant developmental stages, as well as 1-FFT and FEH activities. The enzymes 6G-FFT and 6-SST showed only minimal activities. Lowest and highest FAZY activities were found in 2- and 6-year-old plants, respectively. Synthesized products (FOS) were analyzed by TLC and HPAEC-PAD. Vacuolar FAZYs yielded large FOS isomers diversity, being 7-year-old plants the ones that synthesized a greater variety of fructans with different DP, linkages, and molecular structures. Based on the above, we are proposing a model for the FAZY activities constituting the FOS biosynthetic pathways in Agave tequilana Weber Blue variety.


Asunto(s)
Agave/fisiología , Oligosacáridos/biosíntesis , Proteínas de Plantas/metabolismo , Vacuolas/metabolismo , Agave/metabolismo , Conformación de Carbohidratos , Metabolismo de los Hidratos de Carbono , Fructanos/metabolismo , Glicósido Hidrolasas/metabolismo , Hexosiltransferasas/metabolismo , Oligosacáridos/análisis , Oligosacáridos/química , Factores de Tiempo
9.
Front Microbiol ; 7: 1951, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27994582

RESUMEN

The fungal cell wall contains glycoproteins that interact with the host immune system. In the prominent pathogenic yeast Candida albicans, Pmr1 acts as a Golgi-resident ion pump that provides cofactors to mannosyltransferases, regulating the synthesis of mannans attached to glycoproteins. To gain insight into a putative conservation of such a crucial process within opportunistic yeasts, we were particularly interested in studying the role of the PMR1 homolog in a low-virulent species that rarely causes candidiasis, Candida guilliermondii. We disrupted C. guilliermondii PMR1 and found that loss of Pmr1 affected cell growth and morphology, biofilm formation, susceptibility to cell wall perturbing agents, mannan levels, and the wall composition and organization. Despite the significant increment in the amount of ß1,3-glucan exposed at the wall surface, this positively influenced only the ability of the mutant to stimulate IL-10 production by human monocytes, suggesting that recognition of both mannan and ß1,3-glucan, is required to stimulate strong levels of pro-inflammatory cytokines. Accordingly, our results indicate C. guilliermondii sensing by monocytes was critically dependent on the recognition of N-linked mannans and ß1,3-glucan, as reported in other Candida species. In addition, chemical remotion of cell wall O-linked mannans was found to positively influence the recognition of C. guilliermondii by human monocytes, suggesting that O-linked mannans mask other cell wall components from immune cells. This observation contrasts with that reported in C. albicans. Finally, mice infected with C. guilliermondii pmr1Δ null mutant cells had significantly lower fungal burdens compared to animals challenged with the parental strain. Accordingly, the null mutant showed inability to kill larvae in the Galleria mellonella infection model. This study thus demonstrates that mannans are relevant for the C. guilliermondii-host interaction, with an atypical role for O-linked mannans.

10.
Front Neurosci ; 10: 493, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27853417

RESUMEN

Binge/crash cycles of methamphetamine (MA) use are frequently reported by individuals suffering from MA use disorders. A MA binge is self-reported as multiple daily doses that commonly accumulate to 800 mg/day (~10 mg/kg/day for a 170 pound human). A genetic animal model with a similar vulnerability to binge-level MA intake is missing. We used selectively bred MA high drinking (MAHDR) and low drinking (MALDR) mouse lines to determine whether several procedural variations would result in binge-level MA intake. Data were also collected in two progenitor populations of the MA drinking lines, the DBA/2J (D2) strain and the F2 cross of the D2 and C57BL/6J strains. The impact of 3 factors was examined: (1) concentration of MA in the two-bottle choice procedure used for selective breeding; (2) ratio of bottles containing MA vs. water, and (3) length of the withdrawal (or abstinence) period between MA drinking sessions. When MA concentration was progressively increased every 4 days in 20 mg/l amounts from 20 to 140 mg/l, maximum intake in MALDR mice was 1.1 mg/kg, whereas MAHDR mice consumed as much as 14.6 mg/kg. When these concentrations were tested in a multiple bottle choice procedure, the highest ratio of MA to water bottles (3:1) was associated with escalated MA intake of up to 29.1 mg/kg in MAHDR mice and 12.0 mg/kg in F2 mice; MALDR mice did not show a ratio-dependent escalation in MA intake. Finally, MAHDR and D2 mice were offered 3 bottles of MA vs. water at increasing concentrations from 20 to 80 mg/l, and tested under an intermittent 6-h withdrawal period, which was lengthened to 30 h (D2 mice) or to 30 or 78 h (MAHDR). D2 and MAHDR mice initially consumed similar amounts of 14-16 mg/kg MA, but D2 mice reduced their MA intake 3-fold after introduction of 30-h abstinence periods, whereas MAHDR mice retained their high level of intake regardless of withdrawal period. MAHDR mice provide a genetic model of binge-level MA intake appropriate for the study of associated MA-induced neurobiological changes and pharmaceutical treatments.

11.
Front Microbiol ; 7: 306, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27014229

RESUMEN

Candida parapsilosis is an important, emerging opportunistic fungal pathogen. Highly mannosylated fungal cell wall proteins are initial contact points with host immune systems. In Candida albicans, Och1 is a Golgi α1,6-mannosyltransferase that plays a key role in the elaboration of the N-linked mannan outer chain. Here, we disrupted C. parapsilosis OCH1 to gain insights into the contribution of N-linked mannosylation to cell fitness and to interactions with immune cells. Loss of Och1 in C. parapsilosis resulted in cellular aggregation, failure of morphogenesis, enhanced susceptibility to cell wall perturbing agents and defects in wall composition. We removed the cell wall O-linked mannans by ß-elimination, and assessed the relevance of mannans during interaction with human monocytes. Results indicated that O-linked mannans are important for IL-1ß stimulation in a dectin-1 and TLR4-dependent pathway; whereas both, N- and O-linked mannans are equally important ligands for TNFα and IL-6 stimulation, but neither is involved in IL-10 production. Furthermore, mice infected with C. parapsilosis och1Δ null mutant cells had significantly lower fungal burdens compared to wild-type (WT)-challenged counterparts. Therefore, our data are the first to demonstrate that C. parapsilosis N- and O-linked mannans have different roles in host interactions than those reported for C. albicans.

12.
Food Chem ; 167: 349-57, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25148997

RESUMEN

Agave syrups are gaining popularity as new natural sweeteners. Identification, classification and discrimination by infrared spectroscopy coupled to chemometrics (NIR-MIR-SIMCA-PCA) and HPAEC-PAD of agave syrups from natural sweeteners were achieved. MIR-SIMCA-PCA allowed us to classify the natural sweeteners according to their natural source. Natural syrups exhibited differences in the MIR spectra region 1500-900 cm(-1). The agave syrups displayed strong absorption in the MIR spectra region 1061-1,063 cm(-1), in agreement with their high fructose content. Additionally, MIR-SIMCA-PCA allowed us to differentiate among syrups from different Agave species (Agavetequilana and Agavesalmiana). Thin-layer chromatography and HPAEC-PAD revealed glucose, fructose, and sucrose as the principal carbohydrates in all of the syrups. Oligosaccharide profiles showed that A. tequilana syrups are mainly composed of fructose (>60%) and fructooligosaccharides, while A. salmiana syrups contain more sucrose (28-32%). We conclude that MIR-SIMCA-PCA and HPAEC-PAD can be used to unequivocally identify and classified agave syrups.


Asunto(s)
Agave/química , Fructosa/análisis , Oligosacáridos/análisis , Espectrofotometría Infrarroja/métodos , Edulcorantes/análisis
13.
Front Microbiol ; 6: 1527, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26793173

RESUMEN

The systemic infections caused by members of the Candida parapsilosis complex are currently associated to high morbility and mortality rates, and are considered as relevant as those caused by Candida albicans. Since the fungal cell wall is the first point of contact with the host cells, here we performed a comparison of this organelle in members of the C. parapsilosis complex, and its relevance during interaction with human peripheral blood mononuclear cells (PBMCs). We found that the wall of the C. parapsilosis complex members is similar in composition, but differs to that from C. albicans, with less mannan content and more ß-glucan and porosity levels. Furthermore, lectin-based analysis showed increased chitin and ß1,3-glucan exposure at the surface of C. parapsilosis sensu lato when compared to C. albicans. Yeast cells of members of the C. parapsilosis complex stimulated more cytokine production by human PBMCs than C. albicans cells; and this significantly changed upon removal of O-linked mannans, indicating this wall component plays a significant role in cytokine stimulation by C. parapsilosis sensu lato. When inner wall components were exposed on the wall surface, C. parapsilosis sensu stricto and C. metapsilosis, but not C. orthopsilosis, stimulated higher cytokine production. Moreover, we found a strong dependency on ß1,3-glucan recognition for the members of the C. parapsilosis complex, but not for live C. albicans cells; whereas TLR4 was required for TNFα production by the three members of the complex, and stimulation of IL-6 by C. orthopsilosis. Mannose receptor had a significant role during TNFα and IL-1ß stimulation by members of the complex. Finally, we demonstrated that purified N- and O-mannans from either C. parapsilosis sensu lato or C. albicans are capable to block the recognition of these pathogens by human PBMCs. Together; our results suggest that the innate immune recognition of the members of the C. parapsilosis complex is differential of that reported for C. albicans. In addition, we propose that purified cell wall mannans can be used as antagonist to block specific receptors on innate immune cells.

14.
J Agric Food Chem ; 60(47): 11704-13, 2012 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-23072425

RESUMEN

Fructan, as reserve carbohydrate, supplies energy needs during vegetative development, thereby exhibiting variations in its content and composition. Fructan metabolism in Agave tequilana Blue variety from 2- to 7-year-old plants was analyzed in this work. Soluble carbohydrates were determined at all ages. Fructan (328-711 mg/g), sucrose (14-39 mg/g), fructose (11-20 mg/g), glucose (4-14 mg/g), and starch (0.58-4.98 mg/g) were the most abundant carbohydrates. Thin-layer chromatography exhibited that 2-5-year-old plants mainly stored fructooligosaccharides, while 6-7-year-old plants mainly contained long-chain fructans. The fructan degree of polymerization (DP) increased from 6 to 23 throughout plant development. The 7-year-old plants mainly stored highly branched agavins. Partially methylated alditol acetate analyzed by gas chromatography-mass spectrometry reveals that fructan molecular structures became more complex with plant age. For the first time, we report the presence of a large number of DP3 (seven forms), DP4 (eight forms), and DP5 (six forms) isomers for agave fructans. Overall, fructan metabolism in A. tequilana displays changes in its soluble carbohydrates, DP, type, and fructan structures stored, along its developmental cycle in the field.


Asunto(s)
Agave/crecimiento & desarrollo , Agave/metabolismo , Fructanos/metabolismo , Agave/química , Conformación de Carbohidratos , Fructanos/análisis , Fructanos/química , Fructosa/análisis , Glucosa/análisis , Estructura Molecular , Oligosacáridos/análisis , Almidón/análisis , Sacarosa/análisis , Factores de Tiempo
15.
PLoS One ; 7(4): e35878, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22558253

RESUMEN

Fructans are the main storage polysaccharides found in Agave species. The synthesis of these complex carbohydrates relies on the activities of specific fructosyltransferase enzymes closely related to the hydrolytic invertases. Analysis of Agave tequilana transcriptome data led to the identification of ESTs encoding putative fructosyltransferases and invertases. Based on sequence alignments and structure/function relationships, two different genes were predicted to encode 1-SST and 6G-FFT type fructosyltransferases, in addition, 4 genes encoding putative cell wall invertases and 4 genes encoding putative vacuolar invertases were also identified. Probable functions for each gene, were assigned based on conserved amino acid sequences and confirmed for 2 fructosyltransferases and one invertase by analyzing the enzymatic activity of recombinant Agave protein s expressed and purified from Pichia pastoris. The genome organization of the fructosyltransferase/invertase genes, for which the corresponding cDNA contained the complete open reading frame, was found to be well conserved since all genes were shown to carry a 9 bp mini-exon and all showed a similar structure of 8 exons/7 introns with the exception of a cell wall invertase gene which has 7 exons and 6 introns. Fructosyltransferase genes were strongly expressed in the storage organs of the plants, especially in vegetative stages of development and to lower levels in photosynthetic tissues, in contrast to the invertase genes where higher levels of expression were observed in leaf tissues and in mature plants.


Asunto(s)
Agave/enzimología , Hexosiltransferasas/metabolismo , Componentes Aéreos de las Plantas/enzimología , Proteínas de Plantas/metabolismo , beta-Fructofuranosidasa/metabolismo , Agave/genética , Secuencia de Aminoácidos , Clonación Molecular , Secuencia Conservada , ADN Complementario/análisis , ADN Complementario/biosíntesis , Exones , Fructanos/biosíntesis , Hexosiltransferasas/genética , Intrones , Datos de Secuencia Molecular , Filogenia , Pichia , Componentes Aéreos de las Plantas/genética , Proteínas de Plantas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Especificidad por Sustrato , Transcriptoma , beta-Fructofuranosidasa/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...