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1.
BMC Nutr ; 9(1): 41, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36890584

RESUMEN

BACKGROUND: There have been reports of isolated trace elements or vitamin deficiencies due to imbalanced diets, but no cases of selenium deficiency combined with scurvy have been reported. CASE PRESENTATION: A 7 year-old boy diagnosed with autistic spectrum disorder and mild psychomotor retardation, started an imbalanced diet including specific snacks and lacto-fermenting drinks from 5 years of age. Gingival hemorrhage and perioral erosions occurred at 6 years and 8 months of age, and he was referred to our hospital at 7 years of age. Slight tachycardia was found. Serum vitamin C level was 1.1 µg/dL (reference range (rr): 5-17.5 µg/dL), and selenium level was 2.8 µg/dL (rr: 7.7-14.8 µg/dL). He was diagnosed with both selenium deficiency and scurvy. Multivitamins and sodium selenate were administered for 12 days during admission, and symptoms of selenium deficiency and scurvy improved. After discharge, symptoms abated following the administration of multivitamins and regular administration of sodium selenate every 3 months. CONCLUSIONS: We report a complicated case of both selenium deficiency and scurvy due to an imbalanced diet of snacks and lacto-fermenting drinks in a 7-year-old boy with autism spectrum disorder. In patients with imbalanced diet, regular blood tests including trace elements and vitamins are necessary.

2.
Brain Dev ; 44(10): 672-680, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36058756

RESUMEN

BACKGROUND: Neonatal arterial ischemic stroke (NAIS) presents as seizures, including convulsions, subtle seizures, and apnea, and most patients experience neurological sequelae. Diagnosis is often delayed owing to low test sensitivity. The present study aimed to identify the early clinical diagnostic factors for NAIS in neonates with seizures. METHODS: The present study included 54 patients born at ≥36 weeks of gestation during the last 15 years who presented to the neonatal intensive care unit with neonatal seizures and underwent brain magnetic resonance imaging (MRI), 6 of whom were diagnosed with NAIS. Maternal background, clinical characteristics, and transcranial pulsed Doppler sonography results were retrospectively reviewed. RESULTS: Of the 24 patients who presented with convulsions or subtle seizures, 3 (13%) were diagnosed with NAIS and 3 of 30 patients (10%) presented with apnea. Maternal premature ventricular contraction complications were higher in the NAIS group than in the non-NAIS group (p = 0.01). NAIS group showed lower mean middle cerebral artery (MCA) resistance index (RI) was lower the non-NAIS group (p = 0.009), while the left-right RI difference (p = 0.019), mean MCA blood velocity (MnV; p = 0.04), and left-right MnV difference (p < 0.001) in cerebral blood flow velocities (CBFVs) were higher in the NAIS group. CONCLUSIONS: Our results revealed that maternal arrhythmia may be a diagnostic factor for NAIS in neonates with seizures. Early brain MRI is essential in neonates with seizures and findings of low MCA-RI, high MCA-MnV, or high left-right difference in CBFVs to distinguish between NAIS and non-NAIS.


Asunto(s)
Enfermedades del Recién Nacido , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Recién Nacido , Humanos , Estudios Retrospectivos , Apnea/diagnóstico , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/complicaciones , Convulsiones/diagnóstico por imagen , Convulsiones/complicaciones , Ultrasonografía Doppler Transcraneal/efectos adversos
4.
Pediatr Int ; 64(1): e14993, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34528332

RESUMEN

BACKGROUND: We investigated the pathogenic, clinical, and laboratory characteristics of children diagnosed with septic arthritis (SA) during the past 24 years and identified the risk factors for SA-related sequelae. METHODS: We retrospectively reviewed the records of patients admitted to Fukuoka University Hospital from 1997 to 2020. Causative pathogens were compared between the first (1997-2008) and second (2009-2020) periods. We also compared the clinical and laboratory characteristics in patients with known or unknown pathogens, and in patients with or without sequelae. RESULTS: A total of 37 patients with SA were identified, including 28 patients (76%) in the first period and nine patients (24%) in the second period. Sixteen of 37 patients (43%) were younger than 2 years, including two neonates. Pathogens were identified in 25 (68%) of 37 patients. Patients with known pathogens had a significantly higher C-reactive protein level on admission than those with unknown pathogens (P < 0.05). The predominant pathogen was Staphylococcus aureus (38%, 14/37). Although S. aureus and Hemophilus influenzae type b (Hib) were predominant pathogens in the first period, Hib was not found in the second period. Six (16%) of 37 patients with SA experienced sequelae. Moreover, the risk factors for the development of sequelae were significantly associated with infection at age <1 month and delayed surgical treatment (>4 days). CONCLUSIONS: The incidence of SA had decreased dramatically in the second period, and Hib was no longer the predominant pathogen. Earlier surgical drainage should be performed in neonates with SA.


Asunto(s)
Artritis Infecciosa , Haemophilus influenzae tipo b , Osteomielitis , Infecciones Estafilocócicas , Artritis Infecciosa/diagnóstico , Artritis Infecciosa/epidemiología , Artritis Infecciosa/terapia , Niño , Progresión de la Enfermedad , Humanos , Lactante , Recién Nacido , Osteomielitis/diagnóstico , Estudios Retrospectivos , Infecciones Estafilocócicas/complicaciones , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus
5.
Pediatr Int ; 64(1): e14949, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34390093

RESUMEN

BACKGROUND: Invasive candidiasis (IC) is a leading cause of morbidity and mortality in preterm infants. The objective of this study was to determine the prevalence of IC infection in newborns in the neonatal intensive care unit (NICU) of a tertiary hospital in Japan, and to identify specific predisposing factors for IC. METHODS: We retrospectively collected data on demographics, clinical characteristics, and outcomes of infants with IC, who were discharged from a tertiary NICU in Japan between January 2009 and December 2020. We compared predisposing factors associated with the occurrence of early-onset IC (EOIC < 72 h) and late-onset IC (LOIC ≥ 72 h) with those of early-onset and late-onset bacterial sepsis. RESULTS: Between January 2009 and December 2020, 3,549 infants were admitted to the NICU, including 344 extremely-low birthweight (ELBW) infants. Eleven infants (including nine ELBW infants) had IC (incidence 0.31%), and the mortality rate of IC was 0%. Four (36%) infants had EOIC and seven (64%) had LOIC. All those with EOIC presented with skin lesions and 86% with LOIC had thrombocytopenia. Maternal vaginal Candida colonization was a more specific predisposing factor for EOIC, while gestational age <26 weeks, broad-spectrum antibiotic use, prior bacterial infection, prior gastrointestinal (GI) surgery, and GI diseases were more specific predisposing factors for LOIC. CONCLUSIONS: The findings suggest that maternal vaginal Candida colonization and skin lesions in ELBW infants may contribute to early recognition of EOIC. LOIC should be suspected if ELBW infants with several predisposing factors of LOIC have thrombocytopenia.


Asunto(s)
Candidiasis Invasiva , Trombocitopenia , Candidiasis , Candidiasis Invasiva/diagnóstico , Candidiasis Invasiva/epidemiología , Candidiasis Invasiva/microbiología , Femenino , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Unidades de Cuidado Intensivo Neonatal , Estudios Retrospectivos
6.
F S Sci ; 2(1): 13-23, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-35559760

RESUMEN

OBJECTIVE: To examine the effect of Ureaplasma parvum (U. parvum) infection on mouse sperm motility, structure, and fertilizing ability and on embryo development. DESIGN: In vitro model of the effects of U. parvum serovar 3 infection on mouse sperm. SETTING: Basic research laboratory. INTERVENTION(S): None. ANIMALS: Mice. MAIN OUTCOME MEASURE(S): Mouse sperm motility was examined using the swim-up method, and their motility parameters were analyzed using the sperm motility analysis system. Localization and invasion of U. parvum were observed with fluorescence, confocal, and scanning electron microscopy. After in vitro fertilization with U. parvum-infected sperm, the quality of the fertilized egg and embryo development were assessed. RESULT(S): U. parvum was attached and internalized into mouse sperms and localized mainly at the sperm head and midpiece. U. parvum-infected mouse sperms exhibited decreased motility in a dose- and duration-dependent manner. Electron micrographs revealed that U. parvum infection induced the aggregation and morphological destruction of mouse sperm. Infected mouse sperm transported U. parvum into the fertilized egg with reduced fertilization rates, and infected embryo development was impaired. CONCLUSION(S): U. parvum infection caused deterioration of the mouse sperm quality and its functions, which affected the fertilization rate and embryo development.


Asunto(s)
Infecciones por Ureaplasma , Ureaplasma , Animales , Desarrollo Embrionario , Fertilización , Masculino , Ratones , Motilidad Espermática , Espermatozoides
7.
Inflamm Bowel Dis ; 17(11): 2235-50, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21987297

RESUMEN

BACKGROUND: Probiotics have been clinically administered to improve intestinal damage in some intestinal inflammations. However, probiotic treatments are not always effective for these intestinal disorders because live bacteria must colonize and maintain their activity under unfavorable conditions in the intestinal lumen when displaying their functions. This study investigated the physiological functions of a heat-killed body of a novel probiotic, Lactobacillus brevis SBC8803, on the protection of intestinal tissues, the regulation of cytokine production, the improvement of intestinal injury, and the survival rate of mice with dextran sodium sulfate (DSS)-induced colitis. METHODS: Heat shock protein (Hsp) induction and mitogen-activated protein kinase (MAPK) phosphorylation in intestinal epithelia by heat-killed L. brevis SBC8803 were examined by Western blotting. The barrier function of intestinal epithelia was measured with [(3) H]-mannitol flux in the small intestine under oxidant stress. The effects of the bacteria on improving epithelial injury and cumulative survival rate were investigated with a DSS colitis model. RESULTS: Heat-killed L. brevis SBC8803 induced Hsps, phosphorylated p38 MAPK, regulated the expression of tumor necrosis factor alpha (TNF-α), interleukin (IL)-1ß and IL-12, and improved the barrier function of intestinal epithelia under oxidant stress. The induction of Hsp and the protective effect were negated by p38 MAPK inhibitor. These functions relieve intestinal impairments and improve the survival rate in mice with lethal colitis. CONCLUSIONS: The administration of heat-killed L. brevis SBC8803 helps to successfully maintain intestinal homeostasis, while also curing intestinal inflammation. A therapeutic strategy using heat-killed bacteria is expected to be beneficial for human health even in conditions unsuitable for live probiotics because the heat-killed body is able to exhibit its effects without the requirement of colonization.


Asunto(s)
Colitis/mortalidad , Calor , Enfermedades Intestinales/microbiología , Enfermedades Intestinales/prevención & control , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Animales , Western Blotting , Células Cultivadas , Colitis/inducido químicamente , Colitis/microbiología , Sulfato de Dextran/toxicidad , Humanos , Interleucina-12/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Enfermedades Intestinales/patología , Levilactobacillus brevis/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Quinasas Activadas por Mitógenos/genética , Probióticos/uso terapéutico , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Tasa de Supervivencia , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
8.
Theor Appl Genet ; 122(1): 199-210, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20827457

RESUMEN

Traits conferring brewing quality are important objectives in malting barley breeding. Beer foam stability is one of the more difficult traits to evaluate due to the requirement for a relatively large amount of grain to be malted and then the experimental costs for subsequent brewing trials. Consequently, foam stability tends to be evaluated with only advanced lines in the final stages of the breeding process. To simplify the evaluation and selection for this trait, efficient DNA makers were developed in this study. Previous studies have suggested that the level of both of the foam-associated proteins Z4 and Z7 were possible factors that influenced beer foam stability. To confirm the relationship between levels of these proteins in beer and foam stability, 24 beer samples prepared from malt made from 10 barley cultivars, were examined. Regression analyses suggested that beer proteins Z4 and Z7 could be positive and negative markers for beer foam stability, respectively. To develop DNA markers associated with contents of proteins Z4 and Z7 in barley grain, nucleotide sequence polymorphisms in barley cultivars in the upstream region of the translation initiation codon, where the promoter region might be located were compared. As a result, 5 and 23 nucleotide sequence polymorphisms were detected in protein Z4 and protein Z7, respectively. By using these polymorphisms, cleaved amplified polymorphic sequence (CAPS) markers were developed. The CAPS markers for proteins Z4 and Z7 were applied to classify the barley grain content of 23 barley cultivars into two protein Z4 (pZ4-H and pZ4-L) and three protein Z7 (the pZ7-H, pZ7-L and pZ7-L2) haplotypes, respectively. Barley cultivars with pZ4-H showed significantly higher levels of protein Z4 in grain, and those with pZ7-L and pZ7-L2 showed significantly lower levels of protein Z7 in grain. Beer foam stability in the cultivars with pZ4-H and pZ7-L was significantly higher than that with pZ4-L and pZ7-H, respectively. Our results indicate that these CAPS markers provide an efficient selection tool for beer foam stability in barley breeding programs.


Asunto(s)
Cerveza/análisis , Cruzamiento , Mapeo Cromosómico/métodos , Hordeum/genética , Secuencia de Bases , Codón/genética , Grano Comestible/genética , Electroforesis en Gel de Agar , Marcadores Genéticos , Variación Genética , Haplotipos/genética , Datos de Secuencia Molecular , Proteínas de Plantas/genética , Reacción en Cadena de la Polimerasa , Alineación de Secuencia
9.
Biosci Biotechnol Biochem ; 74(7): 1479-82, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20622437

RESUMEN

The gene expression and enzyme activity of superoxide dismutase, catalase, and ascorbate peroxidase in the space-grown barley were not significantly different from those of the ground-grown barley. Cu2+ reducing and radical scavenging activities in an extract of the space-grown barley were lower than those of the ground-grown barley by 0.7 fold, suggesting that the space environment does not induce oxidative stress, and reduces antioxidant capacity in plants.


Asunto(s)
Antioxidantes/metabolismo , Medio Ambiente Extraterrestre , Hordeum/crecimiento & desarrollo , Hordeum/metabolismo , Estrés Oxidativo , Congelación , Regulación Enzimológica de la Expresión Génica/efectos de la radiación , Hordeum/genética , Hordeum/efectos de la radiación , Estrés Oxidativo/efectos de la radiación , Especies Reactivas de Oxígeno/metabolismo
10.
J Agric Food Chem ; 57(6): 2493-502, 2009 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-19243103

RESUMEN

Nelson Sauvin (NS) is a unique hop cultivar that was bred and grown in New Zealand. This hop gives a specific flavor (exotic fruit-like, white wine-like) to finished beers. However, the key compounds of this flavor have not yet been identified. We have attempted to identify the specific flavor compounds derived from NS. We focused on certain volatile thiols that are well-known to contribute to wine flavors, especially Sauvignon Blanc. The product made from NS (NS product) lost its specific flavor by contact with copper. Copper is well-known as an absorber of thiols in the field of wine flavor investigations. Therefore, it might point to the existence of thiols. We analyzed the NS product by GC-FPD, GC-olfactometry and GC-MS, and identified two new volatile thiols, 3-sulfanyl-4-methylpentan-1-ol (3S4MP), and 3-sulfanyl-4-methylpentyl acetate (3S4MPA). These compounds have a grapefruit-like and/or rhubarb-like odor, similar to that of Sauvignon Blanc. We quantified these compounds in the NS products and determined their thresholds. As a result, 3S4MP contained about 2-fold of its threshold in beers, and 3S4MPA was included below its threshold. However, it was confirmed that 3S4MP enhanced the flavors of 3S4MPA by synergy. Therefore, we concluded that both of the new volatile thiols would contribute to the specific odor of beers produced with NS.


Asunto(s)
Humulus/química , Compuestos de Sulfhidrilo/análisis , Cerveza/análisis , Cromatografía de Gases y Espectrometría de Masas , Humanos , Odorantes/análisis , Olfato , Especificidad de la Especie , Compuestos de Sulfhidrilo/química , Gusto , Terpenos/análisis , Volatilización
11.
J Agric Food Chem ; 56(18): 8664-71, 2008 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-18710245

RESUMEN

Foam stability is an important quality trait of beer. Our previous results of two-dimensional gel electrophoresis (2DE) analyses of beer proteins implied a relationship between barley dimeric alpha-amylase inhibitor-1 (BDAI-1) and beer foam stability as judged by the NIBEM-T analyzer. To develop a novel prediction method of beer foam stability under different conditions of barley cultivar and malt modification, multiple linear regression analysis was applied. The spot intensities of major beer proteins on 2DE gel were quantified and used as explanatory variables. The foam stabilities of 25 beer samples each brewed from malt with different malt modification in one of the three cultivars (cultivars A, B, and C) were explained by the spot intensities of BDAI-1 at the 5% significance level ( r = 0.421). Furthermore, two other major protein spots (b0 and b5) were observed on the 2DE gels of Japanese commercial beer samples with different foam stability. Then, multiple regression for foam stability was calculated using these three spot intensities as explanatory variables. As a result, 72.1% of the beer foam stability in 25 beer samples was explained by a novel multiple regression equation calculated using spot b0 and BDAI-1 as positive explanatory variables and spot b5 as a negative variable. To verify the validity of the multiple regression equation and the explanatory variables, the beer foam stability in practical beer samples was analyzed. As a result, 81.5% of the beer foam stability in 10 Japanese commercial beer samples was also explained by using spot b0 and BDAI-1 as positive explanatory variables and spot b5 as a negative variable. Mass spectrometry analyses followed by database searches revealed that protein spots b0 and b5 were identified as protein Z originated from barley and thioredoxin originated from yeast, respectively. These results confirm that BDAI-1 and protein Z are foam-positive factors and identify yeast thioredoxin as a possible novel foam-negative factor.


Asunto(s)
Cerveza/análisis , Proteínas Sanguíneas/análisis , Inhibidores Enzimáticos/análisis , Hordeum/química , Tiorredoxinas/análisis , alfa-Amilasas/antagonistas & inhibidores , Fenómenos Químicos , Química Física , Dimerización , Electroforesis en Gel Bidimensional , Proteínas Fúngicas/análisis , Modelos Lineales , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
12.
J Agric Food Chem ; 56(4): 1458-64, 2008 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-18237135

RESUMEN

The foam stability of beer is one of the important key factors in evaluating the quality of beer. The purpose of this study was to investigate the relationship between the level of malt modification (degradation of protein, starch, and so on) and the beer foam stability. This was achieved by examining foam-promoting proteins using two-dimensional gel electrophoresis (2DE). We found that the foam stability of beer samples brewed from the barley malts of cultivars B and C decreased as the level of malt modification increased; however, the foam stability of cultivar A did not change. To identify the property providing the increased foam stability of cultivar A, we analyzed beer proteins using 2DE. We analyzed three fractions that could contain beer foam-promoting proteins, namely, beer whole proteins, salt-precipitated proteins, and the proteins concentrated from beer foam. As a result, we found that in cultivar A, some protein spots did not change in any of these three protein fractions even when the level of malt modification increased, although the corresponding protein spots in cultivars B and C decreased. We analyzed these protein spots by peptide mass finger printing using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. As a result, all of these spots were identified as barley dimeric alpha-amylase inhibitor-I (BDAI-I). These results suggest that BDAI-I is an important contributor to beer foam stability.


Asunto(s)
Cerveza/normas , Hordeum , Proteínas de Plantas/química , alfa-Amilasas/antagonistas & inhibidores , Cerveza/análisis , Electroforesis en Gel Bidimensional , Hordeum/química , Hordeum/genética , Proteínas de Plantas/análisis , Desnaturalización Proteica , Especificidad de la Especie
13.
Plant Foods Hum Nutr ; 63(1): 21-5, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18074229

RESUMEN

This study investigated whether the consumption of a diet in which high-beta-glucan barley replaced rice would reduce the visceral fat area as well as the serum low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) in hypercholesterolemic Japanese men. A randomized, double-blinded, placebo-controlled intervention study was conducted in 44 hypercholesterolemic Japanese men with a body mass index (BMI) >22 kg/m2. The subjects were randomly assigned to groups consuming either rice (placebo group) or a mixture of rice and pearl barley with a high beta-glucan content (test group, 7.0 g beta-glucan per day) for 12 weeks. Blood samples were taken, and CT scan obtained before the trial and every four weeks during the trial. The pearl barley intake significantly reduced serum concentrations of LDL-C (P = 0.041) and TC (P = 0.037) during the trial. Significant differences between the test and placebo groups were found for the visceral fat (P = 0.039), BMI (P = 0.015), and waist circumference (P = 0.011) at the end point. The consumption of pearl barley with a high beta-glucan content reduces not only LDL-C but also visceral fat area.


Asunto(s)
Anticolesterolemiantes/uso terapéutico , Colesterol/sangre , Hordeum/química , Hipercolesterolemia/tratamiento farmacológico , Grasa Intraabdominal/efectos de los fármacos , Triglicéridos/sangre , beta-Glucanos/uso terapéutico , Adulto , Índice de Masa Corporal , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Método Doble Ciego , Humanos , Hipercolesterolemia/sangre , Grasa Intraabdominal/metabolismo , Japón , Masculino , Relación Cintura-Cadera
14.
Phytochemistry ; 68(11): 1530-6, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17499824

RESUMEN

Several d-amino acids have been identified in plants. However, the biosynthetic pathway to them is unclear. In this study, we cloned and sequenced a cDNA encoding a serine racemase from barley which contained an open reading frame encoding 337 amino acid residues. The deduced amino acid sequence showed significant identity to plant and mammalian serine racemases and contained conserved pyridoxal 5-phosphate (PLP)-binding lysine and PLP-interacting amino acid residues. The purified gene product catalyzed not only racemization of serine but also dehydration of serine to pyruvate. The enzyme requires PLP and divalent cations such as Ca(2+), Mg(2+), or Mn(2+), but not ATP, whereas mammalian serine racemase activity is increased by ATP. In addition to the results regarding the effect of ATP on enzyme activity and the phylogenetic analysis of eukaryotic serine racemases, the antiserum against Arabidopsis serine racemase did not form a precipitate with barley and rice serine racemases. This suggests that plant serine racemases represent a distinct group in the eukaryotic serine racemase family and can be clustered into monocot and dicot types.


Asunto(s)
Hordeum/enzimología , Proteínas de Plantas/genética , Racemasas y Epimerasas/genética , Adenosina Trifosfato/metabolismo , Secuencia de Aminoácidos , Cationes/metabolismo , Clonación Molecular , Hordeum/genética , Datos de Secuencia Molecular , Oryza/enzimología , Oryza/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Racemasas y Epimerasas/química , Racemasas y Epimerasas/metabolismo , Alineación de Secuencia , Análisis de Secuencia de Proteína
15.
Phytochemistry ; 67(7): 668-74, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16483618

RESUMEN

A cDNA encoding a homolog of mammalian serine racemase, a unique enzyme in eukaryotes, was isolated from Arabidopsis thaliana and expressed in Escherichia coli cells. The gene product, of which the amino acid residues for binding pyridoxal 5'-phosphate (PLP) are conserved in this as well as mammalian serine racemases, catalyzes not only serine racemization but also dehydration of serine to pyruvate. The enzyme is a homodimer and requires PLP and divalent cations, Ca2+, Mg2+, Mn2+, Fe2+, or Ni2+, at alkaline pH for both activities. The racemization process is highly specific toward L-serine, whereas L-alanine, L-arginine, and L-glutamine were poor substrates. The Vmax/Km values for racemase activity of L- and D-serine are 2.0 and 1.4 nmol/mg/min/mM, respectively, and those values for L- and D-serine on dehydratase activity are 13 and 5.3 nmol/mg/min/mM, i.e. consistent with the theory of racemization reaction and the specificity of dehydration toward L-serine. Hybridization analysis showed that the serine racemase gene was expressed in various organs of A. thaliana.


Asunto(s)
Arabidopsis/enzimología , Racemasas y Epimerasas/genética , Racemasas y Epimerasas/metabolismo , Alanina/química , Alanina/metabolismo , Arginina/química , Arginina/metabolismo , Catálisis , Cationes Bivalentes/farmacología , Dimerización , Escherichia coli/citología , Escherichia coli/genética , Glutamina/química , Glutamina/metabolismo , Hidroliasas/efectos de los fármacos , Hidroliasas/metabolismo , Concentración de Iones de Hidrógeno , Hibridación Fluorescente in Situ , Metales/farmacología , Datos de Secuencia Molecular , Fosfato de Piridoxal/metabolismo , Homología de Secuencia de Aminoácido , Serina/química , Serina/metabolismo , Estereoisomerismo , Especificidad por Sustrato
16.
Phytochemistry ; 65(17): 2439-46, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15381407

RESUMEN

A cDNA encoding adenylate isopentenyltransferase (AIPT) was cloned and sequenced from cones of hop (Humulus lupulus L.) by RT-PCR using oligonucleotide primers based on the conserved sequences of Arabidopsis thaliana AIPT isozymes (AtIPT1, AtIPT3, AtIPT4, AtIPT5, AtIPT6, AtIPT7 and AtIPT8). A full-length cDNA contained a 990-bp open reading frame encoding a molecular mass of 36,603 Da protein with 329 amino acids. Further, DNA sequencing of genomic DNA revealed absence of introns in the frame. On Southern blot analysis, a single AIPT gene was detected in H. lupulus, while RT-PCR analyses demonstrated that the gene was equally expressed in almost all tissues in the plant including roots, stems, leaves and cones. The deduced amino acid sequence shares 38-51% identity to those of A. thaliana AtIPTs. A recombinant enzyme expressed in Escherichia coli catalyzed isopentenyl transfer reaction from dimethylallyldiphosphate (DMAPP) to the N6 amino group of adenosine monophosphate (AMP), adenosine diphosphate (ADP) and adenosine triphosphate (ATP), respectively. In contrast, other nucleotides; guanosine monophosphate (GMP), inosine monophosphate (IMP), cytosine monophosphate (CMP), uridine monophosphate (UMP), were not accepted as a substrate. Interestingly, steady-state kinetic analyses revealed that the isopentenylation of ADP and ATP were more efficient than that of AMP as previously reported for A. thaliana AtIPT4. Finally, H. lupulus AIPT contains the putative ATP/GTP binding motif at the N-terminal as in the case of other known isopentenyltransferases. Site-directed mutagenesis of a conserved Asp62, located right after the ATP/GTP binding motif, with Ala resulted in complete loss of enzyme activity.


Asunto(s)
Transferasas Alquil y Aril , Humulus/enzimología , Transferasas Alquil y Aril/química , Transferasas Alquil y Aril/genética , Transferasas Alquil y Aril/metabolismo , Secuencia de Aminoácidos , Clonación Molecular , ADN Complementario/análisis , Regulación de la Expresión Génica de las Plantas , Humulus/química , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Aminoácido
17.
Biosci Biotechnol Biochem ; 68(5): 1142-5, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15170123

RESUMEN

The enzyme activities encoded in five cDNAs for chalcone synthase (CHS) homologs from hop were investigated. Only valerophenone synthase (VPS) and CHS_H1 showed both naringenin-chalcone and phlorisovalerophenone forming activity. Narigenin-chalcone production by VPS was much lower than by CHS_H1. Therefore, it is highly possible that flavonoid depends mainly on CHS_H1, while bitter acid biosynthesis depends mainly on VPS and CHS_H1.


Asunto(s)
Aciltransferasas/metabolismo , Humulus/enzimología , Acilcoenzima A/metabolismo , Aciltransferasas/genética , Aciltransferasas/aislamiento & purificación , Flavanonas/biosíntesis , Humulus/genética
18.
J Plant Physiol ; 160(9): 1101-8, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-14593812

RESUMEN

The promoter region of the valerophenone synthase (VPS) gene was isolated from hop (Humulus lupulus). VPS, a member of the chalcone synthase (CHS) super-family, catalyzes the biosynthesis reaction of the hop resin that significantly accumulates in the cone's secretory gland called the "lupulin gland". The typical H-box and G-box sequences, which exist in many plants' CHS promoters and act as cis-elements for tissue specificity, UV-light induction, etc., were not found in the isolated VPS promoter, although the H-box-like sequence (CCTTACC, CCTAACC) and the core sequence (ACGT) of the G-box were observed. The transformation experiment using the VPS promoter-UIDA gene fusion revealed that the promoter acts not only in the lupulin gland but also in the glands of leaf and stem. On the other hand, the VPS promoter activity was not induced by UV-irradiation.


Asunto(s)
Aciltransferasas/genética , Genes de Plantas , Humulus/enzimología , Humulus/genética , Regiones Promotoras Genéticas , Fusión Artificial Génica , Secuencia de Bases , ADN de Plantas/genética , Expresión Génica/efectos de la radiación , Glucuronidasa/genética , Humulus/efectos de la radiación , Datos de Secuencia Molecular , Estructuras de las Plantas/enzimología , Estructuras de las Plantas/genética , Plantas Modificadas Genéticamente , Rayos Ultravioleta
19.
Biosci Biotechnol Biochem ; 67(5): 966-72, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12834272

RESUMEN

A cDNA encoding an O-methyltransferase (OMT) was isolated from salt-tolerant barley roots by subtraction hybridization with cDNAs of salt-tolerant barley roots as a tester cDNA and cDNAs of the salt-sensitive barley roots as a driver cDNA. The deduced amino acid sequence showed significant identity with plant caffeic acid/5-hydroxyferulic acid OMTs. Southern blot analysis showed that the OMT gene was a single copy in both salt-tolerant and -sensitive barley. The cloned gene was expressed in a wheat germ cell-free system to produce the OMT, which had methylating activity for caffeic acid. Northern blot analysis showed that the OMT gene was expressed constitutively in the salt-tolerant barley roots and the expression level was increased 1.5 times by salt stress, but the salt-sensitive barley showed no expression of the gene in roots and leaves.


Asunto(s)
Regulación Enzimológica de la Expresión Génica/genética , Regulación de la Expresión Génica de las Plantas/genética , Hordeum/enzimología , Hordeum/genética , Metiltransferasas/biosíntesis , Raíces de Plantas/enzimología , Cloruro de Sodio/farmacología , Secuencia de Aminoácidos , Northern Blotting , Southern Blotting , Mapeo Cromosómico , ADN Complementario/biosíntesis , ADN Complementario/genética , ADN de Plantas/biosíntesis , ADN de Plantas/genética , Metiltransferasas/genética , Datos de Secuencia Molecular , ARN de Planta/biosíntesis , ARN de Planta/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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