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1.
Biodegradation ; 33(1): 59-70, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34751871

RESUMEN

Phthalic acid esters are predominantly used as plasticizers and are industrially produced on the million ton scale per year. They exhibit endocrine-disrupting, carcinogenic, teratogenic, and mutagenic effects on wildlife and humans. For this reason, biodegradation, the major process of phthalic acid ester elimination from the environment, is of global importance. Here, we studied bacterial phthalic acid ester degradation at Saravan landfill in Hyrcanian Forests, Iran, an active disposal site with 800 tons of solid waste input per day. A di-n-butyl phthalate degrading enrichment culture was established from which Paenarthrobacter sp. strain Shss was isolated. This strain efficiently degraded 1 g L-1 di-n-butyl phthalate within 15 h with a doubling time of 5 h. In addition, dimethyl phthalate, diethyl phthalate, mono butyl phthalate, and phthalic acid where degraded to CO2, whereas diethyl hexyl phthalate did not serve as a substrate. During the biodegradation of di-n-butyl phthalate, mono-n-butyl phthalate was identified in culture supernatants by ultra-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry. In vitro assays identified two cellular esterase activities that converted di-n-butyl phthalate to mono-n-butyl phthalate, and the latter to phthalic acid, respectively. Our findings identified Paenarthrobacter sp. Shss amongst the most efficient phthalic acid esters degrading bacteria known, that possibly plays an important role in di-n-butyl phthalate elimination at a highly phthalic acid esters contaminated landfill.


Asunto(s)
Dibutil Ftalato , Ácidos Ftálicos , Biodegradación Ambiental , Dibutil Ftalato/análisis , Dibutil Ftalato/química , Dibutil Ftalato/metabolismo , Ésteres/metabolismo , Bosques , Humanos , Irán , Ácidos Ftálicos/metabolismo , Instalaciones de Eliminación de Residuos
2.
Ultrasound Obstet Gynecol ; 49(5): 637-642, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27240926

RESUMEN

OBJECTIVE: To assess the spectrum of associated anomalies, intrauterine course and outcome in fetuses with absent pulmonary valve syndrome (APVS). METHODS: All cases with a prenatal diagnosis of APVS at two centers over a period of 13 years were analyzed retrospectively. APVS was diagnosed in the presence of rudimentary or dysplastic pulmonary valve leaflets with to-and-fro blood flow in the pulmonary trunk on color and pulsed-wave Doppler ultrasound. Data on demographic characteristics, presence of associated conditions, Doppler studies and pregnancy outcome were reviewed. RESULTS: During the study period, 40 cases of APVS were diagnosed prenatally. Thirty-seven (92.5%) cases were associated with tetralogy of Fallot (TOF) and three (7.5%) had an intact ventricular septum. Patency of the ductus arteriosus (DA) was found in 17/37 (45.9%) TOF cases and in all three cases with an intact ventricular septum. Mean gestational age at diagnosis was 19.7 (range, 12-34) weeks with 10 (25.0%) cases (all with TOF) diagnosed in the first trimester. TOF was an isolated finding in 15 (37.5%) cases. Chromosomal anomalies, cardiac defects and extracardiac anomalies were present in 18 (45.0%), four (10.0%) and three (7.5%) cases, respectively. Among the 40 cases, there were 19 (47.5%) terminations of pregnancy, six (15.0%) intrauterine deaths, four (10.0%) neonatal deaths and 11 (27.5%) survivors. Patency of the DA, reversed flow during atrial contraction in the ductus venosus, umbilical artery or fetal middle cerebral artery, and hydrops/increased nuchal translucency thickness were significantly associated with non-survival. All 10 cases diagnosed in the first trimester had a patent DA and abnormal Doppler parameters, eight had hydrops and/or increased nuchal translucency, six were associated with trisomy 13 or 18 and none survived. CONCLUSION: APVS diagnosed in the first trimester is significantly associated with TOF, patency of the DA, abnormal Doppler parameters, lethal trisomies and intrauterine mortality. Cases of APVS with isolated TOF and agenesis of the DA have a better outcome than those with additional anomalies, with > 80% survival. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Diagnóstico Prenatal , Atresia Pulmonar/diagnóstico , Válvula Pulmonar/anomalías , Ecocardiografía Doppler , Femenino , Alemania , Cardiopatías Congénitas/diagnóstico , Cardiopatías Congénitas/diagnóstico por imagen , Cardiopatías Congénitas/mortalidad , Cardiopatías Congénitas/fisiopatología , Humanos , Embarazo , Resultado del Embarazo , Trimestres del Embarazo , Atresia Pulmonar/diagnóstico por imagen , Atresia Pulmonar/mortalidad , Atresia Pulmonar/fisiopatología , Análisis de Supervivencia , Ultrasonografía Prenatal
3.
S Afr Med J ; 108(6): 506-510, 2018 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-30004332

RESUMEN

BACKGROUND: Ureteral stenting is generally a theatre-based procedure that requires a multidisciplinary team and on-table imaging. Limited hospital bed numbers and theatre time in our centre in Cape Town, South Africa, have led us to explore an alternative approach. OBJECTIVES: To see whether outpatient insertion of ureteric stents under local anaesthesia without fluoroscopy was a possible and acceptable alternative to theatre-based ureteral stenting. METHODS: Ureteral stenting (double-J stents and ureteric catheters) was performed with flexible cystoscopy under local anaesthesia and chemoprophylaxis, but without fluoroscopic guidance, in an outpatient setting. Every patient had an abdominal radiograph and an ultrasound scan of the kidney after the procedure to confirm stent position. RESULTS: Three hundred and sixteen procedures (276 double-J stents and 40 ureteric catheters) were performed in 161 men and 155 women. The overall success rate for the procedures was 85.4%, independent of gender (p=0.87), age (p=0.13), type of device inserted (p=0.81) or unilateral/bilateral nature of the procedure (p=1.0). Procedures with a successful outcome were performed in a significantly (p<0.0001) shorter median time (10 minutes (interquartile range (IQR) 5 - 15)) than failed procedures (20 minutes (IQR 10 - 30)). Patients with a pain score of >5 experienced a significantly (p=0.02) greater proportion of failure (27.3%) than patients with a pain score of ≤5 (12.5%). Difficulties were encountered in 23.7% of procedures, with a significantly higher proportion being registered in failed interventions compared with successful ones (82.6% v. 13.7%; p<0.0001). CONCLUSIONS: The procedure was easily mastered and technically simple, and represents savings in cost, time and human resources in our setting.

4.
Immunobiology ; 193(2-4): 186-92, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8530142

RESUMEN

Human adenovirus can cause persistent infections in man. Implicated in this phenomenon is the early transcription unit 3 (E3) of the virus which encodes proteins that are primarily devoted to counteract the lytic attack by the host immune system: Several E3 proteins (14.7K, 10.4K and 14.5K) protect infected cells from the lytic activity of tumor necrosis factor alpha (TNF) while the most abundant E3 protein, E3/19K, inhibits lysis by cytotoxic T cells. E3/19K interacts with class I histocompatibility (MHC) antigens in the rough endoplasmic reticulum, thereby preventing transport of MHC molecules to the cell surface and, consequently, MHC-restricted T cell recognition. In addition, the 10.4K and 14.5K proteins downregulate cell surface expression of the epidermal growth factor receptor. Interestingly, adenovirus-mediated pneumonia in mice is accompanied by induction of TNF, a cytokine known to enhance MHC expression. We previously showed that TNF is unable to restore MHC class I expression in E3/19K transfected cells but rather leads to a further reduction of MHC antigens. This effect correlated with an increased production of E3/19K mRNA and protein. We now find in addition an upregulation of other E3 proteins in transfected as well as in infected cells. This coordinated upregulation of E3 proteins indicates that TNF stimulates the E3 promoter, probably by activating the transcription factor NF-kappa B. Thus, a novel interaction between the immune system and adenovirus is described in which the virus takes advantage of an immune mediator to promote expression of several immunosubversive proteins supporting its escape from immunosurveillance.


Asunto(s)
Proteínas E3 de Adenovirus/biosíntesis , Proteínas E3 de Adenovirus/efectos de los fármacos , Factor de Necrosis Tumoral alfa/fisiología , Animales , Humanos , Regulación hacia Arriba/inmunología
5.
Int J Nurs Stud ; 27(3): 303-13, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2199383

RESUMEN

A survey of the 'Human Relations Area Files' and ethnographic infant feeding literature from all cultures on the timing of infant feeding revealed that the practice of withholding colostrum from the infant was widespread. Data obtained from 120 cultures showed that in 50 cultures this delay in implementing breastfeeding was more than two days. In many groups, substitute prelacteal feeds were given, while in others, practices such as the use of purgatives exacerbated the risk of dehydration in the infant. The authors warn that nurses and midwives must be aware of the practice of withholding colostrum from the infant, and note that if a mother does not wish to breastfeed in the immediate postpartum, this does not necessarily mean that she wishes to bottle feed the infant.


PIP: Although early breastfeeding has many physiological and psychological benefits for a mother and her infant, in many cultural groups breastfeeding is delayed. This survey's information was obtained by conducting a literature search and be searching the Human Relations Area Files. All references to postpartal infant feeding were compiled and sorted according to the timing of the first feeding, and a list was made of the substitute prelacteal foods used in each culture. Data obtained from 120 cultures showed that 50 cultures initially withheld the infant from the breast for 48 hours or more, giving substitute prelacteal feeds. Reasons for withholding colostrum are varied. Most groups reported that colostrum was dirty, poisonous, or contaminated. Modern prelacteal feeding substituted for colostrum include water, water and glucose, or infant formula. Traditional substitute feedings, influenced by culture and available foodstuffs, were varied, but the most common technique was to let the nearest lactating relative nurse the child. Some cultural groups also have a tradition of giving purgatives to the newborn, a practice which exacerbates the dehydration effects of not breastfeeding. In encouraging early breastfeeding, caregivers should determine the mother's beliefs concerning early infant feeding, being sensitive to differences in culture and the perceived power of the caregiver in relation to the woman. Before providing advice on postpartum feeding, the caregiver should consider how the teachings will likely be received, avoiding cultural imposition and stereotyping of the patient. Most important is to remember that if a mother does not wish to breastfeed in the immediate postpartum, this does not necessarily mean that she never wishes to breastfeed.


Asunto(s)
Lactancia Materna , Calostro , Comparación Transcultural , Periodo Posparto , Femenino , Humanos , Lactante , Recién Nacido , Embarazo , Factores de Tiempo
6.
Vet Parasitol ; 166(3-4): 314-20, 2009 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-19783101

RESUMEN

Our aim was to develop a method for species diagnosis and to obtain data on the prevalence of Sarcocystis infections in cattle and water buffalo in the Son La Province of Northern Vietnam. Meat samples of naturally infected animals were examined by light and electron microscopy as well as by molecular methods. A PCR of part of the 18S rDNA gene followed by RFLP analysis was modified to detect infections with different Sarcocystis spp. in cattle and water buffaloes slaughtered in the Son La Province. It showed to be an economical method to detect multiple infections with Sarcocystis spp. Sequence analysis of the PCR amplicons was performed with selected samples and the results were compared with published sequences. With these methods the following Sarcocystis spp. were identified in cattle: Sarcocystis hirsuta, Sarcocystis cruzi and Sarcocystis hominis. Water buffaloes were infected with Sarcocystis fusiformis, S. cruzi, S. hominis and S. hirsuta. The results indicate that Sarcocystis spp. infecting cattle are also able to infect water buffaloes. So the validity of certain Sarcocystis spp. of water buffalo is discussed. Bovine lifestock in Northern Vietnam were commonly infected with Sarcocystis spp.


Asunto(s)
Búfalos/parasitología , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/parasitología , Sarcocystis/fisiología , Sarcocistosis/veterinaria , Animales , Bovinos , Femenino , Masculino , Carne/parasitología , Microscopía Electrónica de Transmisión , Reacción en Cadena de la Polimerasa/veterinaria , Polimorfismo de Longitud del Fragmento de Restricción , Prevalencia , ARN Ribosómico 18S/genética , Sarcocystis/genética , Sarcocystis/ultraestructura , Sarcocistosis/diagnóstico , Sarcocistosis/parasitología , Vietnam/epidemiología
7.
J Gen Virol ; 80 ( Pt 1): 97-100, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9934690

RESUMEN

Borna disease virus (BDV) replicates and transcribes its negative-sense RNA genome in the nucleus. The BDV phosphoprotein (P) is localized in the nucleus of infected cells and cells transfected with P expression constructs. To identify the nuclear localization signal (NLS) of P, COS-7 cells were transfected with wild-type or mutant forms of P fused with green fluorescent protein (GFP). Whereas GFP alone was exclusively cytoplasmic, P or P-GFP were nuclear. Analysis of carboxy- and amino-terminal truncation mutants of P indicated that amino acids (aa) 20-37 are sufficient to promote efficient nuclear accumulation of the fusion protein. Residual nuclear import of GFP was observed with portions of P including aa 33-134 or aa 134-201, suggesting the presence of additional NLS motifs. The major NLS of P appears to be bipartite. It consists of two basic aa domains, R22RER25 and R30PRKIPR36, separated by four non-basic aa, S26GSP29.


Asunto(s)
Virus de la Enfermedad de Borna/metabolismo , Señales de Localización Nuclear , Fosfoproteínas/metabolismo , Proteínas Virales/metabolismo , Secuencia de Aminoácidos , Animales , Virus de la Enfermedad de Borna/genética , Células COS , Núcleo Celular/metabolismo , Genes Reporteros , Proteínas Fluorescentes Verdes , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Datos de Secuencia Molecular , Señales de Localización Nuclear/genética , Fosfoproteínas/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Virales/genética
8.
Lancet ; 354(9194): 1973-4, 1999 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-10622306

RESUMEN

Human bornavirus RW98, whose genome differs by 3-4% from previous isolates, is almost identical to a rat-adapted laboratory strain. Other human bornaviruses are also strongly related to virus strains frequently used for experiments in the various laboratories reporting human bornavirus, questioning a human origin of isolates known to date.


Asunto(s)
Virus de la Enfermedad de Borna/genética , Animales , Enfermedad de Borna , Genoma Viral , Humanos , Trastornos Mentales/virología , Ratas , Homología de Secuencia de Ácido Nucleico , Proteínas Virales/genética
9.
Arch Virol ; 148(1): 45-63, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12536295

RESUMEN

Infection of newborn rats with Borna disease virus (BDV) leads to viral persistence in the central nervous system without overt signs of inflammation. Nevertheless, these rats display distinct behavioral and neurodevelopmental abnormalities. The molecular basis of the latter is still unknown. Using a cDNA array representing 1200 genes, we sought to identify cellular genes which are differentially expressed following perinatal BDV-infection. RNA samples prepared from different brain regions were analysed at various time points before or after BDV-induced defects become evident. In infected brains, we found upregulated expression of genes encoding brain fatty acid binding protein (B-FABP), beta2-microglobulin (beta2m) and, as described previously, the chemokine IP-10. Kinetic studies revealed sustained increased expression of B-FABP in infected frontal cortices beginning about three weeks p.i. Moreover, a slight transient increase of B-FABP expression in infected hippocampi was observed 3-5 weeks p.i. In situ hybridization studies combined with immunohistochemistry suggested that expression of beta2m was predominantly upregulated in glial cells and possibly also in some neurons. Employing cultured infected hippocampus slices and infected genetically modified mice, we provide evidence, that the observed upregulation of beta2m expression is not triggered by IFN-gamma, but rather by IFN-alpha/beta.


Asunto(s)
Enfermedad de Borna/genética , Virus de la Enfermedad de Borna/genética , Encéfalo/virología , Expresión Génica , Animales , Animales Recién Nacidos , Enfermedad de Borna/patología , Encéfalo/inmunología , Quimiocina CXCL10 , Quimiocinas/metabolismo , Quimiocinas CXC/metabolismo , Ácidos Grasos/metabolismo , Hipocampo/citología , Hipocampo/virología , Inflamación , Cinética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Técnicas de Cultivo de Órganos , Unión Proteica , Ratas , Ratas Endogámicas Lew , Regulación hacia Arriba , Microglobulina beta-2/metabolismo
10.
J Virol ; 74(12): 5655-8, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10823873

RESUMEN

Borna disease virus (BDV), the causative agent of severe meningoencephalitis in a wide variety of animal species, has been considered to be genetically invariable and to form a single type within the genus Bornavirus of the family Bornaviridae. BDV infections are of particular interest, because for the first time a virus infection appears to be linked to human psychiatric disorders. We now describe a new subtype of BDV isolated from a horse which was euthanatized due to severe, incurable neurological disease. The nucleotide sequence of this new strain, named No/98, differs from the reference strains by more than 15%, and the subtype is difficult to detect by standard reverse transcriptase PCR protocols. The nucleotide exchanges of the novel BDV isolate have surprisingly little effect on the primary structures of most viral proteins, with the notable exception of the X protein (p10), which is only 81% identical to its counterpart in reference strains. Our data indicate that the genome of BDV is far more variable than previously assumed and that naturally occurring subtypes may escape detection by currently used diagnostic assays.


Asunto(s)
Enfermedad de Borna/virología , Virus de la Enfermedad de Borna/clasificación , Virus de la Enfermedad de Borna/aislamiento & purificación , Encéfalo/virología , Enfermedades de los Caballos/virología , Animales , Enfermedad de Borna/diagnóstico , Virus de la Enfermedad de Borna/genética , Virus de la Enfermedad de Borna/fisiología , Núcleo Celular/virología , Células Cultivadas , Chlorocebus aethiops , Efecto Citopatogénico Viral , Genes Virales/genética , Genoma Viral , Enfermedades de los Caballos/diagnóstico , Caballos/virología , Inmunohistoquímica , Masculino , Datos de Secuencia Molecular , Sistemas de Lectura Abierta/genética , Filogenia , Conejos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Homología de Secuencia , Células Vero , Proteínas Virales/química , Proteínas Virales/genética , Replicación Viral
11.
J Virol ; 74(17): 7878-83, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10933695

RESUMEN

The RNA genome of Borna disease virus (BDV) shows extraordinary stability in persistently infected cell cultures. We performed bottleneck experiments in which virus populations from single infected cells were allowed to spread through cultures of uninfected cells and in which RNase protection assays were used to identify virus variants with mutations in a 535-nucleotide fragment of the M-G open reading frames. In one of the cell cultures, the major virus species (designated 2/1) was a variant with two point mutations in the G open reading frame. When fresh cells were infected with a low dose of a virus stock prepared from 2/1-containing cells, only a minority of the resulting persistently infected cultures contained detectable levels of the variant, whereas the others all seemed to contain wild-type virus. The BDV variant 2/1 remained stable in the various persistently infected cell cultures, indicating that the cells were resistant to superinfection by wild-type virus. Indeed, cells persistently infected with prototype BDV He/80 were also found to resist superinfection with strain V and vice versa. Our screen for mutations in the viral M and G genes of different rat-derived BDV virus stocks revealed that only one of four stocks believed to contain He/80 harbored virus with the original sequence. Two stocks mainly contained a novel virus variant with about 3% sequence divergence, whereas the fourth stock contained a mixture of both viruses. When the mixture was inoculated into the brains of newborn mice, the novel variant was preferentially amplified. These results provide evidence that the BDV genome is mutating more frequently than estimated from its invariant appearance in persistently infected cell cultures and that resistance to superinfection might strongly select against novel variants.


Asunto(s)
Virus de la Enfermedad de Borna/genética , Genoma Viral , Animales , Astrocitos/virología , Virus de la Enfermedad de Borna/patogenicidad , Células Cultivadas , Variación Genética , Ratones , Ratones Endogámicos , Datos de Secuencia Molecular , Mutación , Ratas , Ratas Endogámicas Lew , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN
12.
Arch Biochem Biophys ; 276(2): 390-5, 1990 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-2306102

RESUMEN

An NADPH:2'-hydroxydaidzein oxidoreductase (HDR) from elicitor-challenged soybean cell cultures was purified to apparent homogeneity by a five-step procedure. The purification procedure included affinity adsorption on Blue Sepharose and elution of the enzyme with NADP+. It was shown by gel filtration and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis that HDR consists of only one polypeptide, which has a Mr about 34,700. The pH optimum of the reaction was 7.0. Apparent Michaelis constants determined for 2'-hydroxydaidzein, 2'-hydroxyformononetin, and NADPH were, respectively, 50, 60, and 56 microM. A low conversion of 2'-hydroxygenistein to the corresponding isoflavanone was also observed but isoflavones lacking a 2'-hydroxyl group and various other flavonoids did not serve as substrates. Enzymatically derived 2'-hydroxydihydrodaidzein gave a positive CD spectrum at 328 nm, which shows its 3R stereochemistry. Antibodies against HDR were raised in rats.


Asunto(s)
Glycine max/enzimología , Oxigenasas/aislamiento & purificación , Extractos Vegetales/metabolismo , Western Blotting , Células Cultivadas , Cromatografía de Afinidad , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Cinética , Peso Molecular , Oxigenasas/metabolismo , Sesquiterpenos , Especificidad por Sustrato , Terpenos , Fitoalexinas
13.
J Bacteriol ; 183(6): 1899-908, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11222587

RESUMEN

The aerobic metabolism of benzoate in the proteobacterium Azoarcus evansii was reinvestigated. The known pathways leading to catechol or protocatechuate do not operate in this bacterium. The presumed degradation via 3-hydroxybenzoyl-coenzyme A (CoA) and gentisate could not be confirmed. The first committed step is the activation of benzoate to benzoyl-CoA by a specifically induced benzoate-CoA ligase (AMP forming). This enzyme was purified and shown to differ from an isoenzyme catalyzing the same reaction under anaerobic conditions. The second step postulated involves the hydroxylation of benzoyl-CoA to a so far unknown product by a novel benzoyl-CoA oxygenase, presumably a multicomponent enzyme system. An iron-sulfur flavoprotein, which may be a component of this system, was purified and characterized. The homodimeric enzyme had a native molecular mass of 98 kDa as determined by gel filtration and contained 0.72 mol flavin adenine dinucleotide (FAD), 10.4 to 18.4 mol of Fe, and 13.3 to 17.9 mol of acid-labile sulfur per mol of native protein, depending on the method of protein determination. This benzoate-induced enzyme catalyzed a benzoyl-CoA-, FAD-, and O2-dependent NADPH oxidation surprisingly without hydroxylation of the aromatic ring; however, H2O2 was formed. The gene (boxA, for benzoate oxidation) coding for this protein was cloned and sequenced. It coded for a protein of 46 kDa with two amino acid consensus sequences for two [4Fe-4S] centers at the N terminus. The deduced amino acid sequence showed homology with subunits of ferredoxin-NADP reductase, nitric oxide synthase, NADPH-cytochrome P450 reductase, and phenol hydroxylase. Upstream of the boxA gene, another gene, boxB, encoding a protein of 55 kDa was found. The boxB gene exhibited homology to open reading frames in various other bacteria which code for components of a putative aerobic phenylacetyl-CoA oxidizing system. The boxB gene product was one of at least five proteins induced when A. evansii was grown on benzoate.


Asunto(s)
Azoarcus/crecimiento & desarrollo , Azoarcus/metabolismo , Ácido Benzoico/metabolismo , Dioxigenasas , Aerobiosis , Secuencia de Aminoácidos , Azoarcus/genética , Clonación Molecular , Coenzima A Ligasas/genética , Coenzima A Ligasas/metabolismo , ADN Bacteriano/genética , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo , Datos de Secuencia Molecular , Consumo de Oxígeno , Oxigenasas/genética , Oxigenasas/metabolismo , Análisis de Secuencia de ADN , Especificidad por Sustrato
14.
J Immunol ; 153(4): 1626-36, 1994 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-8046235

RESUMEN

The E3/19K protein of human adenovirus type 2 binds to class I MHC Ags thereby interfering with their cell surface expression and Ag presentation function. Currently, it is unclear exactly which structure of MHC molecules is recognized by the E3/19K protein. We have previously demonstrated that the murine H-2Kd Ag is able to associate with E3/19K, whereas the allelic H-2Kk molecule is not. By using exon shuffling between Kd and Kk molecules, the alpha 1 and alpha 2 domains of MHC class I molecules were identified as essential structures for binding the viral protein. In this report, we have examined the contribution of individual amino acids within the alpha 2 domain of MHC for binding E3/19K. First, we show that within this domain the alpha-helical part is most important for the interaction with E3/19K. By using site-directed mutagenesis, Kd-specific amino acids were introduced into the alpha-helix of the alpha 2 domain of Kk. By using the expression of mutagenized proteins in E3/19K+ cells, we have identified Tyr 156 and Leu 180 as being essential for the association with the E3/19K protein. In addition, Kd residue Glu 163 seems to contribute to the complex formation. Furthermore, analysis of a panel of Kd/Dd recombinants indicates that a similar region in the Dd molecule, namely, the C-terminal half of the alpha 2 domain, affects binding to E3/19K. Combining these results with Ab binding data, we present two alternative models of how the adenovirus protein may bind to the alpha 1 and alpha 2 domains.


Asunto(s)
Proteínas E3 de Adenovirus/inmunología , Adenovirus Humanos/inmunología , Antígenos H-2/química , Proteínas E3 de Adenovirus/química , Proteínas E3 de Adenovirus/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Sitios de Unión , Cartilla de ADN/química , Antígenos H-2/metabolismo , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Unión Proteica , Estructura Secundaria de Proteína , Proteínas Recombinantes de Fusión , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Relación Estructura-Actividad
15.
Arch Microbiol ; 170(2): 120-31, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9683649

RESUMEN

Differential induction of enzymes involved in anaerobic metabolism of aromatic substrates was studied in the denitrifying bacterium Thauera aromatica. This metabolism is divided into (1) peripheral reactions transforming the aromatic growth substrates to the common intermediate benzoyl-CoA, (2) the central benzoyl-CoA pathway comprising ring-reduction of benzoyl-CoA and subsequent beta-oxidation to 3-hydroxypimelyl-CoA, and (3) the pathway of beta-oxidation of 3-hydroxypimelyl-CoA to three acetyl-CoA and CO2. Regulation was studied by three methods. 1. Determination of protein patterns of cells grown on different substrates. This revealed several strongly substrate-induced polypeptides that were missing in cells grown on benzoate or other intermediates of the respective metabolic pathways. 2. Measurement of activities of known enzymes involved in this metabolism in cells grown on different substrates. The enzyme pattern found is consistent with the regulatory pattern deduced from simultaneous adaptation of cells to utilisation of other aromatic substrates. 3. Immunological detection of catabolic enzymes in cells grown on different substrates. Benzoate-CoA ligase and 4-hydroxybenzoate-CoA ligase were detected only in cells yielding the respective enzyme activity. However, presence of the subunits of benzoyl-CoA reductase and 4-hydroxybenzoyl-CoA reductase was also recorded in some cell batches lacking enzyme activity. This possibly indicates an additional level of regulation on protein level for these two reductases.


Asunto(s)
Bacterias/enzimología , Hidrocarburos Aromáticos/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Acilcoenzima A/metabolismo , Anaerobiosis/fisiología , Proteínas Bacterianas/análisis , Benzoatos/metabolismo , Coenzima A/metabolismo , Coenzima A Ligasas/metabolismo , Electroforesis en Gel Bidimensional , Inducción Enzimática/efectos de los fármacos , Oxidorreductasas/metabolismo , Fenoles/metabolismo , Fenilacetatos/metabolismo , Fenilalanina/metabolismo , Tolueno
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