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1.
Euro Surveill ; 20(26)2015 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-26159307

RESUMO

A novel GII.P17-GII.17 variant norovirus emerged as a major cause of norovirus outbreaks from December 2014 to March 2015 in Japan. Named Hu/GII/JP/2014/GII.P17-GII.17, this variant has a newly identified GII.P17 type RNA-dependent RNA polymerase, while the capsid sequence displays amino acid substitutions around histo-blood group antigen (HBGA) binding sites. Several variants caused by mutations in the capsid region have previously been observed in the GII.4 genotype. Monitoring the GII.17 variant's geographical spread and evolution is important.


Assuntos
Substituição de Aminoácidos/genética , Infecções por Caliciviridae/genética , Surtos de Doenças , Disenteria/genética , Norovirus/classificação , Norovirus/genética , Infecções por Caliciviridae/epidemiologia , Proteínas do Capsídeo/genética , Disenteria/epidemiologia , Fezes/virologia , Genótipo , Humanos , Japão/epidemiologia , Norovirus/isolamento & purificação , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
2.
Heliyon ; 8(11): e11468, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36406717

RESUMO

Background: We previously reported a novel technique for fabricating dermo-epidermal junction (DEJ)-like micropatterned collagen scaffolds to manufacture an ex vivo produced oral mucosa equivalent (EVPOME) for clinical translation; however, more biomimetic micropatterns are required to promote oral keratinocyte-based tissue engineering/regenerative medicine. In addition, in-process monitoring for quality control of tissue-engineered products is key to successful clinical outcomes. However, evaluating three-dimensional tissue-engineered constructs such as EVPOME is challenging. This study aimed to update our technique to fabricate a more biomimetic DEJ structure of oral mucosa and to investigate the efficacy of optical coherence tomography (OCT) in combination with deep learning for non-invasive EVPOME monitoring. Methods: A picosecond laser-textured microstructure mimicking DEJ on stainless steel was used as a negative mould to fabricate the micropatterned collagen scaffold. During EVPOME manufacturing, OCT was applied twice to monitor the EVPOME and evaluate its epithelial thickness. Findings: Our moulding system resulted in successful micropattern replication on the curved collagen scaffold. OCT imaging visualised the epithelial layer and the underlying micropatterned scaffold in EVPOME, enabling to non-invasively detect specific defects not found before the histological examination. Additionally, a gradual increase in epithelial thickness was observed over time. Conclusion: These findings demonstrate the feasibility of using a stainless-steel negative mould to create a more biomimetic micropattern on collagen scaffolds and the potential of OCT imaging for quality control in oral keratinocyte-based tissue engineering/regenerative medicine.

3.
Psychol Med ; 40(6): 945-54, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19732477

RESUMO

BACKGROUND: The mildly learning disabled population has a three-fold elevated risk for schizophrenia. It has been proposed that in some individuals this cognitive limitation is a pre-psychotic manifestation of early onset schizophrenia. We examined clinical and neuroanatomical measures of a putative extended phenotype of schizophrenia in an adolescent population receiving special educational assistance. We predicted that people with intellectual impairment and schizotypal features would exhibit amygdala volume reduction as one of the neuroanatomical abnormalities associated with schizophrenia. METHOD: Assessment by clinical interview, neuropsychological assessment and magnetic resonance imaging scanning was carried out in 28 intellectually impaired individuals identified as being at elevated risk of schizophrenia due to the presence of schizotypal traits, 39 intellectually impaired controls and 29 non-intellectually impaired controls. Amygdala volume was compared in these three groups and the relationship between symptomatology and amygdala volume investigated. RESULTS: Right amygdala volume was significantly increased in the elevated risk group compared with the intellectually impaired controls (p=0.05). A significant negative correlation was seen between left amygdala volume and severity of negative symptoms within this group (p<0.05), but not in either control group. CONCLUSIONS: Intellectually impaired subjects judged to be at elevated risk of schizophrenia on the basis of clinical assessment exhibit structural imaging findings which distinguish them from the generality of learning disabled subjects. Within this population reduced amygdala volume may be associated with negative-type symptoms and be part of an extended phenotype that reflects particularly elevated risk and/or early manifestations of the development of psychosis.


Assuntos
Tonsila do Cerebelo/patologia , Educação Inclusiva , Processamento de Imagem Assistida por Computador , Deficiências da Aprendizagem/diagnóstico , Imageamento por Ressonância Magnética , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Transtorno da Personalidade Esquizotípica/diagnóstico , Adolescente , Análise de Variância , Dominância Cerebral/fisiologia , Feminino , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/patologia , Deficiência Intelectual/psicologia , Inteligência/fisiologia , Entrevista Psicológica , Deficiências da Aprendizagem/patologia , Deficiências da Aprendizagem/psicologia , Masculino , Testes Neuropsicológicos/estatística & dados numéricos , Tamanho do Órgão/fisiologia , Fenótipo , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Psicometria , Fatores de Risco , Esquizofrenia/patologia , Transtorno da Personalidade Esquizotípica/patologia , Transtorno da Personalidade Esquizotípica/psicologia , Fatores Sexuais
4.
J Appl Microbiol ; 106(1): 118-29, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19120621

RESUMO

AIMS: To study the microbial community responsible for the reduction of the polluting load during aerobic digestion of pig slurry. METHODS AND RESULTS: We analysed bacterial succession by nonculture-based methods and determined the physicochemical parameters and polluting substances during 6 days of aerobic digestion. The bacterial subpopulations evolved by aeration, predominantly Bacillus spp., degraded organic matter and vigorously consumed oxygen, as indicated by low oxidation-reduction potential (ORP). In this phase, the volatile fatty acid (VFA) levels drastically decreased, and VFAs were almost depleted on day 4. Simultaneously, the ammonia concentration decreased to its lowest level on day 4; thereafter, it increased until the end of the process. After the decrease in the total organic carbon content in the supernatant of the decomposed slurry, the ORP increased (approximately 0 mV), and the microbial community showed an abundance of lineages belonging to the phylum Proteobacteria. CONCLUSIONS: Bacillus was the predominant member of the bacterial community driving the VFA-removal process. Their predominance was related to the presence of available carbon, including VFAs and changes in ORP. SIGNIFICANCE AND IMPACT OF THE STUDY: Information on the relationships among the involved microbes, polluting materials and physicochemical parameters will aid process design and retrofitting of the process.


Assuntos
Bactérias/isolamento & purificação , Biodegradação Ambiental , Esterco/microbiologia , Nitratos/análise , Nitrogênio/análise , Aerobiose/fisiologia , Animais , Bactérias/metabolismo , Contagem de Colônia Microbiana , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Esterco/análise , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/análise , Análise de Sequência de DNA , Suínos
5.
J Dent Res ; 85(1): 64-8, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16373683

RESUMO

The muscarinic receptor agonist pilocarpine is widely used as a sialogogue. It has been well-established that it also induces water intake in animals. However, the mechanisms underlying the relationships between these events are unknown. To address this problem, we examined water intake and parotid salivary secretion in conscious rats. Intraperitoneally injected pilocarpine increased both water intake and salivary secretion. Intracerebroventricularly injected pilocarpine also induced water intake, but not salivary secretion. Intracerebroventricularly applied atropine, a muscarinic receptor antagonist, suppressed the water intake produced by pilocarpine applied intraperitoneally and intracerebroventricularly. However, it did not affect the salivary secretion induced by pilocarpine applied peripherally. We conclude that peripherally applied pilocarpine affects the parotid glands and the thirst center in the central nervous system, while it may induce salivary secretion mainly via peripheral responses, but water intake mainly via the central nervous system.


Assuntos
Agonistas Muscarínicos/farmacologia , Pilocarpina/farmacologia , Salivação/efeitos dos fármacos , Sede/efeitos dos fármacos , Animais , Atropina/administração & dosagem , Atropina/farmacologia , Relação Dose-Resposta a Droga , Ingestão de Líquidos/efeitos dos fármacos , Injeções Intraperitoneais , Injeções Intraventriculares , Masculino , Agonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/farmacologia , Glândula Parótida/efeitos dos fármacos , Glândula Parótida/metabolismo , Pilocarpina/administração & dosagem , Ratos , Ratos Wistar , Fatores de Tempo
6.
Transplant Proc ; 38(10): 3184-8, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17175217

RESUMO

Transplantation of many tissues requires histocompatibility matching of human leukocyte antigens (HLA) to prevent graft rejection, to reduce the level of immunosuppression needed to maintain graft survival, and to minimize the risk of graft-versus-host disease, particularly in the case of bone marrow transplantation. However, recent advances in fields of gene delivery and genetic regulation technologies have opened the possibility of engineering grafts that display reduced levels of HLA expression. Suppression of HLA expression could help to overcome the limitations imposed by extensive HLA polymorphisms that restrict the availability of suitable donors, necessitate the maintenance of large donor registries, and complicate the logistics of procuring and delivering matched tissues and organs to the recipient. Accordingly, we investigated whether knockdown of HLA by RNA interference (RNAi), a ubiquitous regulatory system that can efficiently and selectively inhibit the expression of specific gene products, would enable allogeneic cells to evade immune recognition. For efficient and stable delivery of short hairpin-type RNAi constructs (shRNA), we employed lentivirus-based gene transfer vectors, which provide a delivery system that can achieve integration into genomic DNA, thereby permanently modifying transduced graft cells. Our results show that lentivirus-mediated delivery of shRNA targeting pan-Class I and allele-specific HLA can achieve efficient and dose-dependent reduction in surface expression of HLA in human cells, associated with enhanced resistance to alloreactive T lymphocyte-mediated cytotoxicity, while avoiding MHC-non-restricted killing. We hypothesize that RNAi-induced silencing of HLA expression has the potential to create histocompatibility-enhanced, and, eventually, perhaps "universally" compatible cellular grafts.


Assuntos
Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Linfócitos T/imunologia , Sequência de Bases , Linhagem Celular , Citotoxicidade Imunológica , Primers do DNA , Inativação Gênica , Técnicas de Transferência de Genes , Vetores Genéticos , HIV/imunologia , Humanos , Interferon gama/imunologia , Rim , Lentivirus , Interferência de RNA
7.
J Mol Biol ; 237(1): 163-4, 1994 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-8133516

RESUMO

Large crystals of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. 1011, a typical alkalophilic enzyme, have been obtained at room temperature using polyethylene glycol 3000 and 2-propanol as precipitant. They belong to the triclinic space group P1 with the following unit cell constants: a = 64.93 A, b = 74.45 A, c = 79.12 A, alpha = 85.2 degrees, beta = 105.0 degrees and gamma = 101.0 degrees. The crystallographic asymmetric unit seems to contain two molecules of CGTase, with crystal volume per protein mass (Vm) of 2.41 A3/Da and solvent content of 49% by volume. The crystals diffract to at least 2.0 A resolution and they are suitable for X-ray analysis.


Assuntos
Bacillus/enzimologia , Glucosiltransferases/química , Cristalização , Cristalografia por Raios X
8.
Plant Physiol ; 117(4): 1473-86, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9701602

RESUMO

Growth of a zone of maize (Zea mays L.) coleoptiles and pea (Pisum sativum L.) internodes was greatly suppressed when the organ was decapitated or ringed at an upper position with the auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) mixed with lanolin. The transport of apically applied 3H-labeled indole-3-acetic acid (IAA) was similarly inhibited by NPA. The growth suppressed by NPA or decapitation was restored by the IAA mixed with lanolin and applied directly to the zone, and the maximal capacity to respond to IAA did not change after NPA treatment, although it declined slightly after decapitation. The growth rate at IAA saturation was greater than the rate in intact, nontreated plants. It was concluded that growth is limited and controlled by auxin supplied from the apical region. In maize coleoptiles the sensitivity to IAA increased more than 3 times when the auxin level was reduced over a few hours with NPA treatment. This result, together with our previous result that the maximal capacity to respond to IAA declines in pea internodes when the IAA level is enhanced for a few hours, indicates that the IAA concentration-response relationship is subject to relatively slow adaptive regulation by IAA itself. The spontaneous growth recovery observed in decapitated maize coleoptiles was prevented by an NPA ring placed at an upper position of the stump, supporting the view that recovery is due to regenerated auxin-producing activity. The sensitivity increase also appeared to participate in an early recovery phase, causing a growth rate greater than in intact plants.

9.
J Cereb Blood Flow Metab ; 18(3): 281-7, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9498844

RESUMO

The novel neuronal nitric oxide synthase inhibitors, 1-(2-trifluoromethylphenyl)imidazole (TRIM) and 7-nitro indazole (7-NI), were used to investigate the role of nitric oxide in a model of transient focal cerebral ischemia in vivo. In halothane-anesthetized rats, the middle cerebral artery (MCA) was occluded for 2 hours using an intravascular thread and then reperfused for 22 hours before histologic evaluation. TRIM (10, 20, or 50 mg/kg), 7-NI (60 mg/kg), TRIM (50 mg/kg) plus L-arginine (300 mg/kg), or L-arginine (300 mg/kg) alone was administered intraperitoneally, either at 5 or 90 minutes after MCA occlusion. Immediate administration (5 minutes after MCA occlusion) of TRIM produced a dose-related reduction in lesion size, which was reversed with L-arginine coadministration. Similarly, delayed administration of TRIM (90 minutes after MCA occlusion, 50 mg/kg) decreased total lesion volume by 48.4% +/- 13.0% in comparison to a reduction of 39.3% +/- 10.9% when TRIM (50 mg/kg) was administered immediately (5 minutes) after occlusion. 7-NI (60 mg/kg) reduced the total lesion volume by 38.5% +/- 13.7% when administered immediately (5 minutes) after MCA occlusion, but had no effect when administration was delayed (90 minutes). Neither TRIM (50 mg/kg) nor 7-NI (60 mg/kg), administered 5 minutes after MCA occlusion, had any significant effect on mean arterial blood pressure throughout the ischemic period or for up to 10 minutes after reperfusion. These results indicate that immediate or delayed administration of the selective neuronal NOS inhibitor TRIM reduces the lesion volume after transient MCA occlusion. In contrast, only immediate administration of 7-NI reduces lesion volume.


Assuntos
Inibidores Enzimáticos/administração & dosagem , Imidazóis/administração & dosagem , Indazóis/administração & dosagem , Ataque Isquêmico Transitório/tratamento farmacológico , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Sobrevivência Celular/efeitos dos fármacos , Ataque Isquêmico Transitório/enzimologia , Ataque Isquêmico Transitório/patologia , Masculino , Neurônios/efeitos dos fármacos , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Sprague-Dawley
10.
DNA Res ; 4(5): 329-33, 1997 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-9455481

RESUMO

The nucleotide sequence of a 45,137-bp segment covering the 19 degrees and 23 degrees region in the 360 degrees map of the Bacillus subtilis genome was determined. This region contained 45 open reading frames (ORFs) including 7 which corresponded to the products of genes with known functions that had been previously sequenced. The known genes were: glpT and glpQ for glycerol utilization pathway; purT for a part of the purine synthesis pathway; mpr for an extracellular metalloprotease; pss and psd for the parts of the phospholipid synthesis pathway; and gltP for a glutamine transporter. Deduced amino acid sequences of the 22 newly identified ORFs showed significant homologies to known gene products in the database such as a Methicillin-resistant Staphylococcus aureus (MRSA) gene which is related to drug resistance, a two-component response regulator, a series of amino acid permeases, transcriptional regulators, beta-lactamase, the phosphotransferase system (PTS) enzyme II for sugar uptake, and the eukaryotic ECA39 gene which is associated with cancer and apoptosis, etc. The remaining 16 ORFs did not show any significant sequence similarities to known gene products in the database.


Assuntos
Bacillus subtilis/química , Bacillus subtilis/genética , Cromossomos Bacterianos/química , Cromossomos Bacterianos/genética , DNA Bacteriano/química , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sequência de Bases , Cosmídeos/química , Camundongos , Fases de Leitura Aberta , Reação em Cadeia da Polimerase , Ratos , Análise de Sequência , Análise de Sequência de DNA
11.
DNA Res ; 4(5): 325-8, 1997 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-9455480

RESUMO

As a part of the Bacillus subtilis genome sequencing project, we have determined a 25-kb sequence covering the 17 degrees-19 degrees region. This region contains 26 complete open reading frames (ORFs) including the alkA and adaA/B operon, which encode genes for adaptive response to DNA alkylation. A homology search for the newly identified 21 ORFs revealed that 4 of them exhibit a significant similarity to known proteins, e.g., methicillin-resistant Staphylococcus aureus (MRSA) protein homolog, proteins involved in chloramphenicol resistance, glucosamine synthase and an ABC transporter protein. The remaining 17 ORFs did not show any significant sequence similarities to known gene products in the database.


Assuntos
Bacillus subtilis/química , Bacillus subtilis/genética , Cromossomos Bacterianos/química , Cromossomos Bacterianos/genética , DNA Bacteriano/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sequência de Bases , Cosmídeos/química , Fases de Leitura Aberta , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
12.
FEBS Lett ; 268(1): 43-7, 1990 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-2116980

RESUMO

Muscarinic acetylcholine receptors purified from porcine atrium were phosphorylated, depending on the presence of agonists, by a protein kinase partially purified from porcine brain, which had similar properties to the beta-adrenergic receptor kinase. GTP-binding regulatory proteins (Go) had dual effects on the phosphorylation of muscarinic receptors, i.e. stimulation at lower concentrations and inhibition at higher concentrations. The stimulatory effect was reproduced with the beta gamma subunit of Go and the inhibitory effect with the combination of the alpha and beta gamma subunits.


Assuntos
Proteínas de Ligação ao GTP/fisiologia , Receptores Muscarínicos/fisiologia , Trifosfato de Adenosina/metabolismo , Animais , Atropina/farmacologia , Carbacol/farmacologia , Técnicas In Vitro , Substâncias Macromoleculares , Fosforilação , Transdução de Sinais , Relação Estrutura-Atividade , Suínos
13.
FEBS Lett ; 337(1): 66-70, 1994 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-8276116

RESUMO

A new photometric assay of the disproportionation activity of cyclodextrin glucanotransferase (CGTase) using 3-ketobutylidene-beta-2-chloro-4-nitrophenyl-maltopentaoside as the donor, proved that the transglycosylation reaction of CGTase was operated by a Ping-Pong Bi Bi mechanism. The values of the kcat/Km(acceptor) proved that the same configurations of free hydroxyl groups with those of D-glucopyranose at C2, C3 and C4 positions were required for the acceptors used by CGTase. The structure around C6 on acceptors was not essential for acceptor function, but it was recognized by CGTase, since the values of kcat/Km for D-xylose were smaller than that for D-glucose. The value of kcat/Km for maltose was about 20-times larger than that for D-glucose, indicating that at least two glucopyranosyl rings are recognized by the acceptor binding sites.


Assuntos
Glucosiltransferases/metabolismo , Bacillus/enzimologia , Sítios de Ligação , Metabolismo dos Carboidratos , Carboidratos/química , Carboidratos/farmacologia , Escherichia coli , Glucose/química , Glucose/metabolismo , Glucosídeos/metabolismo , Glicosilação , Hidrólise , Cinética , Maltose/química , Maltose/metabolismo , Conformação Molecular , Proteínas Recombinantes/metabolismo , Sorbose/química , Sorbose/metabolismo , Especificidade por Substrato , Xilose/química , Xilose/metabolismo
14.
FEBS Lett ; 296(1): 37-40, 1992 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-1346117

RESUMO

Comparison of the amino acid sequences of cyclodextrin glucanotransferases (CGTases) with those of alpha-amylases revealed that two Asp and one Glu residues, which are considered to be the catalytic residues in alpha-amylases, were also conserved in CGTases. To analyze the function of the three conserved amino acid residues in CGTases, site-directed mutagenesis was carried out. The three mutant CGTases, in which Asp229, Glu257 and Asp328 were individually replaced by Asn or Gln, completely lost both their starch-degrading and beta-cyclodextrin-forming activities, whereas another mutant CGTase, in which Glu264 was replaced by Gln, retained these activities. The three inactive enzymes retained the ability to be bound to starch. These results suggest that Asp229, Glu257 and Asp328 play an important role in the enzymatic reaction catalyzed by CGTase and that a similar catalytic mechanism is present in both CGTases and alpha-amylases.


Assuntos
Ácido Aspártico/genética , Bacillus/enzimologia , Glucosiltransferases/metabolismo , Glutamatos/genética , alfa-Amilases/metabolismo , Bacillus/genética , Sequência de Bases , Sítios de Ligação , Western Blotting , Eletroforese em Gel de Poliacrilamida , Glucosiltransferases/genética , Ácido Glutâmico , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , alfa-Amilases/genética
15.
FEBS Lett ; 384(3): 227-30, 1996 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-8617359

RESUMO

In rod photoreceptor cells, Ca2+-bound recoverin associates with disk membranes and inhibits light-dependent phosphorylation of rhodopsin. However, the functional significance of Ca2+-induced membrane association of recoverin has not been fully evaluated. We found that Ca2+-bound recoverin forms a complex with rhodopsin kinase preferentially at the membrane surface. Addition of increasing amounts of membranes promoted the membrane association of recoverin, and remarkably suppressed rhodopsin kinase activity. It was concluded that the Ca2+-recoverin-rhodopsin kinase complex is stabilized by membrane association, leading to effective suppression of the kinase activity.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Membrana Celular/metabolismo , Proteínas do Olho , Lipoproteínas , Proteínas do Tecido Nervoso , Proteínas Quinases/metabolismo , Rodopsina/metabolismo , Segmento Externo da Célula Bastonete/metabolismo , Animais , Cálcio/metabolismo , Cálcio/farmacologia , Bovinos , Membrana Celular/enzimologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Receptor Quinase 1 Acoplada a Proteína G , Proteínas de Ligação ao GTP/metabolismo , Hipocalcina , Fosforilação , Recoverina , Segmento Externo da Célula Bastonete/ultraestrutura , Quinases de Receptores Adrenérgicos beta
16.
FEBS Lett ; 197(1-2): 305-10, 1986 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-2419165

RESUMO

The primary structure of the alpha-subunit of the adenylate cyclase-inhibiting G-protein (Gi) has been deduced from the nucleotide sequence of cloned DNA complementary to the bovine cerebral mRNA encoding the polypeptide. A much higher degree of amino acid sequence homology is observed between the alpha-subunits of Gi and transducin (68%) than between those of Gi and the adenylate cyclase-stimulating G-protein (Gs) (43%) or between those of transducin and Gs (42%).


Assuntos
Inibidores de Adenilil Ciclases , DNA , Proteínas de Ligação ao GTP/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Química Encefálica , Bovinos , DNA Recombinante , Proteínas de Membrana/genética , Hibridização de Ácido Nucleico , Fragmentos de Peptídeos , Poli A/genética , RNA/genética , RNA Mensageiro , Transducina
17.
FEBS Lett ; 209(2): 367-72, 1986 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-3792556

RESUMO

The complete amino acid sequence of the porcine cardiac muscarinic acetylcholine receptor has been deduced by cloning and sequencing the cDNA. The tissue location of the RNA hybridizing with the cDNA suggests that this muscarinic receptor species represents the M2 subtype.


Assuntos
DNA , Miocárdio/metabolismo , Receptores Muscarínicos , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/metabolismo , Hibridização de Ácido Nucleico , Especificidade de Órgãos , Receptores Muscarínicos/genética , Suínos
18.
Br J Pharmacol ; 82(4): 839-51, 1984 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6478114

RESUMO

Muscarinic receptors from rat forebrain have been solubilized by Lubrol PX, lysophosphatidylcholine (LPC), digitonin and cholate/1 M sodium chloride. The overall level of solubilization was characterized using receptors prelabelled with an irreversible antagonist. The recovery of nondenatured soluble binding activity was estimated using reversible tritiated antagonists. All these detergents solubilized 60-85% of the total binding sites. In Lubrol PX most of the receptors were recovered in a denatured form. In the other detergents 30-90% of the solubilized receptors were stable and capable of binding reversible [3H]-antagonists with high affinity. The hydrodynamic properties of the soluble receptors have been examined by gel filtration and sucrose gradient centrifugation in H2O and D2O. The soluble receptors in Lubrol PX, lysophosphatidylcholine and cholate were, in general, heterogeneous as regards their molecular size. Estimates of the molecular weight after correction for bound detergent, varied from 82,000 to 134,000. Conditions were identified under which the receptor was largely monodisperse, and the estimates of molecular weight agreed with values (ca. 83,000) from sodium dodecylsulphate (SDS) polyacrylamide gel electrophoresis. The amount of bound detergent could not be calculated for the digitonin-muscarinic receptor complex which had an estimated overall median molecular weight of about 290,000. It is concluded that a subpopulation of muscarinic receptors from the rat forebrain is capable of existing in a monomeric soluble form and binding ligands. There is also evidence that complexes with other proteins can exist, but their specificity and functional relevance are not known.


Assuntos
Química Encefálica , Receptores Muscarínicos/isolamento & purificação , Animais , Centrifugação com Gradiente de Concentração , Ácido Cólico , Ácidos Cólicos , Cromatografia em Gel , Digitonina , Lisofosfatidilcolinas , Polidocanol , Polietilenoglicóis , Ratos , Solubilidade , Fatores de Tempo
19.
J Biochem ; 129(4): 593-8, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11275559

RESUMO

1-Deoxynojirimycin, a pseudo-monosaccharide, is a strong inhibitor of glucoamylase but a relatively weak inhibitor of cyclodextrin glucanotransferase (CGTase). To elucidate this difference, the crystal structure of the CGTase from alkalophilic Bacillus sp. 1011 complexed with 1-deoxynojirimycin was determined at 2.0 A resolution with the crystallographic R value of 0.154 (R(free) = 0.214). The asymmetric unit of the crystal contains two CGTase molecules and each molecule binds two 1-deoxynojirimycins. One 1-deoxynojirimycin molecule is bound to the active center by hydrogen bonds with catalytic residues and water molecules, but its binding mode differs from that expected in the substrate binding. Another 1-deoxynojirimycin found at the maltose-binding site 1 is bound to Asn-667 with a hydrogen bond and by stacking interaction with the indole moiety of Trp-662 of molecule 1 or Trp-616 of molecule 2. Comparison of this structure with that of the acarbose-CGTase complex suggested that the lack of stacking interaction with the aromatic side chain of Tyr-100 is responsible for the weak inhibition by 1-deoxynojirimycin of the enzymatic action of CGTase.


Assuntos
1-Desoxinojirimicina/metabolismo , Bacillus/enzimologia , Inibidores Enzimáticos/metabolismo , Glucosiltransferases/química , Glucosiltransferases/metabolismo , 1-Desoxinojirimicina/química , Acarbose/química , Acarbose/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Inibidores Enzimáticos/química , Glucana 1,4-alfa-Glucosidase/química , Glucana 1,4-alfa-Glucosidase/metabolismo , Glucosiltransferases/antagonistas & inibidores , Ligação de Hidrogênio , Maltose/metabolismo , Modelos Moleculares , Conformação Proteica , Água/metabolismo
20.
J Biochem ; 127(3): 383-91, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10731709

RESUMO

The product specificity of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. #1011 is improved to near-uniformity by mutation of histidine-233 to asparagine. Asparagine 233-replaced CGTase (H233N-CGTase) no longer produces alpha-cyclodextrin, while the wild-type CGTase from the same bacterium produces a mixture of predominantly alpha-, beta-, and gamma-cyclodextrins, catalyzing the conversion of starch into cyclic or linear alpha-1,4-linked glucopyranosyl chains. In order to better understand the protein engineering of H233N-CGTase, the crystal structure of the mutant enzyme complexed with a maltotetraose analog, acarbose, was determined at 2.0 A resolution with a final crystallographic R value of 0.163 for all data. Taking a close look at the active site cleft in which the acarbose molecule is bound, the most probable reason for the improved specificity of H233N-CGTase is the removal of interactions needed to form a compact ring like a-cyclodextrin.


Assuntos
Acarbose/química , Asparagina/química , Glucosiltransferases/química , Bacillus/enzimologia , Sítios de Ligação , Cristalografia por Raios X , Modelos Químicos , Modelos Moleculares , Mutação , Engenharia de Proteínas , Estrutura Terciária de Proteína
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