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1.
Nihon Shokakibyo Gakkai Zasshi ; 121(7): 580-588, 2024.
Artigo em Japonês | MEDLINE | ID: mdl-38987168

RESUMO

Improvement and worsening of portal hypertension after direct acting antiviral agent (DAA) treatment for hepatitis C virus-related cirrhosis have been reported, and a consensus remains elusive. In this study, we underscored on the intraperitoneal shunt formed via portal hypertension and examined how the shunt system confirmed by computed tomography (CT) changes before and after treatment in cases in which sustained virological response (SVR) was attained with DAAs. Of the cases in which we achieved an SVR of 24 with DAA treatment for hepatitis C virus-related cirrhosis at our hospital, 83 cases in which CT images were taken before and after treatment were investigated. If the intraperitoneal shunt diameter changed by 20% or more, it was analyzed as an increase or decrease. In 29 patients, intraperitoneal shunt enlargement was noted. When examining factors related to the increase, multivariate analysis detected the FIB4 index at the end of the DAA treatment. Conversely, only four cases were observed in which the size decreased. At the end of treatment, the FIB4 index was the most important factor in increasing the intraperitoneal shunt after DAA treatment for hepatitis C virus-related cirrhosis, and fibrosis was believed to be an influencing factor.


Assuntos
Antivirais , Hepatite C , Humanos , Antivirais/uso terapêutico , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Hepatite C/tratamento farmacológico , Hepatite C/complicações , Tomografia Computadorizada por Raios X , Hipertensão Portal , Cirrose Hepática/cirurgia
3.
Intern Med ; 62(10): 1473-1478, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36198599

RESUMO

Hiatal hernia is a common condition in elderly patients, but the additional presence of prolapse of the pancreas is extremely rare. We herein report an 89-year-old woman who presented with liver function disorders and abdominal pain. Her laboratory tests revealed cholestasis, and imaging examinations showed stenosis of the common bile duct pulled toward the hernia sac. She was diagnosed with a common bile duct stricture due to pancreatic herniation and underwent laparoscopic surgery. Our review of the literature identified three types of pancreatic herniations: asymptomatic, bile duct complication, and acute pancreatitis. Pancreatic head herniation tends to induce bile duct complications.


Assuntos
Colestase , Hérnia Hiatal , Pancreatite , Feminino , Humanos , Idoso , Idoso de 80 Anos ou mais , Pancreatite/diagnóstico , Constrição Patológica/complicações , Hérnia Hiatal/complicações , Hérnia Hiatal/diagnóstico por imagem , Hérnia Hiatal/cirurgia , Doença Aguda , Pâncreas , Colestase/diagnóstico por imagem , Colestase/etiologia , Colestase/cirurgia , Ductos Biliares , Hérnia , Fígado , Prolapso
4.
Intern Med ; 61(22): 3349-3354, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35466167

RESUMO

Shiitake mushrooms are edible mushrooms popular in East Asian cuisine. We herein report a 69-year-old man with abdominal distension and vomiting after ingesting several pieces of sautéed Shiitake mushrooms. Abdominal computed tomography (CT) revealed ring-shaped and crescent-shaped low-density objects (-100 to -300 Hounsfield units) in the ileum. Based on the specific shapes and CT numbers of the foreign bodies, he was diagnosed with small bowel obstruction due to Shiitake mushrooms. After conservative treatment, he passed four pieces of Shiitake mushrooms. Despite the rarity, the condition can be diagnosed before exploratory surgery by careful and detailed interpretation of CT findings.


Assuntos
Corpos Estranhos , Obstrução Intestinal , Cogumelos Shiitake , Masculino , Humanos , Idoso , Obstrução Intestinal/diagnóstico por imagem , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Tomografia Computadorizada por Raios X , Corpos Estranhos/diagnóstico , Intestino Delgado
5.
Surg Laparosc Endosc Percutan Tech ; 30(2): 164-168, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31972834

RESUMO

BACKGROUND: There are currently no guidelines concerning the advisability and timing of tube removal following percutaneous transhepatic gallbladder drainage (PTGBD). The present study aimed to assess the feasibility and risks of early removal of the PTGBD tube under the scenario of subsiding inflammation, patent cystic and common bile ducts, and absence of intraperitoneal leakage. METHODS: Patient background and outcomes were assessed retrospectively in 701 cases of acute cholecystitis treated with PTGBD. The median times until tube removal and tube dislodgement and the cumulative rates of tube dislodgement were calculated. RESULTS: Tube removal was performed in 275 patients after a median time of 16 days (range: 6 to 213 d); biliary peritonitis was observed in 2 patients following tube removal. Tubes were removed in 8 and 35 patients within 7 and 10 days, respectively. Tube dislodgement was observed in 82 patients after a median time of 12 days (range: 1 to 125 d). CONCLUSION: The present study suggests that drainage tube removal is safe and effective when performed after a short drainage period of 7 to 10 days if the criteria for the removal of the drainage tube were met.


Assuntos
Colecistite Aguda/cirurgia , Remoção de Dispositivo/efeitos adversos , Drenagem/efeitos adversos , Drenagem/instrumentação , Intubação/instrumentação , Complicações Pós-Operatórias/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peritonite/epidemiologia , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
6.
Intern Med ; 58(3): 369-374, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30210116

RESUMO

We herein report a 44-year-old man suffering from systemic edema due to protein-losing enteropathy (PLE) with superior mesenteric vein (SMV) obstruction and development of collateral veins, which subsequently proved to be a chronic result of thrombosis and a complication of Crohn's disease (CD). PLE was supposedly induced by both intestinal erosion and thrombosis-related lymphangiectasia, which was histologically proven in his surgically-resected ileal stenosis. Elemental diet and anti-TNFα agent improved his hypoalbuminemia after surgery. The rarity of the simultaneous coexistence of SMV obstruction and PLE and the precedence of these complications over typical abdominal symptoms of CD made the clinical course complex.


Assuntos
Doença de Crohn/complicações , Doença de Crohn/fisiopatologia , Veias Mesentéricas/fisiopatologia , Enteropatias Perdedoras de Proteínas/etiologia , Enteropatias Perdedoras de Proteínas/fisiopatologia , Trombose Venosa/fisiopatologia , Adulto , Doença de Crohn/terapia , Humanos , Masculino , Enteropatias Perdedoras de Proteínas/terapia , Resultado do Tratamento , Trombose Venosa/complicações , Trombose Venosa/etiologia , Trombose Venosa/terapia
7.
Food Nutr Res ; 61(1): 1325306, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28659733

RESUMO

Background: Isomaltodextrin (IMD) is a novel highly branched α-glucan and its function as a soluble dietary fiber is expected. Objective: The goal of this study was to evaluate the effects of IMD on postprandial glucose excursions in healthy people and to make the mechanism clear. Design: Twenty-nine subjects ingested a solution containing maltodextrin (MD) or sucrose with or without IMD. Fourteen subjects ingested a solution containing glucose with or without IMD. Blood glucose concentrations were then compared between the groups. Furthermore, in vitro digestion, inhibition of digestive enzymes, and glucose absorption tests were conducted. Results: IMD attenuated blood glucose elevation in the subjects with blood glucose excursions at the high end of normal following the ingestion of MD or sucrose or glucose alone. This effect of 5 g IMD was most clear. IMD was digested partially only by small intestinal mucosal enzymes, and maltase and isomaltase activities were weakly inhibited. Furthermore, IMD inhibited the transport of glucose from mucosal side to serosal side. Conclusions: IMD attenuated postprandial blood glucose, after the ingestion of MD or sucrose or glucose. As one of the mechanism, it was suggested that IMD inhibited the absorption of glucose on small intestinal mucosal membrane.

8.
Carbohydr Res ; 344(16): 2151-6, 2009 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-19740459

RESUMO

The bacterial strain PP710, isolated from soil and identified as Paenibacillus species, produced a low-digestibility alpha-glucan containing a large amylase-resistant portion. This alpha-glucan was obtained in high yields from maltodextrin (dextrose equivalent 3) by using the condensed culture supernatant of the strain as the enzyme preparation. The water-soluble dietary fiber content of the low-digestibility alpha-glucan was 80.2%, and showed resistance to a rat intestinal enzyme preparation. The alpha-glucan was found to be a novel highly branched alpha-glucan by acid hydrolysis, NMR analysis, gel permeation chromatography, methylation analysis, and enzymatic digestion.


Assuntos
Enzimas/metabolismo , Glucanos/biossíntese , Glucanos/química , Polissacarídeos/metabolismo , Animais , Dextranase/metabolismo , Glucosídeos/química , Glicosídeo Hidrolases/metabolismo , Espectroscopia de Ressonância Magnética , Peso Molecular , Ratos , beta-Amilase/metabolismo
9.
Biosci Biotechnol Biochem ; 70(12): 3013-8, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17151467

RESUMO

Production of a novel cyclomaltopentaose cyclized by an alpha-1,6-linkage, [ICG5; cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}], from starch was performed using isocyclomaltooligosaccharide glucanotransferase (IGTase) derived from Bacillus circulans AM7. The optimal conditions for ICG5-production from partially hydrolyzed starch were as follows: substrate concentration, 1.0% (w/v); pH, 5.5; temperature, 45 degrees C; reaction time, 24 h, IGTase, 1.0 unit/g-dry solid (DS); isoamylase, 2,500 units/g-DS. The yield of ICG5 reached 25.9% under optimal conditions. ICG5-production was achieved from partially hydrolyzed starch using a crude enzyme preparation containing IGTase. Finally, ICG5 was obtained in a yield of 17.9% (99.3% purity, 2,681 g-DS). A digestive test with a human salivary amylase, an artificial gastric juice, a pancreatic amylase, and small intestinal enzymes showed that ICG5 was an indigestible oligosaccharide.


Assuntos
Glucosiltransferases/metabolismo , Oligossacarídeos/síntese química , Amido/química , Bacillus/enzimologia , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Humanos , Concentração de Íons de Hidrogênio , Isoamilase/metabolismo , Cinética , Especificidade por Substrato , Temperatura
10.
Biosci Biotechnol Biochem ; 70(11): 2690-702, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17090949

RESUMO

The gene for a novel glucanotransferase, isocyclomaltooligosaccharide glucanotransferase (IgtY), involved in the synthesis of a cyclomaltopentaose cyclized by an alpha-1,6-linkage [ICG5; cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}] from starch, was cloned from the genome of B. circulans AM7. The IgtY gene, designated igtY, consisted of 2,985 bp encoding a signal peptide of 35 amino acids and a mature protein of 960 amino acids with a calculated molecular mass of 102,071 Da. The deduced amino-acid sequence showed similarities to 6-alpha-maltosyltransferase, alpha-amylase, and cyclomaltodextrin glucanotransferase. The four conserved regions common in the alpha-amylase family enzymes were also found in this enzyme, indicating that this enzyme should be assigned to this family. The DNA sequence of 8,325-bp analyzed in this study contained two open reading frames (ORFs) downstream of igtY. The first ORF, designated igtZ, formed a gene cluster, igtYZ. The amino-acid sequence deduced from igtZ exhibited no similarity to any proteins with known or unknown functions. IgtZ was expressed in Escherichia coli, and the enzyme was purified. The enzyme acted on maltooligosaccharides that have a degree of polymerization (DP) of 4 or more, amylose, and soluble starch to produce glucose and maltooligosaccharides up to DP5 by a hydrolysis reaction. The enzyme (IgtZ), which has a novel amino-acid sequence, should be assigned to alpha-amylase. It is notable that both IgtY and IgtZ have a tandem sequence similar to a carbohydrate-binding module belonging to a family 25. These two enzymes jointly acted on raw starch, and efficiently generated ICG5.


Assuntos
Bacillus/enzimologia , Expressão Gênica , Glucosiltransferases/química , Glucosiltransferases/metabolismo , alfa-Amilases/química , alfa-Amilases/metabolismo , Sequência de Aminoácidos , Bacillus/genética , Sequência de Bases , Clonagem Molecular , Sequência Conservada , Estabilidade Enzimática , Glucosiltransferases/genética , Concentração de Íons de Hidrogênio , Hidrólise , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Solubilidade , Amido/metabolismo , Temperatura , alfa-Amilases/genética
11.
J Nutr Sci Vitaminol (Tokyo) ; 52(3): 223-31, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16967768

RESUMO

Our previous study has shown that a soluble hesperidin derivative, glucosyl hesperidin (G-hesperidin), preferentially lowers serum triglyceride (TG) level in hypertriglyceridemic subjects through the improvement of very low-density lipoprotein (VLDL) metabolic abnormality. G-Hesperidin has also been found to decrease an elevated serum apolipoprotein B (apo B) level in the hypertriglyceridemic subjects, suggesting a possibility that this compound suppresses excess VLDL secretion in the liver. In the present study, to gain a better understanding of possible mechanisms by which G-hesperidin lowers serum TG, we examined whether this derivative affects apo B secretion from HepG2 human hepatoma cells, a model of hepatic VLDL secretion. As a result, G-hesperidin significantly reduced apo B secretion from the oleate-stimulated HepG2 cells. Furthermore, G-hesperidin significantly suppressed apo B secretion only in the oleate-stimulated cells and failed to act on the cells incubated without oleate. In the oleate-stimulated cells, G-hesperidin significantly decreased cellular cholesteryl ester (CE), although it had no effect on cellular TG or free cholesterol amounts. Moreover, the oleate-stimulated cells had a decrease in cellular apo B amounts by G-hesperidin exposure. These findings indicate that G-hesperidin down-regulates the assembly of apo B-containing lipoproteins via the reduction of CE synthesis augmented with oleate and results in suppressing excess apo B secretion from the cells. This effect is speculated to be associated with the improvement of VLDL metabolic abnormality in hypertriglyceridemic subjects and considered as a mechanism of lowering serum TG.


Assuntos
Apolipoproteínas B/metabolismo , Carcinoma Hepatocelular/metabolismo , Glucosídeos/farmacologia , Hesperidina/análogos & derivados , Neoplasias Hepáticas/metabolismo , Análise de Variância , Células Cultivadas , Ésteres do Colesterol/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Glucosídeos/química , Hesperidina/química , Hesperidina/farmacologia , Humanos , Técnicas In Vitro , Lipoproteínas VLDL/metabolismo , Modelos Biológicos , Fatores de Tempo , Triglicerídeos/metabolismo
12.
Biosci Biotechnol Biochem ; 70(8): 1954-60, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16926508

RESUMO

A novel glucanotransferase, involved in the synthesis of a cyclomaltopentaose cyclized by an alpha-1,6-linkage [ICG5; cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}], from starch, was purified to homogeneity from the culture supernatant of Bacillus circulans AM7. The pI was estimated to be 7.5. The molecular mass of the enzyme was estimated to be 184 kDa by gel filtration and 106 kDa by SDS-PAGE. These results suggest that the enzyme forms a dimer structure. It was most active at pH 4.5 to 8.0 at 50 degrees C, and stable from pH 4.5 to 9.0 at up to 35 degrees C. The addition of 1 mM Ca(2+) enhanced the thermal stability of the enzyme up to 40 degrees C. It acted on maltooligosaccharides that have degrees of polymerization of 3 or more, amylose, and soluble starch, to produce ICG5 by an intramolecular alpha-1,6-glycosyl transfer reaction. It also catalyzed the transfer of part of a linear oligosaccharide to another oligosaccharide by an intermolecular alpha-1,4-glycosyl transfer reaction. Thus the ICG5-forming enzyme was found to be a novel glucanotransferase. We propose isocyclomaltooligosaccharide glucanotransferase (IGTase) as the trivial name of this enzyme.


Assuntos
Bacillus/enzimologia , Glucosiltransferases/química , Oligossacarídeos/biossíntese , Sequência de Aminoácidos , Amilose/química , Ciclização , Dimerização , Glucanos/química , Glucosiltransferases/genética , Glucosiltransferases/isolamento & purificação , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Oligossacarídeos/química , Especificidade por Substrato , Temperatura , Fatores de Tempo
13.
Carbohydr Res ; 341(14): 2350-9, 2006 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-16872587

RESUMO

Chimeric phosphorylases were constructed of the kojibiose phosphorylase (KP) gene and the trehalose phosphorylase (TP) gene from Thermoanaerobacter brockii. Four chimeric enzymes had KP activity, and another had TP activity. Chimera V-III showed not TP, but KP activity, although only 125 amino acid residues in 785 residues of chimera V-III were from that of KP. Chimera V-III had 1% of the specific activity of the wild-type KP. Furthermore, the temperature profile and kinetic parameters of chimera V-III were remarkably changed as compared to those of the wild-type KP. The results of the molecular mass of chimera V-III using GPC (76,000 Da) strongly suggested that the chimera V-III protein exists as a monomer in solution, whereas wild-type KP and TP are hexamer and dimer structures, respectively. The result of the substrate specificity for phosphorolysis was that the chimera acted on nigerose, sophorose and laminaribiose, in addition to kojibiose. Furthermore, chimera V-III was also able to act on sophorose and laminaribiose in the absence of inorganic phosphate, and produced two trisaccharides, beta-D-glucosyl-(1-->6)-laminaribiose and laminaritriose, from laminaribiose.


Assuntos
Glucosiltransferases/química , Fosforilases/síntese química , Thermoanaerobacter/enzimologia , Sequência de Aminoácidos , Sequência de Bases , Domínio Catalítico , Dissacarídeos/química , Glucosiltransferases/genética , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Homologia de Sequência do Ácido Nucleico , Especificidade por Substrato , Trissacarídeos/isolamento & purificação
14.
J Biosci Bioeng ; 101(5): 385-90, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16781466

RESUMO

We investigated the acceptor specificity of a thermostable trehalose phosphorylase from Thermoanaerobacter brockii ATCC 35047 (TbTP) was examined using beta-D-glucose-1-phosphate (beta-G1P) as a glucosyl donor and oligosaccharides as the acceptor. Oligosaccharides with a reducing-end glucose residue as the C-6 substituent (e.g., isomaltose, gentiobiose, melibiose, isomaltotriose, and isopanose) were found to be successful acceptors. The transfer products of isomaltose, gentiobiose, and melibiose were isolated and characterized as 6-O-alpha-D-glucopyranosyl trehalose (alpha-GlcTre), 6-O-beta-D-glucopyranosyl trehalose (beta-GlcTre), and 6-O-alpha-D-galactopyranosyl trehalose (alpha-GalTre), respectively. To produce alpha-GalTre, a novel nonreducing trisaccharide, the reaction conditions of alpha-GalTre were examined using trehalose as a glucosyl donor. As a result, the yield of alpha-GalTre reached 40.5%.


Assuntos
Glucose/química , Glucofosfatos/química , Glucosiltransferases/química , Thermoanaerobacter/enzimologia , Trissacarídeos/química , Ativação Enzimática , Estabilidade Enzimática , Oxirredução , Especificidade por Substrato , Temperatura
15.
J Biosci Bioeng ; 101(5): 427-33, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16781473

RESUMO

The glucosyl transfer reaction of kojibiose phosphorylase (KP; EC 2.4.1.230) was examined using glycerol or myo-inositol as an acceptor. In the case of glycerol, KP produced two main transfer products: saccharides A and B. The structure of saccharide A was O-alpha-D-glucopyranosyl-(1-->1)-glycerol and that of saccharide B was O-alpha-D-glucopyranosyl-(1-->2)-O-alpha-D-glucopyranosyl-(1-->1)-glycerol. These results show that KP transferred a glucose residue to the hydroxyl group at position 1 of glycerol. On the other hand, when myo-inositol was used as an acceptor, KP produced four transfer products: saccharides 1-4. The structures of saccharides 1 and 2 were O-alpha-D-glucopyranosyl-(1-->1)- and O-alpha-D-glucopyranosyl-(1-->5)-myo-inositol, respectively; those of saccharides 3 and 4 were O-alpha-D-glucopyranosyl-(1-->2)-O-alpha-D-glucopyranosyl-(1-->1)- and O-alpha-D-glucopyranosyl-(1-->2)-O-alpha-D-glucopyranosyl-(1-->5)-myo-inositol, respectively. KP transferred a glucose residue to the hydroxyl group at position 1 or 5 of myo-inositol. On the basis of the structures of their glucosyl transfer products, glycerol and myo-inositol were found to have a common structure with three hydroxyl groups corresponding to the hydroxyl group of the glucose molecule at positions 2, 3 and 4. The conformation of these three hydroxyl groups in the structure is equatorial. This structure is the substrate recognition site of KP. It has been suggested that KP strictly recognizes the structures of glycerol and myo-inositol, and catalyzes the transfer reaction of a glucose residue to the hydroxyl group at position 1 in glycerol, and at position 1 or 5 in myo-inositol, corresponding to position 2 in glucose.


Assuntos
Dissacarídeos/química , Glicerol/química , Inositol/química , Thermoanaerobacter/enzimologia , Transporte de Elétrons , Ativação Enzimática , Glicosilação , Ligação Proteica
16.
Biosci Biotechnol Biochem ; 70(6): 1386-94, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16794318

RESUMO

Glucosyl hesperidin (G-hesperidin) is a water-soluble derivative of hesperidin. We compared the absorption and metabolism of G-hesperidin with those of hesperidin in rats. After oral administration of G-hesperidin or hesperidin to rats, hesperetin was detected in sera hydrolyzed with beta-glucuronidase, but it was not detectable in unhydrolyzed sera. Serum hesperetin was found more rapidly in rats administered G-hesperidin than in those administered hesperidin. The area under the concentration-time curve for hesperetin in the sera of rats administered G-hesperidin was approximately 3.7-fold greater than that of rats administered hesperidin. In the urine of both administration groups, hesperetin and its glucuronide were found. Urinary excretion of metabolites was higher in rats administered G-hesperidin than in those administered hesperidin. These results indicate that G-hesperidin presents the same metabolic profile as hesperidin. Moreover, it was concluded that G-hesperidin is absorbed more rapidly and efficiently than hesperidin, because of its high water solubility.


Assuntos
Glucosídeos/farmacocinética , Hesperidina/análogos & derivados , Administração Oral , Animais , Disponibilidade Biológica , Ceco/efeitos dos fármacos , Ceco/metabolismo , Cromatografia Líquida de Alta Pressão , Glucosídeos/administração & dosagem , Glucosídeos/sangue , Glucosídeos/urina , Ácido Glucurônico/sangue , Hesperidina/administração & dosagem , Hesperidina/sangue , Hesperidina/farmacocinética , Hesperidina/urina , Hidrólise , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Masculino , Estrutura Molecular , Ratos , Ratos Sprague-Dawley
17.
Carbohydr Res ; 341(8): 957-63, 2006 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-16545346

RESUMO

A bacterial strain AM7, isolated from soil and identified as Bacillus circulans, produced two kinds of novel cyclic oligosaccharides. The cyclic oligosaccharides were produced from amylose using a culture supernatant of the strain as the enzyme preparation. The major product was a cyclomaltopentaose cyclized by an alpha-(1-->6)-linkage, cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}. The other minor product was cyclomaltohexaose cyclized by an alpha-(1-->6)-linkage, cyclo-{-->6)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->4)-alpha-D-Glcp-(1-->}. We propose the names isocyclomaltopentaose (ICG5) and isocyclomaltohexaose (ICG6) for these novel cyclic maltooligosaccharides having one alpha-(1-->6)-linkage. ICG5 was digested by alpha-amylase derived from Aspergillus oryzae, cyclomaltodextrin glucanotransferase (CGTase) from Bacillus stearothermophilus, and maltogenic alpha-amylase. On the other hand, ICG6 was digested by CGTase from B. stearothermophilus and B. circulans, and maltogenic alpha-amylase. This is the first report of enzymatically produced cyclomaltopentaose and cyclomaltohexaose, which have an alpha-(1-->6)-linkage in their molecules.


Assuntos
Amilose/metabolismo , Bacillus/enzimologia , Ciclodextrinas/química , Ciclodextrinas/metabolismo , Geobacillus stearothermophilus/enzimologia , Oligossacarídeos/biossíntese , Aspergillus oryzae/enzimologia , Bacillus/classificação , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/metabolismo , Sequência de Carboidratos , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Meios de Cultura/farmacologia , Ciclização , Ciclodextrinas/isolamento & purificação , Glucosiltransferases/metabolismo , Glicosídeo Hidrolases/metabolismo , Peso Molecular , Ressonância Magnética Nuclear Biomolecular , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Espectrometria de Massas por Ionização por Electrospray , alfa-Amilases/metabolismo
18.
Appl Environ Microbiol ; 72(2): 1065-71, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16461650

RESUMO

A glycosyltransferase, involved in the synthesis of cyclic maltosylmaltose [CMM; cyclo-{-->6)-alpha-D-Glcp(1-->4)-alpha-D-Glcp(1-->6)-alpha-D-Glcp(1-->4)-alpha-D-Glcp(1-->}] from starch, was purified to homogeneity from the culture supernatant of Arthrobacter globiformis M6. The CMM-forming enzyme had a molecular mass of 71.7 kDa and a pI of 3.6. The enzyme was most active at pH 6.0 and 50 degrees C and was stable from pH 5.0 to 9.0 and up to 30 degrees C. The addition of 1 mM Ca2+ enhanced the thermal stability of the enzyme up to 45 degrees C. The enzyme acted on maltooligosaccharides that have degrees of polymerization of > or =3, amylose, and soluble starch to produce CMM but failed to act on cyclomaltodextrins, pullulan, and dextran. The mechanism for the synthesis of CMM from maltotetraose was determined as follows: (i) maltotetraose + maltotetraose --> 6(4)-O-alpha-maltosyl-maltotetraose + maltose and (ii) 6(4)-O-alpha-maltosyl-maltotetraose --> CMM + maltose. Thus, the CMM-forming enzyme was found to be a novel maltosyltransferase (6MT) catalyzing both intermolecular and intramolecular alpha-1,6-maltosyl transfer reactions. The gene for 6MT, designated cmmA, was isolated from a genomic library of A. globiformis M6. The cmmA gene consisted of 1,872 bp encoding a signal peptide of 40 amino acids and a mature protein of 583 amino acids with a calculated molecular mass of 64,637. The deduced amino acid sequence showed similarities to alpha-amylase and cyclomaltodextrin glucanotransferase. The four conserved regions common in the alpha-amylase family enzymes were also found in 6MT, indicating that 6MT should be assigned to this family.


Assuntos
Arthrobacter/enzimologia , Arthrobacter/genética , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Oligossacarídeos/biossíntese , Amido/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , DNA Bacteriano/genética , Estabilidade Enzimática , Genes Bacterianos , Glucosiltransferases/química , Concentração de Íons de Hidrogênio , Cinética , Modelos Biológicos , Dados de Sequência Molecular , Peso Molecular , Oligossacarídeos/química , Homologia de Sequência de Aminoácidos , Microbiologia do Solo , Especificidade por Substrato
19.
J Biosci Bioeng ; 100(2): 212-5, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16198267

RESUMO

Random mutation by error-prone PCR was introduced into kojibiose phosphorylase from Thermoanaerobacter brockii ATCC35047. One thermostable mutant enzyme, D513N, was isolated. The D513N mutant enzyme showed an optimum temperature of 67.5-70 degrees C (the wild type, 65 degrees C), and thermostability up to 67.5 degrees C (the wild type, up to 60 degrees C). The half-lives of D513N were estimated to be 135 h at 60 degrees C, 110 min at 70 degrees C and 6 min at 75 degrees C, respectively. They were about 1.6-fold, 7-fold and 6-fold longer than those of the wild-type enzyme, respectively.


Assuntos
Glucosiltransferases/metabolismo , Temperatura Alta , Thermoanaerobacter/enzimologia , Sequência de Bases , Primers do DNA , Estabilidade Enzimática , Glucosiltransferases/genética , Mutagênese , Reação em Cadeia da Polimerase
20.
J Biosci Bioeng ; 100(3): 343-6, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16243288

RESUMO

The kojibiose phosphorylase (KP) gene and trehalose phosphorylase (TP) gene from Thermoanaerobacter brockii ATCC35047 were intracellularly hyper-expressed under the control of the Bacillus amyloliquefaciens alpha-amylase promoter in Bacillus subtilis. The production yields were estimated to be 2.1 g of KP and 4.9 g of TP per liter of medium. Selaginose, non-reducing trisaccharide, was synthesized from trehalose utilizing the recombinant KP and TP from B. subtilis. Selaginose was not hydrolyzed by salivary amylase, artificial gastric juice, pancreatic amylase, or small intestinal enzymes.


Assuntos
Bacillus subtilis/metabolismo , Biotecnologia/métodos , Glucosiltransferases/genética , Fosforilases/genética , Thermoanaerobacter/enzimologia , Trissacarídeos/biossíntese , Bacillus subtilis/genética , Clonagem Molecular , Dissacarídeos/metabolismo , Expressão Gênica , Glucosiltransferases/metabolismo , Fosforilases/metabolismo , Thermoanaerobacter/genética
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