Showing papers on "Melibiose published in 2008"
TL;DR: Two strains, Lactobacillus curvatus R08 and Leuconostoc mesenteroides [corrected]JK55, showed the highest levels of raffinose degrading activity at over 40 U mL(-1), and presented maximum activities during the stationary phase in a medium where raff inose was the only carbon source, providing the optimum conditions to induce alpha-Gal from these strains.
58 citations
TL;DR: The Acetobacter and Gluconobacter strains isolated in this study were found to be responsible for the spoilage of mnazi.
Abstract: This study investigated the occurrence and identified the dominant spoilage genera of acetic acid bacteria in coconut wine (mnazi), by plating the dilution series previously pre-enriched in a basal medium onto GYP agar, followed by physiological and biochemical tests. Both Acetobacter and Gluconobacter strains were Gram variable, oxidase negative and catalase positive. All Acetobacter strains over-oxidized ethanol to acetic acid and finally to CO2 and H2O, while Gluconobacter were unable to oxidize acetic acid to CO2 and H2O. Acetobacter and Gluconobacter alike showed positive growth at 25, 30 and 40°C and also at pH 7.0 and 4.5, while there was no growth at 45°C, pH 2.5 and 8.5. Acetobacter strains oxidized both lactate and acetate while Gluconobacter oxidized lactate only. Both genera were unable to liquefy gelatin. Acetobacter showed negative growth at 15°C and also in peptone medium, while Gluconobacter showed positive growth both in peptone medium and at 15°C. Both genera were able to ferment arabinose, xylose, ribose, glucose, galactose, mannose and melibiose and unable to ferment amylagdine, cellibiose, esculine, lactose, maltose, mannitol, melezitose, Nagluconate, raffinose, rhamnose and salicine. The Acetobacter and Gluconobacter strains isolated in this study were found to be responsible for the spoilage of mnazi.
55 citations
TL;DR: The results indicate that different cultivars of soybean produce lectins that are not identical in every aspect, and melibiose most potently inhibited the hemagglutinating activity of the lectin.
Abstract: A dimeric 50 kDa melibiose-binding lectin was isolated from the seeds of the cultivar of soybean (Glycine max), called the small glossy black soybean. The isolation procedure comprised ion exchange chromatography on Q Sepharose, SP Sepharose and Mono Q followed by gel filtration on Superdex 75. The lectin was adsorbed on all three ion exchangers, and it exhibited an N-terminal sequence identical to that of soybean lectin. Of all the sugars tested, melibiose most potently inhibited the hemagglutinating activity of the lectin, which was stable between pH 3-12 and 0-70 degrees C. The lectin evoked maximal mitogenic response at about the same molar concentration as Con A. However, the response was much weaker. The soybean lectin inhibited the activity of HIV-1 reverse transcriptase as well as the proliferation of breast cancer MCF7 cells and hepatoma HepG2 cells with an IC50 of 2.82 microM, 2.6 microM and 4.1 microM, respectively. There was no antifungal activity. Another lectin was isolated from a different cultivar of soybean called little black soybean. The lectin was essentially similar to small glossy black soybean lectin except for a larger subunit molecular mass (31 kDa), a more potent mitogenic activity and lower thermostability. The results indicate that different cultivars of soybean produce lectins that are not identical in every aspect.
55 citations
TL;DR: A novel alpha-galactosidase gene (aga2) was cloned from Bifidobacterium breve 203 and was capable of catalyzing transglycosylation as well as hydrolysis and catalyzing glycosyl transfer to various acceptors including monosaccharides, disaccharide and sugar alcohols.
Abstract: A novel α-galactosidase gene (aga2) was cloned from Bifidobacterium breve 203. It contained an ORF of 2226-bp nucleotides encoding 741 amino acids with a calculated molecular mass of 81.5 kDa. The recombinant enzyme Aga2 was heterogeneously expressed, purified and characterized. Regarding substrate specificity for hydrolysis, Aga2 was highly active towards p-nitrophenyl-α-d-galactopyranoside (pNPG). The Km value for pNPG was estimated to be 0.27 mM and for melibiose it was estimated to be 4.3 mM. Aga2 was capable of catalyzing transglycosylation as well as hydrolysis. The enzyme synthesized a trisaccharide (Gal-α-1, 4-Gal-α-1, 6-Glc) using melibiose as a substrate. It was a new oligosaccharide produced by glycosidase and contained Gal-α-1,4 linkage, a novel galactosidic link formed by microbial α-galactosidase. In the presence of pNPG as a donor, Aga2 was able to catalyze glycosyl transfer to various acceptors including monosaccharides, disaccharides and sugar alcohols.
50 citations
TL;DR: Partial primary structure analysis of 7 peptides by cleavage with lysyl endopeptidase indicated that one of the peptides showed significant similarity with galectin purified from the sponge Geodia cydonium.
Abstract: A lectin recognizing both Galβ1-3GlcNAc and Galβ1-4GlcNAc was purified from the demosponge Halichondria okadai by lactosyl-agarose affinity chromatography. The molecular mass of the lectin was determined to be 30 kDa by SDS-PAGE under reducing and non-reducing conditions and 60 kDa by gel permeation chromatography. The p I value of the lectin was 6.7. It was found to agglutinate trypsinized and glutaraldehyde-fixed rabbit and human erythrocytes in the presence and absence of divalent cations. The hemagglutinating activity by the lectin was inhibited by d -galactose, methyl- d -galactopyranoside, N -acetyl- d -galactosamine, methyl- N -acetyl- d -galactosaminide, lactose, melibiose, and asialofetuin. The K d of the lectin against p -nitrophenyl-β-lactoside was determined to be 2.76 × 10 − 5 M and its glycan-binding profile given by frontal affinity chromatography was shown to be similar to many other known galectins. Partial primary structure analysis of 7 peptides by cleavage with lysyl endopeptidase indicated that one of the peptides showed significant similarity with galectin purified from the sponge Geodia cydonium .
48 citations
TL;DR: The alpha-galactosidase purified from germinating seeds had an M(r) of 38,000 and maximal activity at pH 5.0-5.5 and 50 degrees C, and in addition to its ability to hydrolyze raffinose and stachyose, the enzyme also hydrolyzed galactomannan.
29 citations
TL;DR: Stage-specific analyses of starch and 18 sugars made throughout seed development for zygotic embryo and female gametophyte tissues of loblolly pine suggest stage-specific media composition for each step in the somatic embryogenesis protocol.
Abstract: Stage-specific analyses of starch and 18 sugars, including pentoses, hexoses, disaccharides, trisaccharides, oligosaccharides and sugar alcohols, were made throughout seed development for zygotic embryo and female gametophyte (FG) tissues of loblolly pine (Pinus taeda L.). Tissue was most often analyzed in triplicate from two open-pollinated families grown in different locations and sampled in different years. Carbohydrates were analyzed by enzymatic assay, high performance liquid chromatography or gas chromatography/mass spectrometry. For all carbohydrates quantified, peak concentrations were higher in embryo tissue than in FG tissue. Significant changes in starch and sugar concentrations occurred over time, with both seed collections showing similar trends in temporal changes. Although concentrations were not always similar, embryo and FG tissues generally showed similar patterns of change in starch and sugar concentrations over time. Total starch concentration was highest during early seed development and decreased as development progressed. The major sugars contributing to osmotic potential during early seed development were D-pinitol, sucrose, fructose and glucose. During mid-seed development, D-pinitol, sucrose, fructose, glucose, melibiose and raffinose provided major contributions to the osmotic environment. During late seed development, sucrose, raffinose, melibiose, stachyose and fructose were the major contributors to osmotic potential. These data suggest stage-specific media composition for each step in the somatic embryogenesis protocol.
29 citations
TL;DR: Analysis of infrared polarized absorbance spectra and linear dichroism spectra of reconstituted melibiose permease from Escherichia coli shows that the oriented structures correspond mainly to tilted transmembrane alpha-helices, forming an average angle of approximately 26 degrees with the membrane normal in substrate-free medium.
24 citations
TL;DR: It is shown that MelY binds TMG and conserves Cys148 (helix V) as a TMG binding residue but fails to transport this ligand, and that Val367, at the periplasmic end of transmembrane helix XI, contributes in defining the substrate selectivity profile.
10 citations
TL;DR: The objective of this work is to develop the Pichia system to produce a large quantity of enzyme for blood cell conversion for transfusion by determining the Michelis constant (Km) of the enzyme for melibiose, raffinose, and stachyose, which showed thatMelibiose was hydrolyzed faster than raff inose, whereas the published data reported a reversed sequence, r Affinose >melibiose.
Abstract: We have successfully cloned an α-galactosidase gene from a rice cDNA library and transformed it into Escherichia coli BL21. It was subsequently cloned to the pPIC9K vector and expressed in Pichia pastoris. A selected clone was found to result in high production yield of the galactosidase enzyme. The secreted enzyme was purified, and it revealed as a major protein band on an SDS-PAGE gel. The optimal pH value, enzyme stabilities, and substrate specificity were studied. The enzyme specificity toward the terminal α1→6, 1→4, and 1→3 linked galactosyl residue from various substrates was investigated. By determining the Michelis constant (Km) of the enzyme for melibiose, raffinose, and stachyose, our results showed that melibiose was hydrolyzed faster than raffinose, whereas the published data reported a reversed sequence, raffinose > melibiose. The enzyme also showed the ability of converting B red blood cells into O red cells. The objective of this work is to develop the Pichia system to produce a large quantity of enzyme for blood cell conversion for transfusion.
6 citations
TL;DR: The objective of the present study was to describe in detail the biliary pharmacokinetics of melibiose and rhamnose in rats and evaluate the changes of both sugars' pharmacokinetic upon impairment of the blood–biliary barrier by acute extrahepatic cholestasis in rats.
Abstract: Background and Aim: Melibiose/rhamnose permeability test is used for noninvasive intestinal mucosa barrier testing. However, the possible escape route of the absorbed saccharides through either intact or impaired blood–biliary barriers has not so far been explored. The objective of the present study was therefore two-fold: First, to describe in detail the biliary pharmacokinetics of melibiose and rhamnose in rats; second, to evaluate the changes of both sugars' pharmacokinetics upon impairment of the blood–biliary barrier by acute extrahepatic cholestasis in rats.
Methods: Bile duct obstructed (BDO), sham-operated and intact (unoperated) male Wistar rats were administered, 24 h after the appropriate intervention, with a single intravenous dose of melibiose and rhamnose, and a 4-h pharmacokinetic study was performed.
Results: In intact animals, the biliary excretion of melibiose and rhamnose was only 0.06% and 0.4% of the administered dose, respectively, while the urinary excretion accounted for 70.6% and 61.7%, respectively. In BDO animals, the biliary excretion rate of both saccharides, especially that of melibiose, was increased with a consequent 4.4-fold rise of the biliary melibiose/rhamnose ratio, the accepted paracellular permeability indicator. Both, the renal clearance of melibiose and the urinary melibiose/rhamnose ratio remained uninfluenced by cholestasis.
Conclusion: The present study is the first to describe in detail pharmacokinetic parameters and the biliary excretion of melibiose and rhamnose in healthy and cholestatic rats. The altered melibiose/rhamnose biliary excretion ratio in BDO rats indicates that the test is able to detect the impairment of the blood–biliary barrier in acute extrahepatic cholestasis.
Patent•
17 Mar 2008
TL;DR: The medium for cell culture comprises lactulose and at least one succharide selected from a group comprising raffinose, lactose, melibiose, palatinose, trehalose, Xylose, isomaltose, maltotriose, N-acetylglucosamine, xylitol, inositol, mannitol, sorbitol, maltitol, galactose, turanose and lactitol.
Abstract: PROBLEM TO BE SOLVED: To provide a culture medium for production of desired protein or proliferation of desired virus by using an animal cell, and a method for producing protein and a method for promoting proliferation of virus using these culture media.SOLUTION: There is disclosed a cell culture medium at least comprising lactulose. The medium for cell culture comprises lactulose and at least one succharide selected from a group comprising raffinose, lactose, melibiose, palatinose, trehalose, xylose, isomaltose, maltotriose, N-acetylglucosamine, xylitol, inositol, mannitol, sorbitol, maltitol, galactose, turanose and lactitol in addition to the lactulose.
Journal Article•
TL;DR: α-Galactosidase gene from Leuconostoc mesenteroides SY1 was expressed in a heterologous host, Lactobacillus brevis 2.14 and produced much more α-Gal when grown on melibiose than on glucose, sucrose, and fructose.
Abstract: α-Galactosidase gene (aga) from Leuconostoc mesenteroides SY1 was expressed in a heterologous host, Lactobacillus brevis 2.14 using an Escherichia coli-Leuconostoc shuttle vector, pSJE. pSJEaga (pSJE carrying aga) was introduced into Lactobacillus brevis 2.14 by electroporation and transformation efficiency was 1.1×10 3 per μg DNA. L. brevis transformants (TFs) showed higher α-galactosidase (α-Gal) activities than cells containing pSJE. Transcription levels of aga in L. brevis 2.14 grown on different carbon sources (1%, w/v) were examined by slot blot analysis. Aga transcript levels and α-Gal activities were higher in cells grown on melibiose, raffinose, and galactose than cells on glucose, sucrose, and fructose. Western blot result showed that L. brevis 2.14 harboring pSJEaga produced much more α-Gal when grown on melibiose than on glucose.
TL;DR: The soy meal waste extract can be recommended as a suitable medium for the industrial cultivation of strains producing α-galactosidase for food and fodder purposes.
Abstract: Soy meal extract presenting a waste product from soy protein concentrate manufacture was applied as cultivation medium for the production of extracellular α-galactosidase in submerged fermentation of the filamentous fungus Humicola lutea 120–5. Maximum enzyme activity (2000 U.l−1) was produced when the soy meal extract containing 5% dry substances (∼1% raffinose oligosaccharides) was used at 120th h cultivation and 35°C. Chromatography on Sephadex G-100 and DEAE-cellulose resulted in a purified α-galactosidase fraction with specific enzyme activity of 37 U.mg−1. The optimum conditions for the enzyme reaction were pH 4.0 to 4.5 at 50°C. The partially purified enzyme was stable up to 40°C at pH 2.0 to 7.5. The crude enzyme preparation readily hydrolyzes raffinose according HPLC analysis, but no activity against disaccharides as sucrose and melibiose was observed. The soy meal waste extract can be recommended as a suitable medium for the industrial cultivation of strains producing α-galactosidase for...
Patent•
06 Mar 2008
TL;DR: In this article, a method for producing melibiose from glucose and galactose as raw materials is provided, involving using α-galactosidase derived from a strain belonging to Bacillus coagulans.
Abstract: PROBLEM TO BE SOLVED: To provide a method for producing melibiose selectively from glucose and galactose as inexpensive raw materials. SOLUTION: The method for producing melibiose from glucose and galactose as raw materials is provided, involving using α-galactosidase derived from a strain belonging to Bacillus coagulans and capable of selectively synthesizing melibiose. COPYRIGHT: (C)2009,JPO&INPIT