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1.
《Bioscience, biotechnology, and biochemistry》2013,77(10):2086-2090
The regioselectivity of β-galactosidase derived from Bacillus circulans ATCC 31382 (β-1,3-galactosidase) in transgalactosylation reactions using D-mannose as an acceptor was investigated. This D-mannose associated regioselectivity was found to be different from reactions using either GlcNAc or GalNAc as acceptors, not only for β-1,3-galactosidase but also for β-galactosidases of different origins. The relative hydrolysis rate of Galβ-pNP and D-galactosyl-D-mannoses, of various linkages, was also measured in the presence of β-1,3-galactosidase and was found to correlate well with the ratio of disaccharides formed by transglycosylation. The unexpected regioselectivity using D-mannose can therefore be explained by an anomalous specificity in the hydrolysis reaction. By utilizing the identified characteristics of both regioselectivity and hydrolysis specificity using D-mannose, an efficient method for enzymatic synthesis of β-1,3-, β-1,4- and β-1,6-linked D-galactosyl-D-mannose was subsequently established. 相似文献
2.
《Bioscience, biotechnology, and biochemistry》2013,77(9):1974-1977
D-Galactosyl-α-1,3-D-galactopyranose (1) was chemically prepared in a good yield by coupling phenyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-galactopyranoside (5) or 2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl bromide (8) with 1,2:5,6-di-O-cyclohexylidene-α-D-galactofuranose (3) with subsequent de-O-benzylation and de-O-cyclohexylidenation of the resulting protected α-1,3-disaccharide. 相似文献
3.
《Bioscience, biotechnology, and biochemistry》2013,77(10):2130-2132
The synthesis is reported of β-D-fructopyranosyl-(2→6)-D-glucopyranose that had previously been isolated from a fermented plant extract as a new saccharide. A disaccharide was predominately formed from an equal amount of D-glucose and D-fructose under melting conditions at 140 °C for 60 to 90 min. This saccharide was isolated from the reaction mixture by carbon-Celite column chromatography and preparative HPLC, and was confirmed to be β-D-fructopyranosyl-(2→6)-D-glucopyranose by TOF-MS and NMR analyses. 相似文献
4.
Substrate Specificity of Thermostable D-Alanine-D-alanine ligase from Thermotoga maritima ATCC 43589
《Bioscience, biotechnology, and biochemistry》2013,77(11):2790-2792
D-Alanine-D-alanine ligase (Ddl) and its mutants maintain the biosynthesis of peptidoglycan, and the substrate specificity of Ddls partially affects the resistance mechanism of vancomycin-resistant enterococci. Through investigation of Ddls, Ddl from Thermotoga maritima ATCC 43589 showed novel characteristics, vis. thermostability up to 90 °C and broad substrate specificity toward 15 D-amino acids, particularly D-alanine, D-cysteine, and D-serine, in that order. 相似文献
5.
《Bioscience, biotechnology, and biochemistry》2013,77(5):942-946
We investigated in this study the effect of modified arabinoxylan from rice bran (MGN-3) and its fractions on D-galactosamine (D-GalN)-induced IL-18 expression and hepatitis in rats. Male Wistar rats were pretreated with MGN-3 or fractions of the MGN-3 hydrolysate, or with saline 1 h before administering D-GalN (400 mg/kg B.W.). The serum transaminase activities, IL-18 mRNA expression level in the liver and IL-18 concentration in the serum were determined 24 h after injecting D-GalN. Both the oral and intraperitoneal administration of MGN-3 (20 mg/kg B.W.) alleviated D-GalN-induced hepatic injury under these experimental conditions. The low-molecular-weight fraction (LMW) of MGN-3 showed the strongest protective effect on D-GalN-induced liver injury, its main sugar component being glucose. Moreover, the D-GalN-induced IL-18 expression was significantly reduced by treating with MGN-3 and LMW. The results suggest that MGN-3 and LMW could provide significant protection against D-GalN liver injury, and that IL-18 might be involved in their protective influence. 相似文献
6.
《Bioscience, biotechnology, and biochemistry》2013,77(2):538-541
A putative endo-β-1,4-D-galactanase gene of Thermotoga maritima was cloned and overexpressed in Escherichia coli. The recombinant enzyme hydrolyzed pectic galactans and produced D-galactose, β-1,4-D-galactobiose, β-1,4-D-galactotriose, and β-1,4-D-galactotetraose. The enzyme displayed optimum activity at 90 °C and pH 7.0. It was slowly inactivated above pH 8.0 and below pH 5.0 and stable at temperatures up to 80 °C. 相似文献
7.
《Bioscience, biotechnology, and biochemistry》2013,77(4):700-704
Depsipeptides are peptide-like polymers consisting of amino acids and hydroxy acids, and are expected to be new functional materials for drug-delivery systems and polymer science. In our previous study, D-alanyl-D-lactate, a type of depsipeptide, was enzymatically synthesized using D-alanine-D-alanine ligase from Thermotoga maritima ATCC 43589 (TmDdl) by Y207F substitution. Thereafter, in this study, further mutagenesis was introduced, based on structural comparison between TmDdl and a well-characterized D-alanine-D-alanine ligase from Escherichia coli. The S137A/Y207F mutant showed higher D-alanyl-D-lactate and lower D-alanyl-D-alanine synthesizing activity than the Y207F mutant. This suggests that substitution at the S137 residue contributes to product selectivity. Saturated mutagenesis on S137 revealed that the S137G/Y207F mutant showed the highest D-alanyl-D-lactate synthesizing activity. Moreover, the mutant showed broad substrate specificity toward D-amino acid and recognized D-lactate and D,L-isoserine as substrates. On the basis of these characteristics, various depsipeptides can be produced using S137G/Y207F-replaced TmDdl. 相似文献
8.
《Bioscience, biotechnology, and biochemistry》2013,77(11):2314-2322
The D-sorbitol dehydrogenase gene, sldA, and an upstream gene, sldB, encoding a hydrophobic polypeptide, SldB, of Gluconobacter suboxydans IFO 3255 were disrupted in a check of their biological functions. The bacterial cells with the sldA gene disrupted did not produce L-sorbose by oxidation of D-sorbitol in resting-cell reactions at pHs 4.5 and 7.0, indicating that the dehydrogenase was the main D-sorbitol-oxidizing enzyme in this bacterium. The cells did not produce D-fructose from D-mannitol or dihydroxyacetone from glycerol. The disruption of the sldB gene resulted in undetectable oxidation of D-sorbitol, D-mannitol, or glycerol, although the cells produced the dehydrogenase. The cells with the sldB gene disrupted produced more of what might be signal-unprocessed SldA than the wild-type cells did. SldB may be a chaperone-like component that assists signal processing and folding of the SldA polypeptide to form active D-sorbitol dehydrogenase. 相似文献
9.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1652-1655
D-Galactosyl-β1→4-L-rhamnose (GalRha) was produced enzymatically from 1.1 M sucrose and 1.0 M L-rhamnose by the concomitant actions of four enzymes (sucrose phosphorylase, UDP-glucose-hexose 1-phosphate uridylyltransferase, UDP-glucose 4-epimerase, and D-galactosyl-β1→4-L-rhamnose phosphorylase) in the presence of 1.0 mM UDP-glucose and 30 mM inorganic phosphate. The accumulation of GalRha in 1 liter of the reaction mixture reached 230 g (the reaction yield was 71% from L-rhamnose). Sucrose and fructose in the reaction mixture were removed by yeast treatment, but isolation of GalRha by crystallization after yeast treatment was unsuccessful. Finally, 49 g of GalRha was isolated from part of the reaction mixture with yeast treatment by gel-filtration chromatography. 相似文献
10.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2011-2014
The synthesis of glucooligosaccharides from α-D-glucose-1-phosphate by transglucosylation with sucrose phosphorylase from Leuconostoc mesenteroides was studied using the purified enzyme and high performance liquid chromatography. The enzyme had a rather broad acceptor specificity and transferred glucosyl residues to various acceptors such as sugars and sugar alcohols. Especially, 5-carbon sugar alcohols (pentitols), D- and L-arabitol were acceptors equal to D-fructose, which was known as a good acceptor. The transfer product of xylitol formed by the enzyme was investigated. The structure of the product was found to be 4-O-α-D-glucopyranosyl-xylitol (G-X) by acid hydrolysis and 13C-nuclear magnetic resonance analysis. G-X is a probable candidate for a preventive for dental caries because it reduced the synthesis of water-insoluble glucan by Streptococcus mutans and kept a neutral pH in the cell suspension. 相似文献
11.
Tyrosol β-d-fructofuranoside and hydroxytyrosol β-d-fructofuranoside have been synthesized as new compounds in 27.6 and 19.5% respective yields through transfructosylation of tyrosol and hydroxytyrosol. Yeast β-galactosidase Lactozym 3000?L comprising invertase activity was used as catalyst. Besides the main monofructosides, an equimolar mixture of tyrosol β-d-fructofuranosyl-((2→1)-β-d-fructofuranoside and tyrosol β-d-fructofuranosyl-(2→6)-β-d-fructofuranoside was isolated as additional product fraction in 14.3% yield. 相似文献
12.
《Bioscience, biotechnology, and biochemistry》2013,77(10):1565-1569
The surface lipids of Nicotiana benthamiana contained novel glycerolipids and several varieties of glycolipids. As glycerolipids, the triacylglycerol, 1,3-diacylglycerol, and 1,2-diacylglycerol types of glycerolipids were isolated and identified. Each lipid contained acetyl, 16–methylheptadecanoyl, and 18–methylnonadecanoyl moieties. The acetylated position of each lipid was determined by 2D-NMR, using the HMBC technique. The structures were 1,3-di-O-acetyl-2-O-acylglycerol, 1-O-acetyl-3-O-acylglycerol, and 1-O-acetyl-2-O-acylglycerol. As glycolipids, one glucose ester and four types of sucrose esters were isolated and identified. These glycolipids contained acetic acid and such branched short-chain fatty acids as 5-methylhexanoic, 4-methylhexanoic, 6-methylheptanoic, and 5-methylheptanoic acids. The structure of the glucose ester was 3,4-di-O-acyl-α-D-glucopyranose. The structures of the sucrose esters were 6-O-acetyl-4-O-acyl-α-D-glucopyranosyl-(3-O-acyl)-β-D-fructofuranoside, 4-O-acyl-α-D-glucopyranosyl-(3-O-acyl)-β-D-fructofuranoside, 3,4-di-O-acyl-α-D-glucopyranosyl-β-D-fructofuranoside, and 6-O-acetyl-α-D-glucopyranosyl-β-D-fructofuranoside. 相似文献
13.
《Bioscience, biotechnology, and biochemistry》2013,77(11):1815-1819
Two new alcoholic aroma precursors, cis- and trans-linalool 3,7-oxides 6-O-β-D-apiofuranosyl-β-D-glucopyranosides (1 and 2), as well as two already known compounds, (Z)-3-hexenyl β-D-glucopyranoside (3) and methyl salicylate 6-O-β-D-xylopyranosyl-β-D-glucopyranoside (β-primeveroside: 4), and another new monoterpendiol glycoside, 8-hydroxygeranyl β-primeveroside (5) have recently been isolated as aroma precursors in tea leaves (Camellia sinensis var. sinensis cv. Maoxie) ready for oolong tea processing. 相似文献
14.
Yuji Terami Keiko Uechi Saki Nomura Naoki Okamoto Kenji Morimoto 《Bioscience, biotechnology, and biochemistry》2013,77(10):1725-1729
l-ribose isomerase (L-RI) from Cellulomonas parahominis MB426 can convert l-psicose and d-tagatose to l-allose and d-talose, respectively. Partially purified recombinant L-RI from Escherichia coli JM109 was immobilized on DIAION HPA25L resin and then utilized to produce l-allose and d-talose. Conversion reaction was performed with the reaction mixture containing 10% l-psicose or d-tagatose and immobilized L-RI at 40 °C. At equilibrium state, the yield of l-allose and d-talose was 35.0% and 13.0%, respectively. Immobilized enzyme could convert l-psicose to l-allose without remarkable decrease in the enzyme activity over 7 times use and d-tagatose to d-talose over 37 times use. After separation and concentration, the mixture solution of l-allose and d-talose was concentrated up to 70% and crystallized by keeping at 4 °C. l-Allose and d-talose crystals were collected from the syrup by filtration. The final yield was 23.0% l-allose and 7.30% d-talose that were obtained from l-psicose and d-tagatose, respectively. 相似文献
15.
《Bioscience, biotechnology, and biochemistry》2013,77(5):1006-1009
The L-rhamnose isomerase gene (rhi) of Mesorhizobium loti was cloned and expressed in Escherichia coli, and then characterized. The enzyme exhibited activity with respect to various aldoses, including D-allose and L-talose. Application of it in L-talose production from galactitol was achieved by a two-step reaction, indicating that it can be utilized in the large-scale production of L-talose. 相似文献
16.
《Bioscience, biotechnology, and biochemistry》2013,77(10):1730-1735
L-Tartrate in wines and grapes was enzymatically quantified by using the secondary activity of D-malate dehydrogenase (D-MDH). NADH formed by the D-MDH reaction was monitored spectrophotometrically. Under the optimal conditions, L-tartrate (a 1.0 mM sample solution) was fully oxidized by D-MDH in 30 min. A linear relationship was obtained between the absorbance difference and the L-tartrate concentration in the range of a 0.02-1.0 mM sample solution with a correlation coefficient of 0.9991. The relative standard deviation from ten measurements was 1.71% at the 1.0 mM sample solution level. The proposed method was compared with HPLC, and the values determined by both methods were in good agreement. 相似文献
17.
《Bioscience, biotechnology, and biochemistry》2013,77(8):2010-2012
The transesterification of D-allose (the C-3 epimer of D-glucose) with vinyl octanoate using Candida antarctica lipase in tetrahydrofuran proceeded with high regioselectivity to produce 6-O-octanoyl-D-allose with nearly complete conversion. The growth-inhibiting activity of 6-O-octanoyl-D-allose on lettuce seedlings was about 6-fold greater than that of D-allose. 相似文献
18.
Emiko Matsunaga Yujiro Higuchi Kazuki Mori Nao Yairo Saki Toyota Takuji Oka 《Bioscience, biotechnology, and biochemistry》2017,81(7):1314-1319
As a constituent of polysaccharides and glycoconjugates, β-d-galactofuranose (Galf) exists in several pathogenic microorganisms. Although we recently identified a β-d-galactofuranosidase (Galf-ase) gene, ORF1110, in the Streptomyces strain JHA19, very little is known about the Galf-ase gene. Here, we characterized a strain, named JHA26, in the culture supernatant of which exhibited Galf-ase activity for 4-nitrophenyl β-d-galactofuranoside (pNP-β-d-Galf) as a substrate. Draft genome sequencing of the JHA26 strain revealed a putative gene, termed ORF0643, that encodes Galf-ase containing a PA14 domain, which is thought to function in substrate recognition. The recombinant protein expressed in Escherichia coli showed the Galf-specific Galf-ase activity and also released galactose residue of the polysaccharide galactomannan prepared from Aspergillus fumigatus, suggesting that this enzyme is an exo-type Galf-ase. BLAST searches using the amino acid sequences of ORF0643 and ORF1110 Galf-ases revealed two types of Galf-ases in Actinobacteria, suggesting that Galf-specific Galf-ases may exhibit discrete substrate specificities. 相似文献
19.
Wataru Saburi 《Bioscience, biotechnology, and biochemistry》2016,80(7):1294-1305
Carbohydrate isomerases/epimerases are essential in carbohydrate metabolism, and have great potential in industrial carbohydrate conversion. Cellobiose 2-epimerase (CE) reversibly epimerizes the reducing end d-glucose residue of β-(1→4)-linked disaccharides to d-mannose residue. CE shares catalytic machinery with monosaccharide isomerases and epimerases having an (α/α)6-barrel catalytic domain. Two histidine residues act as general acid and base catalysts in the proton abstraction and addition mechanism. β-Mannoside hydrolase and 4-O-β-d-mannosyl-d-glucose phosphorylase (MGP) were found as neighboring genes of CE, meaning that CE is involved in β-mannan metabolism, where it epimerizes β-d-mannopyranosyl-(1→4)-d-mannose to β-d-mannopyranosyl-(1→4)-d-glucose for further phosphorolysis. MGPs form glycoside hydrolase family 130 (GH130) together with other β-mannoside phosphorylases and hydrolases. Structural analysis of GH130 enzymes revealed an unusual catalytic mechanism involving a proton relay and the molecular basis for substrate and reaction specificities. Epilactose, efficiently produced from lactose using CE, has superior physiological functions as a prebiotic oligosaccharide. 相似文献
20.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1374-1375
D-Ins(1,3,4,5)P4 and unnatural L-Ins(1,3,4,5)P4 were prepared in gram-quantities from D- and L-2,6-di-O-benzyl-myo-inositol by a chemical phosphorylation and deprotection step in high yield and purity without extensive purification. The optically pure benzyl derivatives were obtained by enzyme-catalyzed resolution of racemic 2,6-di-O-benzyl-myo-inositol under acyl-transfer conditions in vinyl acetate as the acyl donor. The lipase of Candida antarctica only acetylated regio- and enantio-selectively the L-enantiomer, providing exclusively L-5-acetyl-2,6-di-O-benzyl-myo-inositol, whereas the D-enantiomer remained unchanged. 相似文献