Search results for "Maltose"
showing 10 items of 41 documents
GH57 amylopullulanase from Desulfurococcus amylolyticus JCM 9188 can make highly branched cyclodextrin via its transglycosylation activity.
2018
Abstract Desulfurococcus amylolyticus is an anaerobic and hyperthermophilic crenarchaeon that can use various carbohydrates as energy sources. We found a gene encoding a glycoside hydrolase family 57 amylolytic enzymes (DApu) in a putative carbohydrate utilization gene cluster in the genome of D. amylolyticus . This gene has an open reading frame of 1,878 bp and consists of 626 amino acids with a molecular mass of 71 kDa. Recombinant DApu (rDApu) completely hydrolyzed pullulan to maltotriose by attacking α-1,6-glycosidic linkages, and was able to produce glucose and maltose from soluble starch and amylopectin. Although rDApu showed no activity toward α-cyclodextrin (CD) and β-CD, maltooctao…
Synthesis of Isomaltooligosaccharides by Saccharomyces cerevisiae Cells Expressing Aspergillus niger α‑Glucosidase
2017
The α-glucosidase encoded by the aglA gene of Aspergillus niger is a secreted enzyme belonging to family 31 of glycoside hydrolases. This enzyme has a retaining mechanism of action and displays transglycosylating activity that makes it amenable to be used for the synthesis of isomaltooligosaccharides (IMOs). We have expressed the aglA gene in Saccharomyces cerevisiae under control of a galactose-inducible promoter. Recombinant yeast cells expressing the aglA gene produced extracellular α-glucosidase activity about half of which appeared cell bound whereas the other half was released into the culture medium. With maltose as the substrate, panose is the main transglycosylation product after 8…
Bioprotection Can Be Tuned with Proper Protein/Saccharide Ratio: The Case of Solid Amorphous Matrices
2018
Saccharides, and in particular trehalose, are well known for their high efficiency in protecting biostructures against adverse environmental conditions. The protein dynamics is known to be highly inhibited in a low-water trehalose host medium, the inhibition being markedly dependent on the amount of residual water. Besides hydration, the protein/sugar ratio is expected to affect the properties of saccharide amorphous matrices. In this work, we report an infrared spectroscopy study in dry amorphous matrices of various sugars (the disaccharides trehalose, maltose, sucrose, and lactose, and the trisaccharide raffinose) containing myoglobin, at different protein/sugar ratios. We analyze the str…
An infrared spectroscopic tool for process monitoring: sugar contents during the production of a depilatory formulation.
2012
Abstract A fast, reliable and economical methodology has been developed to control the production process of sugar-based depilatories. The method is based on the use of attenuated total reflectance—Fourier transform infrared (ATR-FTIR) spectroscopy in combination with multivariate data analysis. A very simple sample preparation process involving the dissolution of samples in water was applied. Employing a multivariate calibration model established from data of 15 well characterized samples, prediction errors equal or below 3.04 mg mL−1 for the quantitative determination of fructose, glucose, sucrose, maltose and maltotriose were obtained. Results found in this preliminary study indicate a g…
Changes in myocardial iron content following administration of intravenous iron (Myocardial‐IRON): Study design
2018
Treatment with intravenous ferric carboxymaltose (FCM) has been shown to improve symptoms, functional capacity, and quality of life in patients with heart failure and iron deficiency. However, the underlying mechanisms for these beneficial effects remain undetermined. The aim of this study is to quantify cardiac magnetic resonance changes in myocardial iron content after administration of intravenous FCM in patients with heart failure and iron deficiency and contrast them with parameters of heart failure severity. This is a multicenter, double-blind, randomized study. Fifty patients with stable symptomatic heart failure, left ventricular ejection fraction <50%, and iron deficiency will be r…
Das durch das enzym amylomaltase eingestellte gleichgewicht oligomerer amylosen
1966
In der Reihe Glucose G, Maltose G2, Maltotriose G3 usw. stellt Amylomaltase die Gleichgewichte: 2 G2 = G3 + G (K1), G3 + G2 = G4 + G (K2) usw. ein. Die Gleichgewichtsgemische werden chromatographisch analysiert und daraus die Gleichgewichtskonstanten K1, K2 usw. berechnet. Diese steigen vom Wert K1 = 0,9 ab bis zu einem Grenzwert von etwa 1,05 asymptotisch an. Enthalpie, Entropie und freie Enthalpie liegen, auser fur den ersten Reaktionsschritt (K1), wie zu erwarten nahe bei 0. Das aus Escherichia coli (Stamm ML aus dem Institut Pasteur) isolierte Enzym Amylomaltase hat ein Molekulargewicht von etwa 130 000 und eine darauf bezogen Wechselahle von etwa 11 000 Mol Maltose pro Min. In the seri…
Chewing bread: impact on alpha-amylase secretion and oral digestion
2017
During chewing, saliva helps in preparing food bolus by agglomerating formed particles and initiates food enzymatic breakdown. However, limited information is actually available on the adaptation of saliva composition during oral processing of complex foods, especially for foods that are sensitive to salivary enzymes. We addressed this question in the context of starch–based products and salivary alpha-amylase. The objectives were two-fold: 1) determining if salivary alpha-amylase secretion can be modulated by bread type and 2) evaluating the contribution of the oral phase in bread enzymatic breakdown.Mouthfuls of three different wheat breads (industrial, artisan and whole breads) were chew…
Potential application of yeasts from Ecuadorian chichas in controlled beer and chicha production
2021
The potential of yeasts isolated from traditional chichas as starter cultures, either for controlled production of the native beverage or for industrial beer production, has been investigated. Three S. cerevisiae strains and one T. delbrueckii strain isolated from four different Ecuadorian chichas were compared to ale and lager beer strains with respect to fermentation performance, sugar utilisation, phenolic off-flavour production, flocculation and growth at low temperature. Fermentations were performed in 15 °P all-malt wort and in a model chicha substrate at 12 °C and 20 °C. Tall-tube fermentations (1.5 L) were also performed with both substrates to assess yeast performance and beer qual…
Short‐term changes in left and right systolic function following ferric carboxymaltose: a substudy of the Myocardial‐IRON trial
2020
Funding: This work was supported in part by an unrestricted grant from Vifor Pharma and Proyectos de Investigación de la Sección de Insuficiencia Cardiaca 2017 from Sociedad Española de Cardiología. The mechanisms underlying the beneficial effect of ferric carboxymaltose (FCM) in patients with heart failure (HF) and iron deficiency (ID) have not been completely characterized. The Myocardial-IRON trial was a double-blind, randomized trial that evaluated myocardial iron repletion following FCM vs. placebo in 53 patients with HF and ID. In this post hoc analysis, we evaluated whether treatment with FCM was associated with cardiac magnetic resonance changes in left and right ventricular functio…
Expression of Active Streptolysin O in Escherichia coli as a Maltose-Binding-Protein-Streptolysin-O Fusion Protein. The N-Terminal 70 Amino Acids are…
1996
Streptolysin 0 (SLO) is the prototype of a family of cytolysins that consists of proteins which bind to cholesterol and form very large transmembrane pores. Structure/function studies on the pore-forming cytolysin SLO have been complicated by the proteolytic inactivation of a substantial portion of recombinant SLO (rSLO) expressed in Escherichia coli. To overcome this problem, translational fusions between the E. coli maltose-binding protein (MBP) gene and SLO were constructed, using the vectors pMAL-p2 and pMAL-c2. MBP-SLO fusion proteins were degraded if secreted into the E. coli periplasm, but intact, soluble MBP-SLO fusion proteins were produced at high levels in the cytoplasm. Active S…