Changes In Saccharides Research Articles

In Silico Study on a Binding Mechanism of ssDNA Aptamers Targeting Glycosidic Bond-Containing Small Molecules.

Aptamer-based detection targeting glycoconjugates has attracted significant attention for its remarkable potential in identifying structural changes in saccharides in different stages of various diseases. However, the challenges in screening aptamers for small carbohydrates or glycoconjugates, which contain highly flexible and diverse glycosidic bonds, have hindered their application and commercialization. In this study, we investigated the binding conformations between three glycosidic bond-containing small molecules (GlySMs; glucose, N-acetylneuraminic acid, and neomycin) and their corresponding aptamers in silico, and analyzed factors contributing to their binding affinities. Based on the findings, a novel binding mechanism was proposed, highlighting the central role of the stem structure of the aptamer in binding and recognizing GlySMs and the auxiliary role of the mismatched bases in the adjacent loop. Guided by this binding mechanism, an aptamer with a higher 6'-sialyllactose binding affinity was designed, achieving a KD value of 4.54 ± 0.64 μM in vitro through a single shear and one mutation. The binding mechanism offers crucial guidance for designing high-affinity aptamers, enhancing the virtual screening efficiency for GlySMs. This streamlined workflow filters out ineffective binding sites, accelerating aptamer development and providing novel insights into glycan-nucleic acid interactions.

Investigation of interaction between boronic acids and sugar: effect of structural change of sugars on binding affinity using steady state and time resolved fluorescence spectroscopy and molecular docking

Binding interactions of boronic acid derivatives viz. 2-Methylphenylboronic acid (B1) and 3-Methoxyphenylboronic acid (B2) with mono saccharides (arabinose, fructose and galactose) and disaccharides (sucrose, lactose and maltose) in aqueous condition at pH 7.4 by means of fluorescence spectroscopy is reported in the present investigation. Sugar sensing as well as continuous glucose monitoring (CGM) plays a significant role in diabetes regulation. Sugar sensors mediated through enzymes have their own drawbacks, which led to encouragement to search for designing new sensors through alternate approaches. Among many, fluorescence-based sensors are drawing more attention. Boronic acid-based fluorescence sensors have the capacity to bind reversibly with diols, which makes their demand high in applications. Addition of sugar reduces fluorescence intensities. Change in intensities is associated to cleavage of intermolecular hydrogen bonding which leads in reduced stability of boronate ester. Lineweaver-Burk and Benesi-Hildebrand equation is used for analysing data. Mono sugars are estimated to have higher binding constants. Mutarotation leads to structural changes in saccharides which play a key role in binding interactions. Sugars in furanose form are found to be highly favoured for binding. Molecular docking of B1 and B2 with proteins with PDB ID: 2IPL and 2IPM being periplasmic was done with the help of Schrodinger Maestro 11.2 version. GLIDE scores terms are used for expressing binding affinity.

Maillard reaction induces changes in saccharides and amino acids during stir-baking of areca nuts

Purpose: To investigate changes in saccharides and amino acids induced by Maillard reaction (MR) during stir-baking of areca nuts (AN). Methods: The pH of aqueous extracts of AN and charred AN (CAN) were measured by a pH meter, and their absorbances at 420 nm were read in an ultraviolet-visible (UV-VIS) spectrophotometer. Changes in saccharides and amino acids were evaluated by high performance liquid chromatography (HPLC) and automated amino acid analyzer, respectively. Results: The pH of AN (5.85 ± 0.09) was lower than that of CAN (5.25 ± 0.04). Stir-baking significantly increased the A420 value of AN (0.32 ± 0.01 to 0.62 ± 0.02 (CAN). In addition, the contents of reducing saccharides (fructose and glucose) and free amino acids (serine, lysine, arginine and proline) were significantly decreased in the stir-baked CAN compared with AN. Conclusion: MR, during stir-baking of AN, decreases levels of free amino acids and reducing sugars due probably to the reaction between saccharides and amino acids. Keywords: Areca nut, Stir-baking, Maillard reaction, Reducing sugars, Free amino acids

Chemical alterations of pine wood saccharides during heat sterilisation.

Alterations in saccharides during heat sterilisation of pine wood (Pinus sylvestris L.) were investigated. The mass loss, extractives, lignin, cellulose, holocellulose and hemicelluloses were determined. Changes in saccharides were evaluated by the determination of monosaccharides in wood, size exclusion chromatography (SEC) as well as Fourier transform infrared (FTIR) spectroscopy. During heat sterilisation of pine wood the slight mass loss, an increase in extractives and a decrease in lignin and polysaccharides were observed. Hemicelluloses are degraded approximately twice as fast as cellulose. The degree of polymerisation of cellulose decreases approximately by 10% and it increases in holocellulose (by approx. 8%) as a result of a faster degradation of shorter hemicellulose chains. FTIR spectroscopy shows that sterilisation results in the deacetylation of cellulose and the formation of new carbonyl groups, an increase in the total crystallinity index (TCI) and a decrease in the lateral order index (LOI) and the hydrogen-bond intensity (HBI).

Metabolomics analysis of umbilical cord blood clarifies changes in saccharides associated with delivery method

BackgroundA metabolomic approach using umbilical cord blood from infants at birth has not been studied widely yet. AimWe examined changes in metabolite levels in umbilical cord blood at birth via gas chromatography/mass spectrometry (GC/MS)-based metabolomics, with the aim of achieving a detailed understanding of fetal stress during labor. Study designAll procedures were reviewed and approved by the Institutional Review Board of Kobe University School of Medicine. This was a cohort study of pregnant women based in Palmore Hospital, which is located in an urban area of Japan, and was carried out between December 2010 and May 2011. SubjectUmbilical cord arterial blood samples were obtained from 41 infants immediately after delivery. Outcome measuresMetabolites in the blood samples were measured using GC/MS to investigate whether the delivery method (spontaneous onset of labor, induction of labor or elective cesarean section) affected the metabolite profile in umbilical cord blood. ResultsElective cesarean section without labor led to lower levels of isoleucine, fructose, mannose, glucose, allose, glucuronic acid, inositol and cysteine in comparison with vaginal delivery following spontaneous labor and without medication. ConclusionIt is proposed that the stress associated with labor be involved in alterations in the levels of metabolites, particularly saccharides such as glucose, in umbilical cord blood.

Advancing monosaccharides as biomarkers: Part II. Effects of starvation and cadmium in Chironomus riparius as detected by fluorophore-assisted carbohydrate-electrophoresis

Saccharides were evaluated as biomarkers for cadmium (Cd) and starvation using fluorophore-assisted carbohydrate-electrophoresis (FACE) in 4th instar Chironomus riparius. FACE allowed different types of saccharides in whole larval homogenate to be analyzed simultaneously and in parallel with other larval samples. Larval homogenates showed seven principle bands labeled A, B, C, D, E, F and G. Previous work found that the migration patterns of bands A, C, D and F matched those of ribose, glucose, galactose and fructose, respectively. Four of the bands, B, C, E and G were generated from glucose-based mono, oligo, and polysaccharides. Band B was primarily derived from glucose and band E from glycogen. Experiments (0–72 h) with starved larvae showed a time dependent reduction in bands B and E that was statistically significant at 72 h. Experiments with Cd (0.01–1000 μM) showed a concentration and time dependent reduction in band E with a LOEL of 1 μM and NOEL of 0.01 μM at 48 h. The LOEL was 0.014% of the 48 h LC50. Significant reduction of band E only occurred in fed larvae indicating that food was an important route of exposure. Reductions in saccharides were independent of larval weight loss at 48 h. This suggested that major changes in saccharides were not due to weight loss but metabolic stress in the presence of Cd.

イチジク果実の生育に伴う糖質変化および糖質代謝に関与する酵素活性の挙動

イチジク果実の生育に伴う糖質変化および糖質代謝に関与する酵素活性の挙動