-
PloS One 2014The objective of this research was to determine the effect of sugar or fatty acid in sugar ester compounds on the surface-active properties and antimicrobial activities...
The objective of this research was to determine the effect of sugar or fatty acid in sugar ester compounds on the surface-active properties and antimicrobial activities of these compounds. Disaccharides of medium-chain fatty acid monoesters were synthesized through transesterifications by immobilized lipase (Lipozyme TLIM) to yield nine monoesters for subsequent study. Their antimicrobial activities were investigated using three pathogenic microorganisms: Staphylococcus aureus, Escherichia coli O157:H7 and Candida albicans. Their surface-active properties including air-water surface tension, critical micelle concentration, and foaming and emulsion power and stability were also studied. The results showed that all of the tested monoesters were more effective against Staphylococcus aureus (Gram-positive bacterium) than against Escherichia coli O157:H7 (Gram-negative bacterium). The results demonstrated that the carbon chain length was the most important factor influencing the surface properties, whereas degree of esterification and hydrophilic groups showed little effect.
Topics: Air; Anti-Infective Agents; Candida albicans; Disaccharides; Drug Stability; Enzymes, Immobilized; Escherichia coli O157; Esters; Lipase; Micelles; Microbial Sensitivity Tests; Staphylococcus aureus; Surface Tension; Thermodynamics; Water
PubMed: 25531369
DOI: 10.1371/journal.pone.0114845 -
Chemistry (Weinheim An Der Bergstrasse,... Jun 2022TLR4 is a key pattern recognition receptor that can sense pathogen- and danger- associated molecular patterns to activate the downstream signaling pathways which results...
TLR4 is a key pattern recognition receptor that can sense pathogen- and danger- associated molecular patterns to activate the downstream signaling pathways which results in the upregulation of transcription factors and expression of interferons and cytokines to mediate protective pro-inflammatory responses involved in immune defense. Bacterial lipid A is the primary TLR4 ligand with very complex, species-specific, and barely predictable structure-activity relationships. Given that therapeutic targeting of TLR4 is an emerging tool for management of a variety of human diseases, the development of novel TLR4 activating biomolecules other than lipid A is of vast importance. We report on design, chemical synthesis and immunobiology of novel glycan-based lipid A-mimicking molecules that can activate human and murine TLR4-mediated signaling with picomolar affinity. Exploiting crystal structure - based design we have created novel disaccharide lipid A mimetics (DLAMs) where the inherently flexible β(1→6)-linked diglucosamine backbone of lipid A is exchanged with a conformationally restrained non-reducing βGlcN(1↔1')βGlcN scaffold. Excellent stereoselectivity in a challenging β,β-1,1' glycosylation was achieved by tuning the reactivities of donor and acceptor molecules using protective group manipulation strategy. Divergent streamlined synthesis of β,β-1,1'-linked diglucosamine-derived glycolipids entailing multiple long-chain (R)-3- acyloxyacyl residues and up two three phosphate groups was developed. Specific 3D-molecular shape and conformational rigidity of unnatural β,β-1,1'-linked diglucosamine combined with carefully optimized phosphorylation and acylation pattern ensured efficient induction of the TLR4-mediated signaling in a species-independent manner.
Topics: Adjuvants, Immunologic; Animals; Disaccharides; Humans; Immunotherapy; Lipid A; Mice; Prospective Studies; Toll-Like Receptor 4
PubMed: 35439332
DOI: 10.1002/chem.202200547 -
Scientific Reports Apr 2022Oritavancin is a semisynthetic glycopeptide antibiotic used to treat severe infections by multidrug-resistant Gram-positive pathogens. Oritavancin is known to be a...
Oritavancin is a semisynthetic glycopeptide antibiotic used to treat severe infections by multidrug-resistant Gram-positive pathogens. Oritavancin is known to be a thousand times more potent than vancomycin against Gram-positive bacteria due to the additional interactions with bacterial peptidoglycan (PG) facilitated by a secondary-binding site. The presence of this secondary-binding site is evident in desleucyl-oritavancin, an Edman degradation product of oritavancin, still retaining its potency against Gram-positive bacteria, whereas desleucyl-vancomycin is devoid of any antimicrobial activities. Herein, using explicit solvent molecular dynamics (MD) simulations, steered MD simulations, and umbrella sampling, we show evidence of a secondary-binding site mediated by the disaccharide-modified hydrophobic sidechain of oritavancin interactions with the pentaglycyl-bridge segment of the PG. The interactions were characterized through comparison to the interaction of PG with chloroeremomycin, vancomycin, and the desleucyl analogs of the glycopeptides. Our results show that the enhanced binding of oritavancin to PG over the binding of the other complexes studied is due to an increase in the hydrophobic effect, electrostatic and van der Waals interactions, and not the average number of hydrogen bonds. Our ranking of the binding interactions of the biomolecular complexes directly correlates with the order based on their experimental minimum inhibitory concentrations. The results of our simulations provide insight into the modification of glycopeptides to increase their antimicrobial activities or the design of novel antibiotics against pathogenic Gram-positive bacteria.
Topics: Anti-Bacterial Agents; Binding Sites; Disaccharides; Glycopeptides; Gram-Positive Bacteria; Molecular Dynamics Simulation; Peptidoglycan; Vancomycin
PubMed: 35490171
DOI: 10.1038/s41598-022-10735-6 -
New Biotechnology Sep 2022The aim of this study was to establish an efficient bioprocess for the synthesis of trehalulose as a novel sweetener. This disaccharide has 70% of the sweetness of...
The aim of this study was to establish an efficient bioprocess for the synthesis of trehalulose as a novel sweetener. This disaccharide has 70% of the sweetness of sucrose and bioactive properties such as anti-cariogenicity and anti-oxidizing activity. In this study, amylosucrase from the Deinococcus deserti (DdAS) gene was expressed and purified. When DdAS was reacted with 2 M sucrose at 35 °C for 120 h, the yield ratio of trehalulose to turanose was approximately 2:1. The trehalulose yield increased when extrinsic fructose was added. Under optimum conditions for trehalulose synthesis, the yield reached 36% (246 g/L, sucrose basis) starting with 2 M sucrose + 0.75 M fructose and showed the highest trehalulose productivity (1.94 g/L/h). As a result, a novel amylosucrase that synthesized trehalulose as the major product was developed, in contrast to other studied amylosucrase-type enzymes. DdAS could be utilized industrially in a bioprocess for producing trehalulose as a functional sucrose alternative.
Topics: Deinococcus; Disaccharides; Fructose; Glucosyltransferases; Sucrose
PubMed: 35339700
DOI: 10.1016/j.nbt.2022.03.004 -
Journal of Chromatography. A May 2020In the present study, we describe the development of a fast, 2-step salt gradient for analysis of chondroitin sulfate disaccharides. Using salt gradients, which is...
In the present study, we describe the development of a fast, 2-step salt gradient for analysis of chondroitin sulfate disaccharides. Using salt gradients, which is somewhat unusual in HILIC-based separations, provides relatively fast chromatography with excellent sensitivity (15 min cycle time, 10-20 fmol/µL detection, 30-50 fmol/µL quantitation limit), and good linearity. The efficiency of the new method is demonstrated by measuring human tissue slices of healthy, cirrhotic, and cancerous liver samples. Preliminary results show major differences among the quantity and sulfation pattern of the various sample types.
Topics: Chondroitin Sulfates; Chromatography, High Pressure Liquid; Disaccharides; Humans; Liver; Sodium Chloride
PubMed: 32093904
DOI: 10.1016/j.chroma.2020.460979 -
Biochemistry Nov 2014The bleomycins (BLMs) are a family of antitumor antibiotics used clinically for anticancer chemotherapy. Their antitumor selectivity derives at least in part from their...
The bleomycins (BLMs) are a family of antitumor antibiotics used clinically for anticancer chemotherapy. Their antitumor selectivity derives at least in part from their ability to target tumor cells, a property that resides in the carbohydrate moiety of the antitumor agent. In earlier studies, we have demonstrated that the tumor cell selectivity resides in the mannose carbamoyl moiety of the BLM saccharide and that both the BLM disaccharide and monosaccharide containing the carbamoyl moiety were capable of the delivery/uptake of a conjugated cyanine dye into cultured cancer cell lines. Presently, the nature of the participation of the carbamoyl moiety has been explored further to provide compounds of utility for defining the nature of the mechanism of tumor cell recognition and uptake by BLM saccharides and in the hope that more efficient compounds could be identified. A library of seven disaccharide-Cy5** dye conjugates was prepared that are structural analogues of the BLM disaccharide. These differed from the natural BLM disaccharide in the position, orientation, and substitution of the carbamoyl group. Studies of these compounds in four matched sets of tumor and normal cell lines revealed a few that were both tumor cell selective and internalized 2-4-fold more efficiently than the natural BLM disaccharide.
Topics: Antibiotics, Antineoplastic; Bleomycin; Carbocyanines; Cell Line, Tumor; Disaccharides; Drug Delivery Systems; Humans; Neoplasms
PubMed: 25272367
DOI: 10.1021/bi501102z -
The Journal of Biological Chemistry Jun 2018Structural characterization of glycosaminoglycans remains a challenge but is essential for determining structure-function relationships between glycosaminoglycans and...
Structural characterization of glycosaminoglycans remains a challenge but is essential for determining structure-function relationships between glycosaminoglycans and the biomolecules with which they interact and for gaining insight into the biosynthesis of glycosaminoglycans. We have recently reported that xyloside-primed chondroitin/dermatan sulfate derived from a human breast carcinoma cell line, HCC70, has cytotoxic effects and shown that it differs in disaccharide composition from nontoxic chondroitin/dermatan sulfate derived from a human breast fibroblast cell line, CCD-1095Sk. To further investigate the structural requirements for the cytotoxic effect, we developed a novel LC-MS/MS approach based on reversed-phase dibutylamine ion-pairing chromatography and negative-mode higher-energy collision dissociation and used it in combination with cell growth studies and disaccharide fingerprinting. This strategy enabled detailed structural characterization of linkage regions, internal oligosaccharides, and nonreducing ends, revealing not only differences between xyloside-primed chondroitin/dermatan sulfate from HCC70 cells and CCD-1095Sk cells, but also sialylation of the linkage region and previously undescribed methylation and sulfation of the nonreducing ends. Although the xyloside-primed chondroitin/dermatan sulfate from HCC70 cells was less complex in terms of presence and distribution of iduronic acid than that from CCD-1095Sk cells, both glucuronic acid and iduronic acid appeared to be essential for the cytotoxic effect. Our data have moved us one step closer to understanding the structure of the cytotoxic chondroitin/dermatan sulfate from HCC70 cells primed on xylosides and demonstrate the suitability of the LC-MS/MS approach for structural characterization of glycosaminoglycans.
Topics: Cell Line, Tumor; Chondroitin Sulfates; Chromatography, Liquid; Dermatan Sulfate; Disaccharides; Glycosaminoglycans; Glycosides; Humans; Tandem Mass Spectrometry
PubMed: 29739851
DOI: 10.1074/jbc.RA118.002971 -
The Plant Journal : For Cell and... Oct 2022Grass xylan, the major hemicellulose in both primary and secondary cell walls, is heavily decorated with α-1,3-linked arabinofuranosyl (Araf) residues that may be...
Grass xylan, the major hemicellulose in both primary and secondary cell walls, is heavily decorated with α-1,3-linked arabinofuranosyl (Araf) residues that may be further substituted at O-2 with xylosyl (Xyl) or Araf residues. Although xylan 3-O-arabinosyltransferases (XATs) catalyzing 3-O-Araf addition onto xylan have been characterized, glycosyltransferases responsible for the transfer of 2-O-Xyl or 2-O-Araf onto 3-O-Araf residues of xylan to produce the Xyl-Araf and Araf-Araf disaccharide side chains remain to be identified. In this report, we showed that a rice GT61 member, named OsXAXT1 (xylan arabinosyl 2-O-xylosyltransferase 1) herein, was able to mediate the addition of Xyl-Araf disaccharide side chains onto xylan when heterologously co-expressed with OsXAT2 in the Arabidopsis gux1/2/3 (glucuronic acid substitution of xylan 1/2/3) triple mutant that lacks any glycosyl substitutions. Recombinant OsXAXT1 protein expressed in human embryonic kidney 293 cells exhibited a xylosyltransferase activity catalyzing the addition of Xyl from UDP-Xyl onto arabinosylated xylooligomers. Consistent with its function as a xylan arabinosyl 2-O-xylosyltransferase, CRISPR-Cas9-mediated mutations of the OsXAXT1 gene in transgenic rice plants resulted in a reduction in the level of Xyl-Araf disaccharide side chains in xylan. Furthermore, we revealed that XAXT1 close homologs from several other grass species, including switchgrass, maize, and Brachypodium, possessed the same functions as OsXAXT1, indicating functional conservation of XAXTs in grass species. Together, our findings establish that grass XAXTs are xylosyltransferases catalyzing Xyl transfer onto O-2 of Araf residues of xylan to form the Xyl-Araf disaccharide side chains, which furthers our understanding of genes involved in xylan biosynthesis.
Topics: Arabidopsis; Cell Wall; Disaccharides; Glucuronic Acid; Glycosyltransferases; Humans; Oryza; Pentosyltransferases; Plants, Genetically Modified; Uridine Diphosphate; Xylans; UDP Xylose-Protein Xylosyltransferase
PubMed: 35959609
DOI: 10.1111/tpj.15939 -
Journal of the American Chemical Society Oct 2014The disaccharide moiety is responsible for the tumor cell targeting properties of bleomycin (BLM). While the aglycon (deglycobleomycin) mediates DNA cleavage in much the...
The disaccharide moiety is responsible for the tumor cell targeting properties of bleomycin (BLM). While the aglycon (deglycobleomycin) mediates DNA cleavage in much the same fashion as bleomycin, it exhibits diminished cytotoxicity in comparison to BLM. These findings suggested that BLM might be modular in nature, composed of tumor-seeking and tumoricidal domains. To explore this possibility, BLM analogues were prepared in which the disaccharide moiety was attached to deglycobleomycin at novel positions, namely, via the threonine moiety or C-terminal substituent. The analogues were compared with BLM and deglycoBLM for DNA cleavage, cancer cell uptake, and cytotoxic activity. BLM is more potent than deglycoBLM in supercoiled plasmid DNA relaxation, while the analogue having the disaccharide on threonine was less active than deglycoBLM and the analogue containing the C-terminal disaccharide was slightly more potent. While having unexceptional DNA cleavage potencies, both glycosylated analogues were more cytotoxic to cultured DU145 prostate cancer cells than deglycoBLM. Dye-labeled conjugates of the cytotoxic BLM aglycons were used in imaging experiments to determine the extent of cell uptake. The rank order of internalization efficiencies was the same as their order of cytotoxicities toward DU145 cells. These findings establish a role for the BLM disaccharide in tumor targeting/uptake and suggest that the disaccharide moiety may be capable of delivering other cytotoxins to cancer cells. While the mechanism responsible for uptake of the BLM disaccharide selectively by tumor cells has not yet been established, data are presented which suggest that the metabolic shift to glycolysis in cancer cells may provide the vehicle for selective internalization.
Topics: Bleomycin; Cell Line; Cell Survival; DNA Cleavage; Disaccharides; Dose-Response Relationship, Drug; Humans; Male; Molecular Structure; Prostatic Neoplasms; Structure-Activity Relationship
PubMed: 25184545
DOI: 10.1021/ja507255g -
Advances in Therapy Mar 2020Intravenous (IV) iron is typically the preferred treatment for patients with iron deficiency anemia (IDA) who cannot tolerate or absorb oral iron, or who require fast...
INTRODUCTION
Intravenous (IV) iron is typically the preferred treatment for patients with iron deficiency anemia (IDA) who cannot tolerate or absorb oral iron, or who require fast replenishment of iron stores pre-operatively. Several IV iron formulations are available with different dosing characteristics affecting infusion speed and maximum dose. The aim was to develop a resource impact model to calculate the cost of establishing an IV iron clinic and model resource impact of different IV irons to inform clinicians and service providers implementing innovative pre-operative IV iron services in Ireland.
METHODS
A resource impact tool was developed to model resource utilization and IDA treatment costs. Two fast-administration, high-dose formulations of IV iron are available in Ireland: iron isomaltoside 1000/ferric derisomaltose (IIM) and ferric carboxymaltose (FCM). The tool modeled clinic throughput based on their different dosing characteristics in a specific IDA population, capturing fixed overheads, variable costs, clinic income from private and publicly-funded patients, and savings associated with IV iron.
RESULTS
Based on a 70:30 split between public and private patients in a new pre-operative service with capacity for 12 infusion slots weekly, IIM would facilitate correction of iron deficits in 474 patients annually, resulting in a net annual clinic balance of €42,736 on income of €159,887 and net costs of €117,151. FCM would facilitate treatment of 353 patients, resulting in a net annual clinic balance of €36,327 on income of €116,050 and costs of €79,722, a difference of €6408 and 121 patients treated in favor of using IIM over FCM.
CONCLUSION
Based on this provider-perspective analysis, IIM would maximize clinic throughput relative to other IV iron formulations, allowing clinicians in Ireland to optimize their current service provision and expenditure, and model the impact of introducing IV iron clinics for pre-operative patients with IDA.
Topics: Administration, Intravenous; Ambulatory Care Facilities; Anemia, Iron-Deficiency; Costs and Cost Analysis; Disaccharides; Ferric Compounds; Health Resources; Humans; Ireland; Maltose; Models, Economic; Preoperative Care
PubMed: 32030608
DOI: 10.1007/s12325-020-01241-0