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Analytical and Bioanalytical Chemistry Apr 2021β-Galactosidase (β-Gal) is a widely used enzyme as a reporter gene in the field of molecular biology which hydrolyzes the β-galactosides into monosaccharides. β-Gal... (Review)
Review
β-Galactosidase (β-Gal) is a widely used enzyme as a reporter gene in the field of molecular biology which hydrolyzes the β-galactosides into monosaccharides. β-Gal is an essential enzyme in humans and its deficiency or its overexpression results in several rare diseases. Cellular senescence is probably one of the most relevant physiological disorders that involve β-Gal enzyme. In this review, we assess the progress made to date in the design of molecular-based probes for the detection of β-Gal both in vitro and in vivo. Most of the reported molecular probes for the detection of β-Gal consist of a galactopyranoside residue attached to a signalling unit through glycosidic bonds. The β-Gal-induced hydrolysis of the glycosidic bonds released the signalling unit with remarkable changes in color and/or emission. Additional examples based on other approaches are also described. The wide applicability of these probes for the rapid and in situ detection of de-regulation β-Gal-related diseases has boosted the research in this fertile field.
Topics: Animals; Cellular Senescence; Colorimetry; Enzyme Assays; Fluorescent Dyes; Galactose; Galactosides; Humans; Hydrolysis; Molecular Probes; beta-Galactosidase
PubMed: 33606064
DOI: 10.1007/s00216-020-03111-8 -
Molecules (Basel, Switzerland) Oct 2022Tea is the first most popular beverage worldwide and is available in several selections such as black (fully oxidized), Oolong (partially oxidized) and green...
Tea is the first most popular beverage worldwide and is available in several selections such as black (fully oxidized), Oolong (partially oxidized) and green (non-oxidized), in addition to purple tea, an emerging variety derived from the same tea plant (). This study investigated purple tea leaves (non-oxidized) and flakes (water extractable) to thoroughly identify their composition of anthocyanins and catechins and to study the effect of a water extraction process on their compositional properties in comparison with green tea. Anthocyanin and catechin compounds were separated and quantified using UPLC, and their identity was confirmed using LC-MS/MS in positive and negative ionization modes. Delphinidin was the principal anthocyaninidin in purple tea, while cyanidin came in second. The major anthocyanin pigments in purple tea were delphinidin-coumaroyl-hexoside followed by delphinidin-3-galactoside and cyanidin-coumaroyl-hexoside. The water extraction process resulted in substantial reductions in anthocyanins in purple tea flakes. There were no anthocyanin compounds detected in green tea samples. Both purple and green tea types were rich in catechins, with green tea containing higher concentrations than purple tea. The main catechin in purple or green tea was epigallocatechin gallate (EGCG) followed by either epicatechin gallate (ECG) or epigallocatechin (EGC), subject to tea type. The extraction process increased the concentration of catechins in both purple and green tea flakes. The results suggest that purple tea holds promise in making healthy brews, natural colorants and antioxidants and/or functional ingredients for beverages, cosmetics and healthcare industries due to its high content of anthocyanins and catechins.
Topics: Anthocyanins; Camellia sinensis; Catechin; Chromatography, Liquid; Galactosides; Plant Leaves; Tandem Mass Spectrometry; Tea; Water
PubMed: 36235212
DOI: 10.3390/molecules27196676 -
International Journal of Molecular... Feb 2021Cyanidin 3--galactoside (Cy3Gal) is one of the most widespread anthocyanins that positively impacts the health of animals and humans. Since it is available from a wide... (Review)
Review
Cyanidin 3--galactoside (Cy3Gal) is one of the most widespread anthocyanins that positively impacts the health of animals and humans. Since it is available from a wide range of natural sources, such as fruits (apples and berries in particular), substantial studies were performed to investigate its biosynthesis, chemical stability, natural occurrences and content, extraction methods, physiological functions, as well as potential applications. In this review, we focus on presenting the previous studies on the abovementioned aspects of Cy3Gal. As a conclusion, Cy3Gal shares a common biosynthesis pathway and analogous stability with other anthocyanins. Galactosyltransferase utilizing uridine diphosphate galactose (UDP-galactose) and cyanidin as substrates is unique for Cy3Gal biosynthesis. Extraction employing different methods reveals chokeberry as the most practical natural source for mass-production of this compound. The antioxidant properties and other health effects, including anti-inflammatory, anticancer, antidiabetic, anti-toxicity, cardiovascular, and nervous protective capacities, are highlighted in purified Cy3Gal and in its combination with other polyphenols. These unique properties of Cy3Gal are discussed and compared with other anthocyanins with related structure for an in-depth evaluation of its potential value as food additives or health supplement. Emphasis is laid on the description of its physiological functions confirmed via various approaches.
Topics: Animals; Anthocyanins; Anti-Inflammatory Agents; Antineoplastic Agents; Biological Products; Fruit; Galactosides; Humans; Hypoglycemic Agents; Phytochemicals; Plant Extracts
PubMed: 33668383
DOI: 10.3390/ijms22052261 -
International Journal of Molecular... Jan 2018Galectins are β-galactoside-binding proteins. As carbohydrate-binding proteins, they participate in intracellular trafficking, cell adhesion, and cell-cell signaling.... (Review)
Review
Galectins are β-galactoside-binding proteins. As carbohydrate-binding proteins, they participate in intracellular trafficking, cell adhesion, and cell-cell signaling. Accumulating evidence indicates that they play a pivotal role in numerous physiological and pathological activities, such as the regulation on cancer progression, inflammation, immune response, and bacterial and viral infections. Galectins have drawn much attention as targets for therapeutic interventions. Several molecules have been developed as galectin inhibitors. In particular, TD139, a thiodigalactoside derivative, is currently examined in clinical trials for the treatment of idiopathic pulmonary fibrosis. Herein, we provide an in-depth review on the development of galectin inhibitors, aiming at the dissection of the structure-activity relationship to demonstrate how inhibitors interact with galectin(s). We especially integrate the structural information established by X-ray crystallography with several biophysical methods to offer, not only in-depth understanding at the molecular level, but also insights to tackle the existing challenges.
Topics: Animals; Binding Sites; Galectins; Humans; Molecular Docking Simulation; Protein Binding; Quantitative Structure-Activity Relationship; Thiogalactosides
PubMed: 29382172
DOI: 10.3390/ijms19020392 -
Chimia 2011Evidence that the galectin family of proteins plays crucial roles in cancer, inflammation, and immunity has accumulated over the last decade. The galectins have... (Review)
Review
Evidence that the galectin family of proteins plays crucial roles in cancer, inflammation, and immunity has accumulated over the last decade. The galectins have consequently emerged as interesting drug targets. A majority of galectin functions occurs by means of cross-linking glycoproteins and by doing so controlling glycoprotein cellular localization and residence times. The glycoprotein cross-linking occurs when galectin dimers or multimers, or galectins with two binding sites, bind galactose-containing glycans of the glycoproteins. Such galectin-glycan interactions have been successfully blocked with compounds having multivalent presentation of galactose, lactose, or N-acetyllactosamine, with peptides, and with small carbohydrate (galactose) derivatives. This review summarizes and analyzes attempts to develop efficient and selective small-molecule galectin inhibitors through derivatization of monosaccharides, mainly galactosides, with non-carbohydrate structures that protrude into subsites adjacent to the core-conserved galactose-recognizing site of the galectins.
Topics: Drug Design; Galactosides; Galectins; Molecular Weight; Monosaccharides; Structure-Activity Relationship
PubMed: 21469439
DOI: 10.2533/chimia.2011.18 -
Molecules (Basel, Switzerland) Sep 2022α-Galactosidase (EC 3.2.1.22) refers to a group of enzymes that hydrolyze oligosaccharides containing α-galactoside-banded glycosides, such as stachyose, raffinose,...
α-Galactosidase (EC 3.2.1.22) refers to a group of enzymes that hydrolyze oligosaccharides containing α-galactoside-banded glycosides, such as stachyose, raffinose, and verbascose. These enzymes also possess great potential for application in sugar production, and in the feed and pharmaceutical industries. In this study, a strain of (WHPC005) that produces α-galactosidase was identified from the soil of Western Hunan, China. It was determined that the optimal temperature and pH for this α-galactosidase were 45 °C and 5.5, respectively. The activity of α-galactosidase was inhibited by K, Al, Fe, fructose, sucrose, lactose, galactose, SDS, EDTA, NaCl, and (NH)SO, and enhanced by Ca, Fe, Mn, Zn, glucose, and raffinose. The optimal inducer was raffinose, and the optimal induction concentration was 30 μmol/L. The α-galactosidase gene was cloned using random fragment cloning methods. Sequence analysis demonstrated that the open reading frame of the α-galactosidase gene was 1230 bp, which encodes a putative protein of 409 amino acids in length. Bioinformatics analysis showed that the isoelectric point and molecular weight of this α-galactosidase were 4.84 and 47.40 kD, respectively. Random coils, alpha helixes, and beta turns were observed in its secondary structure, and conserved regions were found in the tertiary structure of this α-galactosidase. Therefore, this α-galactosidase-producing bacterial strain has the potential for application in the feed industry.
Topics: Amino Acids; Carnobacteriaceae; Edetic Acid; Fructose; Galactose; Galactosides; Glucose; Glycosides; Hydrogen-Ion Concentration; Kinetics; Lactose; Oligosaccharides; Raffinose; Sodium Chloride; Soil; Substrate Specificity; Sucrose; alpha-Galactosidase
PubMed: 36144675
DOI: 10.3390/molecules27185942 -
Frontiers in Bioscience (Scholar... Jan 2012Galectins (GALs) are evolutionarily-conserved lectins defined by at least one carbohydrate recognition domain (CRD) with affinity for beta-galactosides and conserved... (Review)
Review
Galectins (GALs) are evolutionarily-conserved lectins defined by at least one carbohydrate recognition domain (CRD) with affinity for beta-galactosides and conserved sequence motifs. Although the biological roles of some members of this family, including the 'proto-type' GAL-1 and the 'chimera-type' GAL-3 have been widely studied, the functions of 'tandem-repeat' galectins are just emerging. The subgroup of 'tandem-repeat' galectins (GAL-4, -6, -8, -9, and -12) contain two distinct CRDs, connected by a linker peptide. Here we integrated and distilled the available information on 'tandem-repeat' galectins, their specific structures, potential ligands and biological activities in inflammatory and neoplastic diseases. While GAL-4 has been implicated in inflammatory bowel diseases, either as a pro-inflammatory or pro-apoptotic mediator, GAL-8 plays roles in autoimmune diseases such as rheumatoid arthritis and lupus erythematosus and modulates tumor progression. GAL-9 controls allergic inflammation and Th1/Th17-mediated autoimmunity and has prognostic value in certain tumor types. Finally, GAL-12 plays important roles in adipocyte physiology. Although this information is just emerging, further studies are needed to dissect the biological roles of 'tandem-repeat' galectins in health and disease.
Topics: Animals; Conserved Sequence; Galactosides; Galectins; Humans; Ligands; Protein Structure, Tertiary; Structure-Activity Relationship; Tandem Repeat Sequences
PubMed: 22202096
DOI: 10.2741/s305 -
Proceedings of the National Academy of... Dec 2018The lactose permease of (LacY) utilizes an alternating access symport mechanism with multiple conformational intermediates, but only inward (cytoplasmic)- or outward...
The lactose permease of (LacY) utilizes an alternating access symport mechanism with multiple conformational intermediates, but only inward (cytoplasmic)- or outward (periplasmic)-open structures have been characterized by X-ray crystallography. It is demonstrated here with sugar-binding studies that cross-linking paired-Cys replacements across the closed cytoplasmic cavity stabilize an occluded conformer with an inaccessible sugar-binding site. In addition, a nanobody (Nb) that stabilizes a periplasmic-open conformer with an easily accessible sugar-binding site in WT LacY fails to cause the cytoplasmic cross-linked mutants to become accessible to galactoside, showing that the periplasmic cavity is closed. These results are consistent with tight association of the periplasmic ends in two pairs of helices containing clusters of small residues in the packing interface between N- and C-terminal six-helix bundles of the symporter. However, after reduction of the disulfide bond, the Nb markedly increases the rate of galactoside binding, indicating unrestricted access to the Nb epitope and the galactoside-binding site from the periplasm. The findings indicate that the cross-linked cytoplasmic double-Cys mutants resemble an occluded apo-intermediate in the transport cycle.
Topics: Binding Sites; Crystallography, X-Ray; Cytoplasm; Escherichia coli; Escherichia coli Proteins; Galactosides; Membrane Transport Proteins; Monosaccharide Transport Proteins; Periplasm; Symporters
PubMed: 30478058
DOI: 10.1073/pnas.1816267115 -
Parasitology May 2021Galectins are a family of proteins that bind β-galactosides and play key roles in a variety of cellular processes including host defence. They have been well studied in... (Review)
Review
Galectins are a family of proteins that bind β-galactosides and play key roles in a variety of cellular processes including host defence. They have been well studied in hosts but less so in gastrointestinal nematodes. Both host and parasite galectins are present in the gastrointestinal tract following infection. Parasite galectins can both bind antibody, especially highly glycosylated IgE and be bound by antibody. Parasite galectins may act as molecular sponges that soak up antibody. Host galectins promote mast cell degranulation while parasite galectins inhibit degranulation. Host and parasite galectins can also bind mucins and influence mucus viscosity. As the protective response against gastrointestinal nematode infection is partly dependent on IgE mediated mast cell degranulation and mucus, the interactions between host and parasite galectins play key roles in determining the outcome of infection.
Topics: Animals; Galactosides; Galectins; Host-Parasite Interactions; Molecular Structure; Nematode Infections; Polysaccharides
PubMed: 33461629
DOI: 10.1017/S003118202100007X -
Medicina (Kaunas, Lithuania) Apr 2018Lactose-derived prebiotics provide wide ranges of gastrointestinal comforts. In this review article, the probable biochemical mechanisms through which lactose-derived... (Review)
Review
Lactose-derived prebiotics provide wide ranges of gastrointestinal comforts. In this review article, the probable biochemical mechanisms through which lactose-derived prebiotics offer positive gastrointestinal health are reported along with the up-to-date results of clinical investigations; this might be the first review article of its kind, to the best of our knowledge. Lactose-derived prebiotics have unique biological and functional values, and they are confirmed as 'safe' by the Food and Drug Administration federal agency. Medical practitioners frequently recommend them as therapeutics as a pure form or combined with dairy-based products (yoghurt, milk and infant formulas) or fruit juices. The biological activities of lactose-derived prebiotics are expressed in the presence of gut microflora, mainly probiotics ( spp. in the small intestine and spp. in the large intestine). Clinical investigations reveal that galacto-oligosaccharide reduces the risks of several types of diarrhea (traveler's diarrhea, osmotic diarrhea and Clostridium difficile associated relapsing diarrhea). Lactulose and lactosucrose prevent inflammatory bowel diseases (Crohn's disease and ulcerative colitis). Lactulose and lactitol reduce the risk of hepatic encephalopathy. Furthermore, lactulose, galacto-oligosaccharide and lactitol prevent constipation in individuals of all ages. It is expected that the present review article will receive great attention from medical practitioners and food technologists.
Topics: Cathartics; Colonic Neoplasms; Constipation; Diarrhea; Galactosides; Gastrointestinal Diseases; Gastrointestinal Tract; Hepatic Encephalopathy; Humans; Inflammatory Bowel Diseases; Lactose; Lactulose; Oligosaccharides; Prebiotics; Probiotics; Sugar Alcohols; Trisaccharides
PubMed: 30344249
DOI: 10.3390/medicina54020018