Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

From a mixture of N-acetylglucosaminyl-beta-cyclodextrin (GlcNAc-betaCD) and lactose, beta-D-galactosyl-GlcNAc-betaCD (Gal-GlcNAc-betaCD) was synthesized by the transfer action of beta-galactosidase. GlcNAc-maltotriose (Glc3) and Gal-GlcNAc-Glc3 were produced with hydrolysis of GlcNAc-betaCD by cyclodextrin glycosyltransferase, and Gal-GlcNAc-betaCD by bacterial saccharifying alpha-amylase respectively. Finally, GlcNAc-Glc3-betaCD and Gal-GlcNAc-Glc3-betaCD were synthesized in 5.2% and 3.5% yield when Klebsiella pneumoniae pullulanase was incubated with the mixture of GlcNAc-Glc(3) and betaCD, or Gal-GlcNAc-Glc3 and betaCD respectively. The structures of GlcNAc-Glc3-betaCD and Gal-GlcNAc-Glc3-betaCD were analyzed by FAB-MS and NMR spectroscopy and identified as 6-O-alpha-(6(3)-O-beta-D-N-acetylglucosaminyl-maltotriosyl)-betaCD, and 6-O-alpha-(4-O-beta-D-galactopyranosyl-6(3)-O-beta-D-N-acetylglucosaminyl-maltotriosyl)-betaCD respectively.
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PMID:Synthesis of novel heterobranched beta-cyclodextrins having beta-D-N-acetylglucosaminyl-maltotriose on the side chain. 1584 11

Aminoethyl-chitin (AEC) was synthesized in an attempt to both increase solubility of chitin in water and biological activity. AEC was obtained by grafting 2-chloroethylamino hydrochloride onto chitin at C-6 position. The structure of AEC was elucidated FT-IR and (1)H NMR spectroscopy, and its antimicrobial activity was investigated using three Gram-positive and Gram-negative bacteria. The integrity of the cell membranes of the representatives E. coli and S. aureus was investigated by determining the release of intracellular components of cells. When treated with AEC, release of 260 nm absorbing materials quickly increased both E. coli and S. aureus, but absorbance value was different due to the difference in cell structures. For detailed study, outer membrane (OM) and inner membrane (IM) permeabilization assay were performed using the fluorescent probe 1-N-phenylnaphthylamine (NPN) and the release of cytoplasmic beta-galactosidase activity. The results showed that AEC rapidly increased NPN uptake and the release of cytoplasmic beta-galactosidase via increasing the permeability of OM and IM. In addition, cytotoxic effect of AEC was assessed using human lung fibroblast (MRC-5) cell line, and AEC showed less toxic against MRC-5.
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PMID:Antimicrobial action of novel chitin derivative. 1627 Dec 84

Pep-1 is a tryptophane-rich cell-penetrating peptide (CPP) that has been previously proposed to bind protein cargoes by hydrophobic assembly and translocate them across cellular membranes. To date, however, the molecular mechanisms responsible for cargo binding and translocation have not been clearly identified. This study was conducted to gain insight into the interaction between Pep-1 with its cargo and the biological membrane to identify the thereby involved structural elements crucial for translocation. We studied three peptides differing in their N- and C-termini: (i) Pep-1, carrying an acetylated N-terminus and a C-terminal cysteamine elongation, (ii) AcPepWAmide, with an acetylated N-terminus and an amidated C-terminus, and (iii) PepW, with two free termini. Thioredoxin (TRX) and beta-galactosidase were used as protein cargoes. To study CPP-membrane interactions, we performed biophysical as well as biological assays. To mimic biological membranes, we used phospholipid liposomes in a dye leakage assay and surfactant micelles for high-resolution NMR studies. In addition, membrane integrity, cell viability, and translocation efficiency were analyzed in HeLa cells. An alpha-helical structure was found for all peptides in the hydrophobic N-terminal region encompassing residues 4-13, whereas the hydrophilic region remained unstructured in the presence of micelles. Our results show that the investigated peptides interacted with the micelles as well as with the protein cargo via their tryptophan-rich domain. All peptides displayed an orientation parallel to the micelle surface. The C-terminal cysteamine group formed an additional membrane anchor, leading to more efficient translocation properties in cells. No membrane permeabilization was observed, and our data were largely compatible with an endocytic pathway for cellular uptake.
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PMID:Biophysical and biological studies of end-group-modified derivatives of Pep-1. 1631 83

A GlcNase (exo-beta-D-glucosaminidase) was purified from culture supernatant of Amycolatopsis orientalis subsp. orientalis grown in medium with chitosan. The enzyme hydrolysed the terminal GlcN (glucosamine) residues in oligomers of GlcN with transglycosylation observed at late reaction stages. 1H-NMR spectroscopy revealed that the enzyme is a retaining glycoside hydrolase. The GlcNase also behaved as an exochitosanase against high-molecular-mass chitosan with K(m) and kcat values of 0.16 mg/ml and 2832 min(-1). On the basis of partial amino acid sequences, PCR primers were designed and used to amplify a DNA fragment which then allowed the cloning of the GlcNase gene (csxA) associated with an open reading frame of 1032 residues. The GlcNase has been classified as a member of glycoside hydrolase family 2 (GH2). Sequence alignments identified a group of CsxA-related protein sequences forming a distinct GH2 subfamily. Most of them have been annotated in databases as putative beta-mannosidases. Among these, the SAV1223 protein from Streptomyces avermitilis has been purified following gene cloning and expression in a heterologous host and shown to be a GlcNase with no detectable beta-mannosidase activity. In CsxA and all relatives, a serine-aspartate doublet replaces an asparagine residue and a glutamate residue, which were strictly conserved in previously studied GH2 members with beta-galactosidase, beta-glucuronidase or beta-mannosidase activity and shown to be directly involved in various steps of the catalytic mechanism. Alignments of several other GH2 members allowed the identification of yet another putative subfamily, characterized by a novel, serine-glutamate doublet at these positions.
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PMID:Two exo-beta-D-glucosaminidases/exochitosanases from actinomycetes define a new subfamily within family 2 of glycoside hydrolases. 1631 14

Gene therapy has emerged as a promising strategy for treatment of various diseases. However, widespread implementation is hampered by difficulties in assessing the success of transfection, in particular, the spatial extent of expression in the target tissue and the longevity of expression. Thus, the development of noninvasive reporter techniques based on appropriate molecules and imaging modalities may help to assay gene expression. We have previously demonstrated the ability to detect beta-galactosidase (beta-gal) activity on the basis of 19F NMR chemical shift associated with release of fluorophenyl aglycons from galactopyranoside conjugates. Use of fluoropyridoxol as the aglycon provides a potential less toxic alternative and we now report the design, synthesis, and structural analysis of a series of novel polyglycosylated fluorinated vitamin B6 derivatives as 19F NMR-sensitive aglycons for detection of lacZ gene expression. In particular, we report the activity of 3,alpha4,alpha5-tri-O-(beta-D-galactopyranosyl)-6-fluoropyridoxol 4, 3-O-(beta-D-galactopyranosyl)-alpha4,alpha5-di-O-(beta-D-glucopyranosyl)-6-fluoropyridoxol 12, and 3-O-(beta-D-galactopyranosyl)-alpha4,alpha5-di-O-(alpha-D-mannopyranosyl)-6-fluoropyridoxol 13. Compounds 4, 12, and 13 all show promising characteristics including highly sensitive 19F NMR response to beta-gal activity (Deltadelta=9.0 approximately 9.4 ppm), minimal toxicity for substrate or aglycon, and good water solubility. However, the differential glycosylation of 12 and 13 appears more advantageous for assessing lacZ gene expression in vivo.
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PMID:Synthesis and characterization of novel lacZ gene reporter molecules: detection of beta-galactosidase activity by 19F nuclear magnetic resonance of polyglycosylated fluorinated vitamin B6. 1653 86

Myricitrin, a botanical flavonol glycoside, could be a useful ingredient of functional foods, cosmetics, and medicines because of its high anti-oxidative activity. However, due to its insolubility in water, it has a limited range of use. To improve this solubility, we glycosylated myricitrin by an enzymatic transglycosylate reaction. Myricitrin was galactosylated by beta-galactosidase from Bacillus circulans using lactose as a sugar donor. The reaction product was 480 times more soluble than myricitrin. Four myricitrin galactosides were isolated from the reaction products by column chromatography, and their molecular structures were identified by using ESI-MS, 1H-NMR, 13C-NMR, 1H-1H COSY, 1H-13C HMQC and 1H-13C HMBC analysis. The solubility of these four myricitrin galactosides was more than 3.9 x 10(3) fold that of myricitrin, and each had similar anti-oxidative activity to that of myricitrin.
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PMID:Enzymatic production of highly soluble myricitrin glycosides using beta-galactosidase. 1663 62

2-Fluoro-4-nitrophenol-beta-D-galactopyranoside (OFPNPG) belongs to a novel class of NMR active molecules (fluoroaryl-beta-D-galactopyranosides), which are highly responsive to the action of beta-galactosidase (beta-gal). OFPNPG has a single 19F peak (-55 ppm relative to aqueous sodium trifluoroacetate). Upon cleavage by beta-gal, the pH sensitive aglycone 2-fluoro-4-nitrophenol (OFPNP) is observed at a chemical shift of -59 to -61 ppm. The chemical shift response is sufficient to observe beta-gal activity using chemical shift imaging (CSI). 19F CSI studies of enzyme activity and lacZ gene expression in 9L-glioma and MCF7 breast cancer cells are presented, providing further evidence for the utility of OFPNPG as a gene-reporter molecule for future in vivo studies.
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PMID:Imaging beta-galactosidase activity using 19F chemical shift imaging of LacZ gene-reporter molecule 2-fluoro-4-nitrophenol-beta-D-galactopyranoside. 1691 13

Gene therapy shows promise for treating prostate cancer and has been evaluated in several clinical trials. A major challenge that remains is to establish a method for verifying transgene activity in situ. The lacZ gene encoding beta-galactosidase historically has been the most popular reporter gene for molecular biology. We have designed a 19F NMR approach to reveal lacZ gene expression by assessing beta-galactosidase (beta-gal) activity in vivo. The substrate 2-fluoro-4-nitrophenyl beta-D-galactopyranoside (OFPNPG) is readily hydrolyzed by beta-gal with a corresponding decrease in the 19F-NMR signal from OFPNPG and the appearance of a new signal shifted 4-6 ppm upfield from the aglycone 2-fluoro-4-nitrophenol (OFPNP). We report proof of principle in cultures of PC3 prostate cancer cells using 19F NMR spectroscopy and 19F chemical shift imaging. More importantly, we demonstrate for the first time the ability to differentiate wild-type and lacZ-expressing prostate tumor xenografts in mice using this approach.
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PMID:19F-NMR detection of lacZ gene expression via the enzymic hydrolysis of 2-fluoro-4-nitrophenyl beta-D-galactopyranoside in vivo in PC3 prostate tumor xenografts in the mouse. 1735 Nov 27

A smart contrast agent for magnetic resonance imaging (MRI) can be used to exploit an enzymatic activity specific to the tissue or disease state signified by converting an MRI-inactivated agent to an activated MRI agent. In this study, a beta-galactopyranose-containing gadolinium(III) complex [Gd(DOTA-FPG)(H 2O)] was designed, synthesized, and characterized as being potentially suitable for a bioactivated MRI contrast agent. The (17)O NMR experiments were conducted to estimate the water exchange rate k e x 298 and rotational correlation time tau R 298 . The k ex 298 value of [Gd(DOTA-FPG)(H 2O)] is similar to that of [Gd(DO3A-bz-NO 2)(H 2O)]. The rotational correlation time value of [Gd(DOTA-FPG)(H 2O)] is dramatically longer than that of [Gd(DOTA)(H 2O)] (-) Relaxometric studies show that the percentage change in the T 1 value of [Gd(DOTA-FPG)(H 2O)] decreases dramatically in the presence of beta-galactosidase and human serum albumin. The T(1) change percentage of [Gd(DOTA-FPG)(H 2O)] (60%) is significantly higher than those of Egad and gadolinium(III)-1-(4-(2-(1-(4,7,10-triscarboxymethyl-(1,4,7,10-tetraazacyclododecyl)))-ethylcarbamoyloxymethyl)-2-nitrophenyl)-beta- d-glucopyronuronate. The signal intensity of the MR image for [Gd(DOTA-FPG)(H 2O)] in the presence of human serum albumin and beta-galactosidase (2670 +/- 210) is significantly higher than that of [Gd(DOTA-FPG)(H 2O)] in the sodium phosphate buffer solution (1490 +/- 160). In addition, the MR images show a higher-intensity enhancement in CT26/beta-gal tumor with beta-galactosidase gene expression but not for the CT26 tumor without beta-galactosidase gene expression. We conclude that [Gd(DOTA-FPG)(H 2O)] is a suitable candidate for a bioactivated MRI contrast agent in tracing gene expression.
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PMID:Synthesis and characterization of a new bioactivated paramagnetic gadolinium(III) complex [Gd(DOTA-FPG)(H2O)] for tracing gene expression. 1793 89

It is generally assumed that polyphenols, such as anthocyanins in fruit juice, exist in a free soluble state and are readily available for absorption in the gastro-intestinal tract. In the present study, we have investigated the interaction of polyphenols with soluble carbohydrate polymers, such as pectin and lipid nanovesicles, that are generated during homogenization of the fruit tissue during juice extraction. A commercially available grape juice concentrate contained nearly 25% of polyphenol fraction bound to macromolecules that were nondialyzable. Treatment of dialyzed juice with cellulase, pectinase, and beta-galactosidase did not cause the release of bound polyphenols; however, treatment with triton X-100 caused an increased release of bound polyphenols. The dialyzate contained relatively more -3-O glucosides and -3-O-acetoyl glucosides in comparison to the bound fraction which was enriched in -3-O-coumaroyl glucosides, suggesting qualitative differences in the bound and the free anthocyanin composition. Electron microscopic analysis of the juice fractions revealed the presence of electron-dense nanovesicle-fiber complexes ranging from 10 to 200 nm in diameter. Such complexes were absent in the dialyzate fraction. Cellulase treatment did not change the morphology of the complexes; however, treatment with pectinase and beta-galactosidase disrupted the complexes, releasing vesicular structures, suggestive of the pectin nature of the fibrous matrix. The dialyzed and the dialyzate fractions also showed differences in their 1H NMR and fluorescence spectral characteristics. The dialyzed fraction containing polyphenol-pectin complexes showed no superoxide scavenging capacity, reduced hydroxyl radical scavenging activity, and high 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, indicating potential changes in functionality because of the complex formation.
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PMID:Physico-chemical characteristics of nanovesicle-carbohydrate complexes in grape juice concentrate. 1824 32


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