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

---

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

High-performance liquid chromatography with on-line electrospray ionization mass spectrometry (ESI-LC/MS) was investigated for the analysis of carbohydrate heterogeneity using RNase B as a model glycoprotein. Oligosaccharides released from RNase B with endoglycosidase H were reduced and separated on a graphitized carbon column (GCC). GCC-HPLC/MS in the positive-ion mode was successful in the identification of one Man5GlcNAc, three Man6GlcNAc, three Man7GlcNAc, three Man8GlcNAc, one Man9GlcNAc, and an oligosaccharide having six hexose units (Hex) and two N-acetylhexosamine units (HexNAc). The branch structures of the three Man7GlcNAc isomers were determined by liquid chromatography with tandem mass spectrometry (LC/MS/MS). LC/MS/MS analysis was shown to be useful for the detection and identification of a trace amount of Hex6HexNAc2 alditol as a hybrid-type oligosaccharide. Its structure was confirmed by the combination of LC/MS with enzymatic digestion using beta-galactosidase and N-acetyl-beta-glucosaminidase. The relative quantities of high-mannose-type oligosaccharides in RNase B detected by ESI-LC/MS are in reasonable agreement with those by UV, high-pH anion-exchange chromatography with pulsed amperometric detection, fluorophore-assisted carbohydrate electrophoresis. Our results indicate that LC/MS and LC/MS/MS can be utilized to elucidate the distribution of oligosaccharides and their structures, which differ in molecular weight, sugar sequence, and branch structure.
...
PMID:Analysis of carbohydrate heterogeneity in a glycoprotein using liquid chromatography/mass spectrometry and liquid chromatography with tandem mass spectrometry. 1022 1

Three major inhibitors of the NF-kappaB/Rel family of transcription factors, IkappaBalpha, IkappaBbeta, and IkappaBepsilon, have been described. To examine the in vivo role of the most recently discovered member of the IkappaB family, IkappaBepsilon, we generated a null allele of the murine IkappaBepsilon gene by replacement of all coding sequences with nlslacZ. Unlike IkappaBalpha nullizygous mice, mice lacking IkappaBepsilon are viable, fertile, and indistinguishable from wild-type animals in appearance and histology. Analysis of beta-galactosidase expression pattern revealed that IkappaBepsilon is mainly expressed in T cells in the thymus, spleen, and lymph nodes. Flow cytometric analysis of immune cell populations from the bone marrow, thymus, spleen, and lymph nodes did not show any specific differences between the wild-type and the mutant mice, with the exception of a reproducible 50% reduction of the CD44-CD25+ T cell subspecies. The IkappaBepsilon-null mice present constitutive up-regulation of IgM and IgG1 Ig isotypes together with a further increased synthesis of these two isotypes after immunization against T cell-dependent or independent Ags. The failure of observable augmentation of constitutive nuclear NF-kappaB/Rel-binding activity is probably due to compensatory mechanisms involving IkappaBalpha and IkappaBbeta, which are up-regulated in several organs. RNase-mapping analysis indicated that IL-1alpha, IL-1beta, IL-1Ra, and IL-6 mRNA levels are constitutively elevated in thioglycolate-elicited IkappaBepsilon-null macrophages in contrast to GM-CSF, G-CSF, and IFN-gamma, which remain undetectable.
...
PMID:IkappaBepsilon-deficient mice: reduction of one T cell precursor subspecies and enhanced Ig isotype switching and cytokine synthesis. 1057 Feb 87

To study the efficiency of RNA-based vaccines, RNA coding for the model antigen beta-galactosidase (beta-gal) was transcribed in vitro from a lacZ gene flanked by stabilizing Xenopus laevis beta-globin 5' and 3' sequences and was protected from RNase degradation by condensation with the polycationic peptide protamine. The liposome-encapsulated condensed RNA-peptide complex, the condensed RNA-peptide complex without liposome or naked, unprotected RNA, was injected into BALB/c (H-2(d)) mice. All preparations led to protein expression in the local tissue, activation of L(d)-restricted specific cytotoxic T lymphocytes (CTL) and production of IgG antibodies reactive against beta-gal. RNA-triggered CTL were as efficient in the lysis of lacZ-transfected target cells as CTL triggered by a lacZ-DNA eukaryotic expression vector. Immunization with RNA transcribed from a cDNA library from the beta-gal-expressing cell line P13.1 again led to beta-gal-specific CTL and IgG induction. Thus, both naked and protected RNA can be used to elicit a specific immune response in vivo, whereby the protected RNA is stable in vitro for a longer period of time. RNA vaccines can be produced in high amounts and have the same major advantages as DNA vaccines but lack the potentially harmful effect of DNA integration into the genome.
...
PMID:In vivo application of RNA leads to induction of specific cytotoxic T lymphocytes and antibodies. 1060 21

Although the primary function of U1 snRNA is to define the 5' donor site of an intron, it can also block the accumulation of a specific RNA transcript when it binds to a donor sequence within its terminal exon. This work was initiated to investigate if this property of U1 snRNA could be exploited as an effective method for inactivating any target gene. The initial 10-bp segment of U1 snRNA, which is complementary to the 5' donor sequence, was modified to recognize various target mRNAs (chloramphenicol acetyltransferase [CAT], beta-galactosidase, or green fluorescent protein [GFP]). Transient cotransfection of reporter genes and appropriate U1 antitarget vectors resulted in >90% reduction of transgene expression. Numerous sites within the CAT transcript were suitable for targeting. The inhibitory effect of the U1 antitarget vector is directly related to the hybrid formed between the U1 vector and target transcripts and is dependent on an intact 70,000-molecular-weight binding domain within the U1 gene. The effect is long lasting when the target (CAT or GFP) and U1 antitarget construct are inserted into fibroblasts by stable transfection. Clonal cell lines derived from stable transfection with a pOB4GFP target construct and subsequently stably transfected with the U1 anti-GFP construct were selected. The degree to which GFP fluorescence was inhibited by U1 anti-GFP in the various clonal cell lines was assessed by fluorescence-activated cell sorter analysis. RNA analysis demonstrated reduction of the GFP mRNA in the nuclear and cytoplasmic compartment and proper 3' cleavage of the GFP residual transcript. An RNase protection strategy demonstrated that the transfected U1 antitarget RNA level varied between 1 to 8% of the endogenous U1 snRNA level. U1 antitarget vectors were demonstrated to have potential as effective inhibitors of gene expression in intact cells.
...
PMID:Reduction of target gene expression by a modified U1 snRNA. 1128 60

We constructed two aptamers, each of which contains a 7-nt-long loop complementary to the anticodon loop of a suppressor tRNA. One of these aptamers can form a stable bimolecular complex with the suppressor tRNA in vitro and protects the 7 nt in the suppressor's anticodon loop from RNase S1. An Escherichia coli strain, carrying an amber mutation in the lac Z gene, produces beta-galactosidase only if the suppressor is present; the aptamer's coexpression in the cell inhibits the activity of the suppressor tRNA. Moreover, in E. coli extract, the aptamer partially inhibits the read-through of the stop codon on the part of the suppressor tRNA. These results point to a novel strategy that need not be limited to the suppressor tRNA. By constructing appropriate inducible aptamers, it may well be possible to effectively control translation in vivo.
...
PMID:Trans-acting RNA inhibits tRNA suppressor activity in vivo. 1216 45

Xmi-er1 is a fibroblast growth factor regulated immediate-early gene that is activated during mesoderm induction in Xenopus embryonic explants. This gene encodes a nuclear protein with potent transcriptional regulator activity and overexpression of XMI-ER1 in Xenopus embryos inhibits mesoderm induction and leads to truncations along the anteroposterior axis. We showed previously that XMI-ER1 is retained in the cytoplasm during cleavage stages and only begins to appear in the nucleus at mid-blastula. Such developmentally regulated nuclear translocation may represent an important mechanism for regulating XMI-ER1 activity in the early embryo. Here, we investigate different mechanisms that might control nuclear translocation of XMI-ER1. Using alpha-amanitin to inhibit transcription, we show that nuclear localization is not dependent on zygotic transcription. Nor is it the result of a developmentally regulated import pathway, as the XMI-ER1 nuclear localization signal (NLS) fused to beta-galactosidase (betagal) was able to direct nuclear translocation prior to mid-blastula. Fusion of an additional, heterologous NLS to the N-terminus of XMI-ER1 was not sufficient to overcome cytoplasmic retention, indicating that retention does not involve NLS masking, but rather binding to a cytoplasmic anchor. The anchoring molecule is not an RNA, as microinjection of RNase A did not affect the timing of nuclear translocation. Western blot analysis using antibodies that recognize phosphorylated residues revealed that, while XMI-ER1 is not itself phosphorylated, it is associated with two differentially phosphorylated proteins, suggesting that the anchoring mechanism may involve interaction with a cytoplasmic protein(s). A series of XMI-ER1 deletion mutants was utilized to map the putative retention domain. Our analysis revealed that amino acids 144-175, containing the fourth acidic stretch of the acidic activation domain, are required for retention. These results suggest that XMI-ER1 is retained in the cytoplasm of the early embryo by interaction of the region containing amino acids 144-175 with a cytoplasmic anchor.
...
PMID:Developmentally regulated cytoplasmic retention of the transcription factor XMI-ER1 requires sequence in the acidic activation domain. 1547 90

Pairs of very closely related Escherichia coli strains were prepared, one having the wild-type allele for ribonuclease III, an enzyme which specifically degrades double-stranded RNA, and the other having a mutant RNase III allele. Growth and phage plating efficiency were compared in these strains. The RNase III+ strains grow better than the RNase III- strains and plate T7 and lambda phage better, but T4 plates with the same efficiency on both strains. On the other hand, the half lives of newly synthesized RNA as well as of functional beta-galactosidase mRNA are similar in both kind of strains. These two parameters, however, are significantly longer in both strains as compared to the original strain from which they were derived. Also, no difference in the differential induction of beta-galactosidase was observed between such strains. Thus, we have to conclude that either ribonuclease III does not play a significant role in the functioning and stability of newly synthesized mRNA, or that enough enzymatic activity was left, residual RNase III or some other enzyme to deal with double-stranded regions in the message.
...
PMID:Unaltered stability of newly synthesized RNA in strains of Escherichia coli missing a ribonuclease specific for double-stranded RNA. 1609 99

Protein bodies and spherosomes isolated from mature seeds of Sorghum bicolor (Linn.) Moench have measurable activity of acid protease, alpha-glucosidase, beta-glucosidase, beta-galactosidase, phytase, acid pyrophosphatase, p-nitrophenyl phosphatase, and RNase. Protein bodies have largely insoluble activities, and produce soluble protein and soluble amino nitrogen during autolysis. They have the dual function of protein storage and protein catabolism. Spherosomes have considerable amounts of soluble enzymes and autolytically produce soluble amino nitrogen and inorganic phosphate but release little soluble protein. Spherosomes are similar to animal lysosomes but have an additional storage function for protein, phosphorus, and metals. Mature sorghum seed contains the necessary enzymes and substrates to generate two basic metabolites, amino acids and inorganic phosphate.
...
PMID:Acid Hydrolases and Autolytic Properties of Protein Bodies and Spherosomes Isolated from Ungerminated Seeds of Sorghum bicolor (Linn.) Moench. 1665 31

The development of techniques to isolate and purify relatively large quantities of intact vacuoles from mature tissues permits direct biochemical analysis of this ubiquitous mature plant cell organelle. Vacuoles and a fraction enriched in soluble cytoplasmic constituents were quantitatively prepared from Hippeastrum flower petal protoplasts. Vacuolar lysate and soluble cytoplasmic fractions were examined for acid hydrolase activities commonly associated with animal lysosomes, and pH optima were determined. Esterase, protease, carboxypeptidase, beta-galactosidase, alpha-glycosidase and beta-glycosidase, not found in the vacuole lysate fraction, were components of the soluble cytoplasmic fraction. Acid phosphatase, RNase and DNase were present in both fractions. Vacuolar enzyme activities were also examined as a function of flower development from bud through senescent stages. The data obtained are not consistent with the concept that the mature plant cell vacuole functions as a generalized lysosome.
...
PMID:Localization of Acid hydrolases in protoplasts: examination of the proposed lysosomal function of the mature vacuole. 1666 1

In the cotyledon extracts of seedlings of many oil seeds, including soybean, sunflower, cucumber, and peanut, the in vitro lipase activity was too low to account for the observed in vivo lipolysis. The low in vitro lipase activity was due to the presence of lipase inhibitors in the extracts. The inhibitors from soybean were characterized based on their effects on the hydrolysis of trilinolein by corn, pancreatic, and Rhizopus lipases. The inhibitors were not dialyzable and unaltered by RNase and beta-galactosidase treatment. However, they were sensitive to heating and protease digestion. The inhibitory effect of the inhibitors was expressed irrespective of the sequence of the addition of lipase, substrate, and inhibitors to the assay medium. The inhibitory effect was equally expressed when the inhibitors were added either before or after the lipase reaction had been in progress. The inhibitory effect of the inhibitors was independent of the amount of lipase present in the assay, but was dependent on the amount of substrate added. High substrate concentration eliminated totally the inhibitory effect of the inhibitors. Most of the inhibitors were recovered in the soluble fraction in subcellular fractionation. They were present in the 2-4S and not in the 7S, and 11S (storage proteins) protein fraction. There was a gradual decrease of the inhibitors in the cotyledons in the postgerminative growth. We suggest that the inhibitors are proteins which bind to the surface of the substrate micelles. The binding prevents the normal functioning of lipase which acts on the interfacial area between the aqueous medium and the micelle surface.
...
PMID:Inhibitors of lipase activities in soybean and other oil seeds. 1666 73


<< Previous 1 2 3 4 5 6 Next >>

---