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)

Cell transplantation through the intracoronary route has theoretical advantages over direct intramuscular injection in global cell dissemination into the myocardium with less injury. The authors have established a novel experimental model of retrograde intracoronary infusion in the rat by which the feasibility of this infusion for cell transplantation and the dynamics of myoblasts grafted by this route were investigated. After retrograde intracoronary implantation of beta-galactosidase-expressing myoblasts, myoblasts were observed to disseminate to all layers of only the left ventricular free wall, with little myocardial damage, and to differentiate into multinuclear myotubes by day 28. Beta-galactosidase enzyme activity estimated that 31.4% of initially grafted myoblasts existed within the heart at 10 min after implantation. The number slightly increased by day 3, increased to 117.3% at day 7, and reached a plateau of 132.1% at day 14. These data suggest the utility of retrograde intracoronary infusion for selective cell dissemination into the myocardium.
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PMID:Selective cell dissemination into the heart by retrograde intracoronary infusion in the rat. 1502 42

We have analyzed Msx1 expression in the mature mouse brain using in situ hybridization and beta-galactosidase activity in Msx1(nLacZ) mice. The study revealed that Msx1 is strongly expressed in the circumventricular organs, such as the subcommissural organ and choroid plexus, and in some epithelia, such as that of the dorsal, but not the ventral part of the third ventricle. Immunohistochemical analysis revealed that the Msx1-expressing cells of the hippocampus and fimbria are astrocytes, oligodendrocytes or immature oligodendrocytes. In contrast, no co-expression was detected in these structures using several neuronal markers. These results were confirmed, using transmission electron microscopy, by the presence of 5-bromo-3-indolyl-beta-D-galactopyranosideprecipitates in astrocytes and oligodendrocytes in both sites. Moreover, using an anti-glial fibrillary acidic protein antibody (GFAP), our study reveals two populations of astrocytes in the adult hippocampus and other areas, such as the fimbria, namely Msx1+/GFAP+ and Msx1-/GFAP+. Beta-galactosidase activity was also observed in endothelial cells of hippocampal fissure blood vessels. We also observed co-localization of polysialic acid neural cell adhesion molecule, a marker of the polysialylated form of the neural cell adhesion molecule, in Msx1-expressing cells in the fimbria. These cells may be precursors of glial cells and originate from the epithelium of the fimbria. The present study indicates, in the mature mouse brain, that Msx1 may be linked to secretory activity in circumventricular organs, and to glial proliferation and differentiation in the hippocampus and fimbria, and presumably also in other cerebral areas. We suggest that Msx1 could be associated with brain homeostasis and blood-brain barrier function.
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PMID:Msx1 expression in the adult mouse brain: characterization of populations of beta-galactosidase-positive cells in the hippocampus and fimbria. 1531 1

Beta-galactosidase and peroxidase are enzymes reported to have roles in pepper maturation. Fertilizer rate may affect activity of these enzymes in fruit maturing on the plant. Nine pepper cultivars, five non-pungent and four pungent, were fertilized at two rates in field plots in 1997 and 1998 at Lane, OK, USA. Fruit were harvested at mature green, turning, and red color developmental stages, and assayed for beta-galactosidase and peroxidase activity. Overall fruit beta-galactosidase activity increased as fertilizer rate increased, and was highest in red fruit. Fertilizer rate and fruit developmental stage did not affect peroxidase activity in 1997, but peroxidase activity was highest in red fruit in 1998. Enzyme activity appeared to be cultivar dependent, and patterns differed in both years. Activities of both enzymes were higher at the red stage in many of the non-pungent peppers than in pungent peppers. These data suggest that increased fertilizer affects the activity of at least one enzyme in fruit maturing on the plant. Cultural practices affecting enzyme activity may be used to modify concentrations of components in plants that are important for human consumption.
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PMID:Fertilizer rate and beta-galactosidase and peroxidase activity in pepper fruit at different stages and years of harvest. 1536 64

Although glucose is an inexpensive substrate widely used as a carbon source in Escherichia coli recombinant fermentation technology, 10-30% of the carbon supply is wasted by excreting acetate. In addition to the loss of carbon source, the excretion of a weak acid may result in increased energetic demands and hence a decreased yield. Because glucose can enter the cell via several transport systems, isogenic strains defective in one or two of these transport systems were constructed. The effects of changes in the glucose uptake capacity on the in vivo flux distribution to a desired end product (beta-galactosidase) and to acetate were studied. The lack of one of the components (IICB(Glc) protein) of the glucose-phosphoenolpyruvate phosphotransferase system (Glc-PTS) reduced the growth rate significantly. The maintenance of a low-copy plasmid in this strain resulted in further arrest of the growth rate. However, beta-galactosidase production had no effect on growth rate. This strain directed more carbon into biomass and carbon dioxide, and less into acetate. Beta-galactosidase was produced in amounts not significantly different from the wild-type strain from half the amount of glucose. An explanation for the experimental results is given, making use of published results on metabolic regulation.
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PMID:Reducing the glucose uptake rate in Escherichia coli affects growth rate but not protein production. 1575 56

Translating ribosomes can pass through a stretch of messenger RNA without translating and resume protein chain elongation after the bypassed region. We previously investigated the stimulation of bypassing when the codon in the ribosome [corrected] A-site called for an aminoacyl-tRNA species in short supply. Here, we investigate bypassing in unstarved, growing cells. A collection of lacZ bypass reporters was constructed with nearly all the sense codons as the "takeoff site", each with its matched landing site 16 nucleotides downstream in the beta-galactosidase reading frame. Beta-galactosidase [corrected] synthesis in unstarved cells carrying these reporters was found to vary over a large range. The takeoff sites UUU and AGG yielded unusually high enzyme activities, sufficient for protein sequence analysis; in these cases, sequencing (by Edman degradation or by mass spectrometry) confirmed that the synthesis of lacZ protein occurred through the 16 nt bypass from takeoff to landing site. Thus, bypassing occurs spontaneously under normal conditions, and is not limited to the pathology of amino acid starvation. Indirect evidence suggests that most of the lower enzyme activities of the rest of the collection also reflects bypassing. Another collection of reporters was made with [corrected] various triplets in the A-site [corrected] the codon immediately following a UUC [corrected] takeoff triplet. Spontaneous bypassing in representatives of this collection varied roughly inversely with the abundance of the tRNA encoded at the A-site. For two A-site codons tested, introduction of additional copies of the relevant tRNA gene on a second plasmid reduced spontaneous bypassing. We conclude that any pause with the A-site empty stimulates bypassing. From the P-site and A-site effects on bypassing, we estimated the average frequency of ribosome takeoff; from this, we calculate that the probability that a ribosome will succeed in translating the entire lacZ coding sequence is about 0.73, in agreement with earlier, independent estimates.
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PMID:Spontaneous ribosome bypassing in growing cells. 1589 Jan 94

Beta-galactosidase activity was studied as a possible cause of the low milk acidification ability observed in Lactobacillus reuteri NRRL 14171. Enzymatic activity was determined in MRS broth supplemented with either glucose or lactose and milk at the middle and final stage of the exponential phase, as well as at the stationary phase. Results were compared with beta-galactosidase activity in Lactobacillus casei NRRL-B1922, a strain that shows the milk acidification ability. The effects of the types of carbon and nitrogen sources were established by comparison of growth parameters (higher maximum cell concentration and specific growth rate) in broth culture and skim milk supplemented with 2% glucose or 1% casein peptone. In milk, L. reuteri showed higher beta-galactosidase activity in all growth phases compared with L. casei. Greater cell concentration maxima, specific growth rates, and acidification abilities were observed in L. reuteri when it was cultured in milk supplemented with 1% casein peptone compared with non-supplemented milk cultures. Results suggest that the poor milk acidification ability observed in L. reuteri may be more related to a weak proteolytic system than to deficient beta-galactosidase activity.
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PMID:Lactobacillus reuteri beta-galactosidase activity and low milk acidification ability. 1592 Jun 24

Expression of the recombinant protein beta-galactosidase in the Spodoptera frugiperda Sf-9 insect cell line infected by the Autographa californica nuclear polyhedrosis virus expressing beta-galactosidase (AcNPV-betagal) was visualized using confocal scanning laser microscopy with fluorescent staining of both the recombinant protein and the cell nucleus. The average size of the insect cells and the intracellular DNA concentration both increased markedly, respectively reading 3.8- and 2.3-fold the values before infection. The average beta-galactosidase activity began to increase at 20-24 h post infection and finally reached 1.9 x 10(4) units/ml. As the post infection time increased, the stained nucleus images expanded and spread broadly. Beta-galactosidase was first identified by fluorescent staining at 12 h post-infection, filled the cell at 27 h, began to be released at 36 h, and finally spread out of the cell. The locations of the nucleus and expressed beta-galactosidase were identified from computerized tomograms and 3-dimensional images.
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PMID:Visualization of a recombinant gene protein in the baculovirus expression vector system using confocal scanning laser microscopy. 1623 50

Transplantation of hepatic stem cells in utero has been advanced as a potential clinical approach to a variety of diseases, including deficiencies of coagulation factors. Although syngeneic transplantation has met with some success, consideration needs to be given to the potential for transplanted cells to colonize nontarget tissues. Liver cells were harvested from Rosa26 embyros at embryonic age 12.5 days postconception (pc) and transplanted into the peritoneal cavity of syngeneic recipients in utero. Tissues were harvested from tissue recipients at various time points ranging from 1 to 328 days pc, and tissues were stained for beta-galactosidase to identify the existence of cells derived from Rosa26 donors. Beta-galactosidase-positive cells were found in the lung, liver, and brain as early as 20 days pc and through 328 days pc. Positive cells in these tissues existed as islands of cells that were morphologically similar to hepatocytes. In the spleen, individual beta-galactosidase-positive cells of both leukocytic and erythrocytic lineages were present, and suggest that hematopoietic cells were transferred to recipients along with hepatocytes. The lack of an inflammatory response to the beta-galactosidase-positive cells suggests that the donor cells were immunologically tolerated. In summary, the possibility that cells administered in utero may inadvertently colonize nontarget tissues suggests that clinical application of this method will need to be approached with diligence.
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PMID:Tissue distribution of fetal liver cells following in utero transplantation in mice. 1633 51

Protein transduction domains (PTDs) offer an exciting therapeutic opportunity for the treatment of many diseases. An 11-amino acid fragment of human immunodeficiency type 1 (HIV-1) TAT-protein can transduce large, biologically active proteins into mammalian cells; recent evidence has shown an in vivo PTD for the 116 kDa beta-galactosidase protein. However, there is little information on the in vivo distribution of the TAT fusion protein to define the viability of PTDs for human studies. In this study we examined the tissue kinetics and tissue distribution of the PTD-transduced TAT fusion protein in mice. Low (100 microg) or high (500 microg) doses of TAT-beta-galactosidase fusion protein were administrated to mice through four routes (portal vein, i.v., i.p., and oral). Tissues were harvested 15 min, 1h, 6h, 10h, and 24h after treatment. Distribution of beta-galactosidase in various tissues was analysed by in situ staining, enzymatic activity assay, and Western blot analysis. Beta-galactosidase enzyme activity was observed in all tissues (liver, kidney, spleen, lung, bowel, and brain). Beta-galactosidase activity peaked at 15 min in most tissues after portal vein, i.v., and i.p. administration and at 1h after oral dosing in all tissues. Beta-galactosidase activity in the liver at 15 min after portal vein injection (67 milliunits [mU]/mg) was higher than after i.v. (9.8 mU/mg), i.p. (4.4 mU/mg), and oral (0.3 mU/mg) dosing. In situ staining and Western blot results correlated closely with beta-galactosidase enzyme activity assay. The median initial half-life for activity was 2.2h, ranging from 1.2h to 3.4h (coefficient of variation=28.9%). The bioavailability of beta-galactosidase activity after an orally administered PTD was 24%. This study details the kinetics and tissue distribution of delivering of a model TAT fusion protein into the mouse via PTD. These data allow rational selection of delivery route and schedules for therapeutic PTD and will aid the use of TAT fusion protein transduction in the development of protein therapies.
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PMID:The kinetics and tissue distribution of protein transduction in mice. 1637 28

Beta-galactosidase is thought to be involved in fruit softening through cleaving beta(1-->4) galactan bonds in cell wall hemicellulose. To study the relationship between fruit softening and beta-Gal during banana (Musa sp.) fruit ripening, a beta-Gal cDNA fragment, named MA-Gal, has been cloned from banana fruit pulp using RT-PCR in this study. The results of sequence analysis showed that MA-Gal contained 927 bp, encoding a polypeptide of 309 amino acids, the deduced protein was highly homologous to plant beta-galactosidase expressed in fruit ripening. The MA-Gal putative amino acids have five homologous domains (typical eukaryotic beta-Gals have seven domains), contain the GGPIILSQIENEY(F) motif, which is a presumptive catalytic active site conserved in all beta-Gals. Phylogenetic analysis showed that MA-Gal was in plant beta-Gal group I, which was expressed in fruit tissue. The changes in beta-Gal activity and firmness in pulp during three different stages were also assayed. The Northern analysis showed that the MA-Gal transcripts in pulp were detected at low level at preclimacteric stage, while an increasing progression was observed during fruit ripening, and the highest transcript amount was found at the postclimacteric stage. These results suggest that MA-Gal may play a role during banana fruit ripening and softening.
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PMID:Cloning and expression analysis of beta-galactosidase gene related to softening of banana (Musa sp.) fruit. 1695 91


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