Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synergistic effects of dexamethasone (DEX) and thyroxine (T4) on the postnatal maturation of the 13-d-old rodent small intestine has been studied. Previous studies have shown that hydrocortisone and T4 produced a synergistic response in enzyme maturation. However, T4 elevates corticosteroid-binding globulin, which reduces the clearance of hydrocortisone. Thus, the apparent synergy between T4 and hydrocortisone may have been due to increased glucocorticoid availability. DEX, which does not bind to corticosteroid-binding globulin, was given (d8-12) at 25 pmol (i.e. 0.01 micrograms)/g body wt/d as established by a dose-response study in which this dose of DEX induced one third the maximum response in sucrase activity. In this way, synergy with T4 (130 pmol/g body wt/d, i.e. 0.1 micrograms/g body wt/d, d 5-12) could still be observed. Glucoamylase, lactase, acid beta-galactosidase, alkaline phosphatase, and sucrase activities were determined in two regions of the small intestine. Overall, the results for the two hormones administered alone showed intestinal maturation to be not significantly affected in the T4 group and partially stimulated in the DEX group. When combined, DEX + T4 synergistically increased jejunal sucrase, ileal glucoamylase, and duodenal alkaline phosphatase, and lowered ileal acid beta-galactosidase. The striking exceptions to the general pattern were two brush border enzymes that normally decline during intestinal maturation, namely ileal alkaline phosphatase and jejunal and ileal lactase. For these enzymes, DEX alone did not elicit precocious maturation, and there was no evidence for a synergistic interaction of these two hormones. Serum corticosterone concentrations also were measured. When corticosterone concentrations were compared with enzyme activity, no correlation was found.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Synergistic effects of thyroxine and dexamethasone on enzyme ontogeny in rat small intestine. 140 67

The regulation of Shiga toxin expression in a clinical isolate of S. dysenteriae 1 by the Fe-Fur (Iron-ferric uptake regulatory protein) repressor complex was investigated. The presence of an endogenous Fur repressor protein capable of binding to either a Fur binding consensus sequence or the regulatory region of SLT-1A was determined in toxinogenic strains of S. dysenteriae. Plasmid constructs bearing Fur binding sites fused to readily assayable reporter genes were used. Plasmid pSC27.1 contains a 21 bp synthetic oligonucleotide Fur protein binding consensus sequence located upstream to the gene for beta-galactosidase. Plasmid pSC105 contains the regulatory sequences of Shiga-like toxin-1A located upstream to the gene for alkaline phosphatase. In an analogous fashion to Shiga toxin regulation in S. dysenteriae 1, transformants bearing either pSC27.1 or pSC105 plasmid DNA were repressed in gene product expression when grown in minimal medium supplemented with iron. Conversely, transformants were de-repressed when grown under iron limiting conditions. These data suggest the presence of Fe-Fur mediated regulation of toxinogenesis in clinical isolates of S. dysenteriae.
 ...
PMID:Regulation of the SLT-1A toxin operon by a ferric uptake regulatory protein in toxinogenic strains of Shigella dysenteriae type 1. 143 Sep 67

beta-galactosidase and alkaline phosphatase activities of Escherichia coli strain PQ37 carrying the fusion gene of sulA and lacZ treated with different types of ionizing radiation were examined. The induction factor (ratio of beta-galactosidase to alkaline phosphatase activity), reflecting the SOS-induction potency, increases significantly with radiation dose. Maximum effectiveness to induce SOS-response has been found for deuterium and helium ions in comparison to gamma-rays, carbon or krypton ions. Increased energy of helium ions leads to greater SOS-induction potency of radiation.
 ...
PMID:Induction of SOS repair by ionizing radiation. Results from experiments at accelerators. 143 82

The a subunit is a membrane component of the F1F0-ATP synthase from Escherichia coli. Regions of a which appear important for membrane insertion or F0 assembly have been identified by analysis of both deletion mutants and fusion proteins which link the mutant a subunits to alkaline phosphatase. This analysis suggests the hydrophilic, amino-terminal domain of a is required for proper membrane targeting and/or insertion of the nascent polypeptide. In addition, the subcellular fractionation of four different a subunit-beta-galactosidase fusion proteins suggests this domain is localized to the periplasm, in agreement with a proposed topological model of the protein (Lewis, M.J., Chang, J.A., and Simoni, R.D. (1990) J. Biol. Chem. 265, 10541-10550). Deletions within the next three putative loops of a appear to have no significant effect on membrane targeting or insertion. Rather, they seem to interfere with the subsequent assembly of a functional enzyme.
 ...
PMID:Deletions in hydrophilic domains of subunit a from the Escherichia coli F1F0-ATP synthase interfere with membrane insertion or F0 assembly. 153 41

A direct, double- and triple-staining immunoenzymatic method detected and differentiated sporozoites by color in Anopheles stephensi salivary glands and in mixed sporozoite slide preparations. A double-staining method used beta-galactosidase- and alkaline phosphatase-labeled monoclonal antibodies to the circumsporozoite (CS) proteins of Plasmodium berghei and P. falciparum in mosquito salivary glands. The CS proteins were distinguished clearly by the blue-green and red substrate products of beta-galactosidase and alkaline phosphatase, respectively. A triple-staining method differentiated by color among a mixture of P. falciparum and two strains of P. vivax sporozoites. Monoclonal antibodies to the CS proteins conjugated to beta-galactosidase (P. falciparum), alkaline phosphatase (P. vivax variant), and horseradish peroxidase (P. vivax predominant) readily color differentiated sporozoites by the blue-green, purple-blue, and orange-brown substrate products, respectively. This assay may have potential use in malaria transmission studies, genetic crosses of variant strains of plasmodia to determine assortment of CS antigen alleles, and as a technique to determine the fate of the CS antigen in infected mosquitoes.
 ...
PMID:Immunoenzymatic labeling of multiple plasmodial salivary gland sporozoites in a single test. 155 71

A 7.2 kb Bg/II restriction fragment, which increases the production of several extracellular enzymes, including alkaline phosphatase, amylase, protease, lipase and beta-galactosidase, was cloned in Streptomyces lividans from the DNA of S. griseus ATCC 10137. This gene (named saf) showed a positive gene dosage effect on production of extracellular enzymes. When the saf gene was introduced into cells in high copy numbers it delayed the formation of pigments and spores in S. lividans and also retarded actinorhodin production in Streptomyces coelicolor. The saf gene hybridized with specific bands in the DNA of several Streptomyces strains tested. A 1 kb fragment containing the saf gene was sequenced and contains an open reading frame (ORF) of 306 nucleotides which encodes a polypeptide of Mr 10,500. This ORF is contained within a fragment of 432 bp which retained activity in Streptomyces. A fragment with promoter activity is present upstream of the saf reading frame. The predicted Saf polypeptide has a strong positive charge, and does not show a typical amino acid composition for a membrane protein, and contains a DNA-binding domain similar to those found in several regulatory proteins.
 ...
PMID:Cloning and characterization of a gene of Streptomyces griseus that increases production of extracellular enzymes in several species of Streptomyces. 170 69

Synthetic peptide-alkaline phosphatase conjugates can be used to detect the epitope specificity of (i) antibody-forming cells in vivo by immunocytochemistry; (ii) of antibody secreting cells in vitro by spot-ELISA; and (iii) antibodies in solution by capture ELISA. The availability of synthetic peptide-enzyme conjugates using detector enzymes other than alkaline phosphatase would offer several important advantages, for example in double staining approaches. This paper reports the production of synthetic peptide-horseradish peroxidase conjugates and synthetic peptide-beta-galactosidase conjugates. A peptide of 21 amino acids (SP 29) was coupled to peroxidase in seven differing molar ratios of peptide over peroxidase, ranging from 1:3.4 to 1:575, using periodate oxidation of the enzyme. SP 29 was coupled to beta-galactosidase in four molar ratios ranging from 1.25 to 10, using glutaraldehyde pre-activation of the enzyme. The enzyme activity of the different conjugates was determined, the conjugates were tested in direct capture-ELISA with peptide-specific monoclonal antibodies, and the conjugates were tested in immunocytochemistry to detect peptide-specific B cells. The results show that the conjugates perform best if the peptide is coupled to the enzyme at relatively low molar ratios (1-30). The availability of these new peptide-enzyme conjugates broadens the applicability of synthetic peptides for detection purposes in several assay systems.
 ...
PMID:Synthetic peptide conjugates with horseradish peroxidase and beta-galactosidase for use in epitope-specific immunocytochemistry and ELISA. 172 93

The structure of the linkage region of chondroitin sulfate chains attached to the hybrid proteoglycans of the Engelbreth-Holm-Swarm mouse tumor was investigated. The peptidoglycan fraction which contains oversulfated chondroitin sulfate rich in the GlcA beta 1-3GalNAc-4,6-diO-sulfate unit and undersulfated heparan sulfate rich in GlcA beta 1-4GlcNAc and GlcA beta 1-4GlcN-2N-sulfate units was isolated after exhaustive protease digestion of the acetone powder of the tumor tissue, (GlcA, glucuronic acid; GalNAc, 2-deoxy-2-N-acetylamino-D-galactose). Glycosaminoglycans were released by beta-elimination using NaB3H4 and digested with chondroitinase ABC. The linkage region fraction was separated from heparan sulfate by gel filtration and fractionated by HPLC on an amine-bound silica column. Six radiolabeled compounds (L1-L6) were obtained and structurally analyzed by cochromatography with authentic hexasaccharide alditols recently isolated by us from the linkage region, and by digestion using chondroitinase ACII, alkaline phosphatase and beta-galactosidase in conjugation with HPLC. These compounds shared the conventional hexasaccharide backbone structure: delta GlcA beta 1-3GalNAc beta 1-4GlcA beta 1-3Gal beta 1-3Gal beta 1-4Xyl-ol, (delta GlcA, delta 4.5-GlcA or D-gluco-4-enepyranosyluronic acid). L1 was not sulfated or phosphorylated. L2 and L4 were monosulfated at C-6 and C-4 of the GalNAc residue, respectively. Upon alkaline phosphatase digestion, L3, L5 and L6 were converted to L1, L2 and L4, respectively. Analysis of the periodate oxidation products indicated that the phosphate group in L3, L5 and L6 is located at C-2 of Xyl-ol. These results suggest that Xyl-2-O-phosphate is associated with both 4-O-sulfated and 6-O-sulfated GalNAc units and does not directly determine the sulfation pattern of chondroitin sulfate.
 ...
PMID:The phosphorylated and/or sulfated structure of the carbohydrate-protein-linkage region isolated from chondroitin sulfate in the hybrid proteoglycans of Engelbreth-Holm-Swarm mouse tumor. 174 Jan 53

Secretion of haemolysin (HlyA) is secA independent, but depends upon two accessory membrane proteins, HlyB and HlyD, encoded by the hly determinant. A fourth (cytoplasmic) protein, HlyC, is required to activate HlyA post-translationally, but has no role in export. Deletion studies have previously shown that the HlyA molecule contains a targeting signal close to the C-terminus which specifically directs its secretion to the medium. This targeting signal has been variously located within the terminal 27, 53, 60 or 113 amino acids. In this paper, we have sought to confirm the presence of a C-terminal targeting signal and to analyse the specificity of the Hly transport system through fusion of C-terminal fragments of HlyA to heterologous polypeptides. A C-terminal fragment (23 kDa) of HlyA, when fused at the C-terminus, efficiently promoted the secretion of the eukaryotic protein prochymosin (PCM) to the medium via HlyB and HlyD. This result is in contrast to previous findings that prochymosin, preceded by the alkaline phosphatase signal sequence, cannot be translocated across the Escherichia coli inner membrane. The HlyA targeting domain was also used to secrete to the medium varying portions of chloramphenicol acetyltransferase (CAT) and 98 per cent of the beta-galactosidase (LacZ) molecule (both E. coli cytoplasmic proteins). In the case of the PCM and CAT fusions the efficiency of secretion was reduced as the proportion of the PCM and CAT molecule increased. This result is consistent with inhibition of secretion through the irreversible folding of the larger passenger protein fragments, or the occlusion of the HlyA targeting signal by upstream sequences. Analysis of the nature of the C-terminal domain promoting secretion of prochymosin, demonstrated that shortening the signal domain from 218 to 113 amino acids significantly reduced the efficiency of secretion. This result may also reflect the importance of maintaining an independently folded signal motif well separated from a passenger domain.
 ...
PMID:Analysis of the haemolysin transport process through the secretion from Escherichia coli of PCM, CAT or beta-galactosidase fused to the Hly C-terminal signal domain. 179 66

One hundred and one young-adult female Sprague-Dawley rats were acclimatized to metabolic cages for 2 days. After that time 24-hour urine was collected at a constant cooling temperature of 0-4 degrees C. After gel filtration the enzyme activities were determined, and the resulting values were used to calculate 24-hour excretions. The following reference ranges (2.5 and 97.5 percentiles) were determined (in mU/24 h): lactate dehydrogenase 43-181; phosphohexoseisomerase 45-1445; glutathione-S-transferase 1-299; alkaline phosphatase 27-1239; leucine arylamidase 72-377; gamma-glutamyltransferase 1334-9188; arylsulphatase A 59-309; beta-galactosidase 76-305; beta-glucuronidase 20-2756; beta-N-acetyl-D-glucosaminidase 66-491; glutamate dehydrogenase 7-711. There was a significant (though not very high) correlation with diuresis for the lysosomal enzymes beta-N-acetyl-D-glucosaminidase, arylsulphatase A and beta-galactosidase, and for glutamate dehydrogenase, lactate dehydrogenase, phosphohexoseisomerase and alkaline phosphatase. The relation to creatinine excretion was markedly close for the lysosomal enzymes beta-N-acetyl-D-glucosaminidase, arylsulphatase A and beta-galactosidase (r = 0.71-0.83), as well as for alkaline phosphatase, leucine arylamidase and gamma-glutamyltransferase. There was a relatively high correlation between the excretion of beta-N-acetyl-D-glucosaminidase, arylsulphatase A and beta-galactosidase among themselves (r = 0.63-0.81) as well as between leucine arylamidase and gamma-glutamyltransferase (r = 0.75).
 ...
PMID:Excretion of urinary enzymes in female Sprague-Dawley rats in relation to cellular compartment, creatinine excretion and diuresis. 179 3


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>