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)

Physical and chemical properties of the rat liver lysosomes with single Triton WR 1339 overloading were studied during the administration of a detergent to intact rats and those with acute toxic hepatitis. Administration of the latter to intact animals was accompanied by a reduction of the floating density of the particles, solubilization of the lysosome enzymes and by increased fragility of the particles in the hypotonic medium. Lysosomes of the hepatocytes in rats with toxic hepatitis also displayed signs of overloading of the vacuolar apparatus with the preparation administered. The most pronounced solubilization of the lysosomal enzymes beta-galactosidase, acid RNA-ase, cathepsin D--was noted in case of combined action of CCl4 and Triton WR 1339 24, 48, 72 hours and 7 days after the CCl4 poisoning. Possible consequences of overloading of the vacuolar apparatus of the rat hepatocytes are discussed.
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PMID:[Role of vacuolar apparatus overload in lysosomal changes in liver cells in acute toxic hepatitis]. 42 73

Cells of Escherichia coli selectively degrade proteins that have incorporated amino acid analogs. Within 1 hour after exposure of cells to canavanine, 50% of the analog-containing proteins were degraded to acid-soluble form. At the same time, no net loss of canavanine-containing protein occurred from the 100,000 X g supernatant. Instead, most of the proteins containing the analog, unlike normal ones, accumulated in particulate fractions sedimenting at 10,000 X g or 100,000 X g. They were then lost from these fractions concomitant with the degradation of the abnormal proteins. The loss of such proteins from particulate fractions accounted for all of the protein degraded to acid-soluble form. Similar observations were obtained after incorporation of other analogs or puromycin. The 10,000 X g pellets correspond to amorphous dense intracellular granules visible in electron micrographs of cells exposed to canavanine. Upon removal of the analog, these granules disappeared, simultaneously with the degradation of the analog-containing proteins. These pellets do not resemble a degradative organelle, like the lysosome; they are not osmotically sensitive, do not exclude inulin, are not enclosed by a membrane, and do not show autolytic activity. The proteins in the granules could be solubilized by sodium dodecyl sulfate but not by Triton, NaC1, dithiothreitol, RNase, DNase, or phospholipase. The proteins extracted from the pellet with sodium dodecyl sulfate tend to become particulate again upon removal of this detergent. Incorporation of canavanine caused a normally soluble polypeptide, the monomer of beta-galactosidase, to be inactive and found in the sedimentable fraction. These findings suggest that (a) the presence of amino acid analogs in proteins can make them less soluble, and (b) the inclusions are formed by the spontaneous precipitation of abnormal proteins rather than by an active granule-forming process.
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PMID:Degradation of abnormal proteins in Escherichia coli. Formation of protein inclusions in cells exposed to amino acid analogs. 108 51

Various non-ionic surfactants affect the SOS-inducing potency (SOSIP) of the model genotoxin, 4-nitroquinoline-1-oxide, in Escherichia coli PQ37 to varying degrees, as measured by an automated version of the SOS chromotest. While there is little effect on the SOSIP value and other test parameters from Tween 20 and 80 and, with some reservation, Triton X305 and Tyloxapol, over the critical micelle concentration range, the SOSIP value increases in the presence of comparable concentrations of Triton X15, 45 and 100. A possible dependence of the tester strain's beta-galactosidase production and its growth inhibition on the HLB of the non-ionic surfactants added is discussed.
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PMID:The effect of non-ionic surfactants on the SOS-inducing potency of 4-nitroquinoline-1-oxide in Escherichia coli PQ37. 212 82

Plasmid pCMS1 was isolated from Pseudomonas diminuta MG, a strain which constitutively hydrolyzes a broad spectrum of organophosphorus compounds. The native plasmid was restricted with PstI, and individual DNA fragments were subcloned into pBR322. A recombinant plasmid transformed into Escherichia coli possessed weak hydrolytic activity, and Southern blotting with the native plasmid DNA verified that the DNA sequence originated from pCMS1. When the cloned 1.3-kilobase fragment was placed behind the lacZ' promoter of M13mp10 and retransformed into E. coli, clear-plaque isolates with correctly sized inserts exhibited isopropyl-beta-D-thiogalactopyranoside-inducible whole-cell activity. Sequence determination of the M13 constructions identified an open reading frame of 975 bases preceded by a putative ribosome-binding site appropriately positioned upstream of the first ATG codon in the open reading frame. An intragenic fusion of the opd gene with the lacZ gene produced a hybrid polypeptide which was purified by beta-galactosidase immunoaffinity chromatography and used to confirm the open reading frame of opd. The gene product, an organophosphorus phosphotriesterase, would have a molecular weight of 35,418 if the presumed start site is correct. Eighty to ninety percent of the enzymatic activity was associated with the pseudomonad membrane fractions. When dissociated by treatment with 0.1% Triton and 1 M NaCl, the enzymatic activity was associated with a molecular weight of approximately 65,000, suggesting that the active enzyme was dimeric.
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PMID:Cloning and sequencing of a plasmid-borne gene (opd) encoding a phosphotriesterase. 283 39

In order to know if the beta-galactosidase of the rat epididymal fluid, as other secreted acid hydrolases, carries a marker in its molecule, we studied the binding of this enzyme to cellular membranes of the epididymal tissue. The binding, like that mediated by the phosphomannosyl receptor, was saturable, did not require calcium, had a Kd in the nM range and was inhibited by phosphatase or metaperiodate treatment of the enzyme. However fructose 6-phosphate derivates were more effective competitive inhibitors than mannose 6-phosphate. The binding capacity of the membranes were extractable with Triton X-100 and incorporable into liposomes. Trypsin inhibited the binding capacity of Triton extracts but it did not affect the affinity of intact cellular membranes for beta-galactosidase. The results suggest that a phosphorylated carbohydrate of the enzyme is bound by a recognizing site of the cellular membranes different from the phosphomannosyl receptor.
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PMID:beta-Galactosidase from rat epididymal fluid is bound by a recognition site attached to membranes of the epididymis different from the phosphomannosyl receptor. 303 84

Homogenates of Giardia lamblia trophozoites exhibited the following hydrolase activities: acid phosphatase (EC 3.1.3.2), proteinase (EC 3.1.4) with urea-denatured hemoglobin and N-benzoyl-DL-arginine-2-naphthylamide as substrates, deoxyribonuclease (EC 3.1.4.5), and ribonuclease (EC 2.7.7.16). beta-N-Acetylglucosaminidase (EC 3.2.1.30), beta-galactosidase (EC 3.2.1.23), beta-glucuronidase (EC 3.2.1.31), alpha-D-glucosidase (EC 3.2.1.20), beta-D-glucosidase (EC 3.2.1.21), and beta-D-xylosidase (EC 3.2.1.37) activities were below the level of detection. Differential and isopycnic centrifugation of homogenates demonstrated that giardial hydrolases were localized in a single-particle population sedimenting at 7200g for 30 min. The particles had a buoyant density in sucrose of 1.15 and exhibited latency. Latency was completely destroyed by Triton X-100 or 15 cycles of freezing and thawing. After centrifugation of Triton- or freeze-thaw-treated particle fractions, the hydrolase activities, though no longer latent, were still sedimentable suggesting tight binding to the organelle membrane. Latency was destroyed simultaneously for all hydrolases, in direct proportion to the amount of Triton added to a particle preparation or to the number of times a particle preparation was subjected to freezing and thawing. These results support the suggestion that the hydrolases of G. lamblia trophozoites are localized in a single-particle population of lysosome-like organelles.
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PMID:Giardia lamblia: localization of hydrolase activities in lysosome-like organelles of trophozoites. 327 50

Injection of Triton WR 1339 into Wistar rats caused a marked increase in contents of free and ester-bound cholesterol, triglycerides, phospholipids and free fatty acids in tissues and a decrease in the activity of lecithin: cholesterol acyltransferase in blood. An increase in concentration of cholesterol esters in tissues was due to a decrease in activity of lysosomal cholesteryl esterase in vivo and in vitro and to an increase in non-sedimentable activities of acid phosphatase, beta-galactosidase and cholesteryl esterase. The decrease in proteolytic degradation of cholesterol esters was accompanied by an increase in the activity of tissue cytoplasmic cholesteryl esterase and by a decrease in activity of acyl-CoA: cholesterol O-acyltransferase in liver tissue.
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PMID:[Activity of cholesterol metabolism enzymes and lipid levels in the rat liver, aorta, adrenals and serum after exposure to triton WR 1339]. 372 78

The activation of sphingomyelinase, galactosyl- and lactosylceramide beta-galactosidases, GM1, beta-galactosidase, cerebroside sulphate sulphatase, trihexosylceramide alpha-galactosidase and globoside beta-hexosaminidase by a number of bile salts was studied. Most of the salts examined, except glycolithocholate and deoxycholate, were effective activators of enzyme activity. Pure, but not crude, taurocholate elicited poor trihexosylceramide alpha-galactosidase and cerebroside sulphate sulphatase activities. The bile salt activation was often dependent on a number of parameters including the bile salt concentraion, pH, protein to bile salt ratio, and the nature of the enzyme preparation. In the absence of bile salts, Triton X-100 induced little activity of any of the hydrolases except sphingomyelinase; in their presence however, Triton either promoted or inhibited the activation depending on the enzyme. Our data suggest that bile salt structure is an important factor in determining the degree of activation of individual hydrolases and that this may be due to intramicellar lipid substrate/bile salt interactions, which either facilitate or inhibit the corresponding enzyme reaction.
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PMID:The bile salt activation of leucocyte sphingolipid hydrolase activity and the modifying effects of triton X-100. 610 84

The properties and bile salt specificities of galactosylceramide and lactosylceramide beta-galactosidase activities (GC and LC-beta-galactosidases) of human leucocytes and fibroblasts were compared. A number of differences were observed. Under the standard assay conditions the former activity was more sensitive to Zn2+ and Triton-X100. Glycocholate and cholate were more active stimulators of the GC-beta-galactosidase than the more frequently used taurocholate which was the most effective stimulator of LC-beta-galactosidase activity. It is postulated that some of the apparent differences in the properties of GC- and LC-beta-galactosidase activities may be attributed to the different micellar properties of the lipid substrates. Experiments with fibroblasts from patients with Krabbe's disease confirmed an almost total absence of GC-beta-galactosidase whichever bile acid was employed. Residual LC-beta-galactosidase activity detected in these cells was much higher ranging from 13% of the lowest measured value when measured with taurocholate to approximately normal values with glycocholate. Fibroblasts obtained from patients with GM1-gangliosidosis displayed close to normal GC and LC-beta-galactosidase activity under our experimental conditions. The data suggest that diagnoses of Krabbe's disease should be performed with galactosylceramide rather than lactosylceramide as substrate.
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PMID:A comparison of the properties and bile salt specificities of galactosylceramide and lactosyl ceramide beta-galactosidase activities in human leucocytes and fibroblasts. 676 28

Leukocytes were isolated from 14 patients (7 males and 7 females ) with Gaucher disease of the Norrbottnian type (Type 3), 32 obligate heterozygotes (16 males and 16 females) for this disease and 20 controls (10 males and 10 females). After collection, the cells were transported in dry ice to the laboratory, where they were assayed. The assays were repeated after the cells had been stored for 12 months. beta-Glucosidase activity was assayed with D-[glucose-U-14C]glucosylceramide at pH 5.8 with Cutscum-Na-cholate as a detergent and 4-methylumbelliferyl-beta-glucoside at pH 4.1 with Triton-Na-taurocholate as a detergent. The activities of two marker enzymes, 4-methylumbelliferyl-beta-galactosidase and N-acetyl-beta-glucosaminidase, were assayed in aliquots of the same leukocyte samples. The activity of beta-galactosidase remained constant during storage, N-acetyl-beta-glucosaminidase increased, while beta-glucosidase decreased as assayed with the natural as well as with the artificial substrate. beta-Glucosidase activity was significantly lower in the female than in male controls and heterozygotes. When assayed with natural substrate beta-glucosidase activity in leukocytes from the male patients was 6--12% of the control mean value and 10--15% in those from the female patients. The corresponding figures found when the artificial substrate was used were 15--30% and 22--45%. The values for the heterozygotes were respectively 42--68% and 34--79% with the natural substrate, and 33--82% and 51--109% with the artificial substrate. No correlation was found between the age of the patient and the beta-glucosidase activity.
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PMID:Assay of the beta-glucosidase activity with natural labelled and artificial substrates in leukocytes from homozygotes and heterozygotes with the Norrbottnian type (Type 3) of Gaucher disease. 677 5


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