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)

Tetrahymena pyriformis were grown in proteose-peptone medium and then washed and incubated in a dilute salt solution for one hour. The cells were then discarded and the lysosomal hydrolases that had been secreted were subjected to DEAE cellulose column chromatography. At least three isoenzymes of acid phosphatase, three of acid protease, and two of beta-N-acetylhexoseaminidase were found, as well as single peaks of alpha-mannosidase, beta-galactosidase, and beta-fucosidase. The latter two activities were not resolved by the DEAE column and could not be separated in a second chromatographic step on CM-cellulose. Cells were also grown under identical conditions and homogenized in 0.25 M sucrose in order to allow comparison of some of the intracellular lysosomal hydrolases with their secreted counterparts. Two lysosomal populations were resolved by sucrose density gradient sedimentation, a heavy lysosomal fraction, contered at a density of about 1.25 gm/cm3, and a light lysosomal fraction, centered at a density of about 1.16 gm/cm3. These two populations differed in that the light lysosomes did not appear to contain significant amounts of beta-fucosidase, beta-galactosidase, or acid protease, whereas all six of the hydrolase activities studied were present in the heavy lysosomes. The light lysosomal peak occurred in cells grown to transition phase, but was markedly reduced in cells from cultures grown to stationary phase. In addition to these two fractions a third very light particle, containing only alpha-mannosidase activity, was detected just inside the gradient. Measurements were made of the effect of heat (10 minutes at 66 degrees) and of a change in pH from 4.5 (standard assay condition) to 6.0 on the three acid phosphatases and two beta-N-acetylhexoseaminidase isoenzymes resolved by DEAE column chromatography of the secreted hydrolases and on these hydrolyases in the heavy and light lysosomal fractions on the sucrose gradient. Use of the thermostability and pH criteria permitted computation of the expected properties of the intralysosomal acid phosphatase and hexoseaminidase activities if these consisted of the respective isoenzymes in the proportions secreted. It was found that neither the intralysosomal acid phosphatase nor the intralysosomal hexoseaminidase had the properties expected if they consisted of the secreted mixture of the respective isoenzymes, indicating that modification of some of these isoenzymes may have occurred during the 1-hour starvation period or after secretion.
...
PMID:Lysosomal hydrolase secretion by Tetrahymena: a comparison of several intralysosomal enzymes with the isoenzymes released into the medium. 1 Mar 11

Platelet-aggregating factor (PAF) was removed from bovine plasma by human platelets fixed with 2% formaldehyde. The degree of adsorption was directly related to the platelet concentration and the length of incubation. Fixed washed platelets (FWP) aggregated with bovine plasma could be deaggregated by 1M KCl, Evans blue, and 8M urea but not by beta-galactosidase. Incubation with 1M KCl eluted some but not all of the PAF, as the deaggregated platelets spontaneously aggregated upon removal of the deaggregating conditions. Also, fixed platelets adsorbed PAF even in the presence of 1M salt or after treatment with Evans blue. Platelet aggregation was not affected by thrombin (20 micron/ml) but was abolished by trypsin at concentrations as low as 4 X 10(-1) microgram/ml. The data suggest that deaggregation is not the result of elution of the loosely bound aggregating factor from the platelet surface, but rather the disruption of noncovalent interplatelet bridging between one or more PAF molecules bound to a specific receptor.
...
PMID:Platelet-aggregating factor and the aggregation of fixed washed platelets. 1 45

The in vitro synthesis of elongation factor (EF)-Tu (tufB), the beta beta' subunits of RNA polymerase, ribosomal proteins L10 and L12 directed by DNA from the transducing phage lambda rifd 18, EF-Tu (tufA), EF-G, and the alpha subunit of RNA polymerase directed by DNA from the transducing phage lambda fus3 has been investigated in a crude and a partially defined protein-synthesizing system. Proteins L10 and L12 are synthesized in the partially defined system almost as well as in the crude system. However, the synthesis of EF-Tu, EF-G, and the alpha and beta beta' subunits of RNA polymerase is far less efficient in the partially defined system. An active fraction that stimulates the synthesis of these latter proteins has been obtained by fractionation of a high-speed supernatant on DEAE-cellulose. Because previous studies showed that this fraction (1 M DEAE salt eluate) contains a protein, called L factor, that stimulates beta-galactosidase synthesis in vitro, L factor was tested for activity. Although L factor stimulates the synthesis of the beta beta' subunits, it has little or no effect on the in vitro synthesis of the other products studied. In the present experiments, the ratio of L12/L10 and of EF-Tu (tufA)/EF-G formed is 4-6. These values are consistent with in vivo results.
...
PMID:DNA-directed in vitro synthesis of proteins involved in bacterial transcription and translation. 16 May 61

1. The elution profiles of eleven acid hydrolases from human liver and plasma were directly compared using a system whereby a single salt gradient was simultaneously applied to two DEAE-cellulose chromatographic columns. 2. Plasma alpha-L-fucosidase, alpha-mannosidase, alpha-galactosidase and alpha-glucosidase isoenzymes were eluted at higher salt concentrations than the corresponding liver isoenzymes whereasbeta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase, exo-1,4-beta-xylosidase and alpha-L-arabinofuranosidase isoenzymes were eluted at lower salt concentrations. The elution profiles of beta-glucuronidase and acid phosphatase weremore complex. 3. After incubation with neuraminidase most plasma hydrolases were eluted at lower salt concentrations, however the elution patterns of beta-glucosidase, beta-xylosidase and acid phosphatase were not altered. 4. Preincubation with neuraminidase had no effect on the elution profiles of six liver hydrolases whereas the major isoenzymes of alpha-mannosidase, beta-galactosidase and alpha-L-arabinofuranosidase were eluted at markedly lower salt concentrations. Liver alpha-fucosidase and alpha-galactosidase were eluted at slightly lower salt concentrations afterincubation with neuraminidase. 5. The results are discussed in relation to thepathogenesis of Mucolipidosis II (I-cell disease), and the synthesis and packaging of lysosomal enzymes.
...
PMID:Effect of neuraminidase on the chromatographic behaviour of eleven acid hydrolases from human liver and plasma. 19 Dec 58

Lucite chambers, applied to antral and proximal duodenal mucosae with blood supply intact, were used to compare ionic flux and the total, labilized activity of several acid hydrolases including cathepsin D, alpha and beta-galactosidase, beta-N-acetyglucosaminidase, arylsulfatase, and acid phosphatase. Insorption of H+ ion by the antrum is increased by the application of aspirin-acid-salt solution, which also stimulates acid hydrolase activity; acute erosions develop very rapidly. On the other hand, H+ ion is much more rapidly removed from chambers applied to the duodenal mucosa, isolated by the chamber from bile and pancreatic secretions. The same aspirin-acid-salt solution reduces net H+ ion loss from the duodenal chamber, depresses levels of the acid hydrolases, and no ulcers develop.
...
PMID:Effect of aspirin on ionic movement and acid hydrolase activity of explants of canine antral and duodenal mucosae. 23 98

Using fresh frozen, freeze-dried or cryostate sections from aldehyde fixed rat tissues 13 diazonium salts were tested as simultaneous coupling reagents for the localization of acid, neutral and alkaline hydrolases with azo indoxyl methods. Hexazotized new fuchsine and/or Fast blue B are the diazonium salts of choice for the demonstration of acid beta-galactosidase, neuraminidase, beta-N-acetylglucosaminidase, acid phosphatase, and non-specific esterase followed by hexazotized p-rosaniline. Fast blue VB, BB and RR and Fast violet B are recommended for the investigation of alkaline phosphatase and lactase, Fast garnet GBC for acid beta-galactosidase, glucosaminidase and lactase. Fast red B, RC, RL and TR and Fast black K can only be employed for lactase studies. The exact concentration of the coupling reagent depends on the activity of the enzyme and the organ imvestigated. On the average 0.01-0.02 ml unstable diazonium salt/ml and 0.3--1 microgram stable diazonium salt/ml are sufficient for the correct localization of these hydrolases. Freeze-dried cryostat sections yield the best results in the demonstration of lactase and alkaline phosphatase independent on the coupling reagent used. Sections from formaldehyde or glutaraldehyde fixed organs are superior for the localization of the other hydrolases; an exception is the investigation of acid beta-galactosidase and glucosaminidase with Fast garnet GBC. Then, excellent results are obtained also with freeze-dried material. Fresh frozen sections are suitable for the localization of lactase with hexazotized new fuchsine or p-rosaniline and of alkaline phosphatase with Fast blue VB and BB or violet B. The total activity of acid, neutral and alkaline hydrolases can be investigated using semipermeable membranes in combination with all unstable and stable diazonium salts of choice. Reliable osmification of the azoindoxyl dye is only possible if hexazotized p-rosaniline is employed for coupling; without further posttreatment all azoindoxyl dyes are extracted by ethanol, isopropanol or xylol. 7 incubation media are given for the demonstration of hydrolases with azoindoxyl methods at the level of light microscopy for routine studies and typical examples for the application of these methods are presented. A modified procedure is described for the freeze-drying of cryostat sections with the Edwards-Pearse tissue dryer EPD3.
...
PMID:[Azoindoxyl methods for the investigation of hydrolases. IV. Suitability of various diazonium salts (author's transl)]. 36 63

The DNA-directed synthesis of beta-galactosidase in Escherichia coli extracts has been investigated in a partially fractionated system. A dependency was obtained for 3',5'-cyclic AMP receptor protein and also for a factor, from the salt wash of ribosomes, that has been purified to near homogeneity. This factor has been identified with a ribosome release factor previously purified from the supernatant fraction by A. Hirashima and A. Kaji [(1972) Biochemistry 11,4037-4044]. In the coupled transcription-translation system this factor stimulates beta-galactosidase synthesis and total protein synthesis 2- to 4-fold. It is thus clear that the ribosome release factor has a physiological function in translation. It may also affect transcription, because it stimulated total RNA synthesis up to 50% in this in vitro system.
...
PMID:DNA-directed synthesis in vitro of beta-galactosidase: requirement for a ribosome release factor. 41 18

GM1-ganglioside hydrolysis by leukocytes and fibroblasts, tissues easily obtainable from patients, was investigated using 3H-labeled GM1 and was found to be at least as active as that reported for any other tissue. Sodium taurocholate was required for the reaction, the crude bile salt at an optimum concentration of 0.4% producing twice as much activity as pure taurocholate at its optimum concentration of 0.8%. Leukocyte GM1-ganglioside beta-galactosidase and 4-MU-beta-gal cleaving activities were similar, 134.5 +/- 23.3 and 179.8 +/- 25.4 nmol/h/mg protein, respectively. In cultured skin fibroblasts and amniotic fluid cells these enzyme activities were 4 to 5 times higher. Homozygotes for GM1-gangliosidosis showed negligible activity while in heterozygotes the leukocyte GM1-cleaving activity was reduced to one-third of control values. In leukocytes from patients with four other sphingolipid storage diseases the activity was either normal (Krabbe's, Tay-Sachs, Metachromatic leukodystrophy) or increased (adult Gaucher's).
...
PMID:GM1-ganglioside beta-galactosidase in leukocytes and cultured fibroblasts. 41 12

1. Shape change, aggregation and secretion of dense-granule constituents in platelets differ in their dependence on cellular energy metabolism. The possibility that such a difference also exists between secretion of dense-granule constituents and acid hydrolases was investigated. 2. Human platelets were incubated with [(14)C]adenine in plasma, and then washed and resuspended in salt solutions. The effects of incubating the cells with antimycin A and 2-deoxyglucose on the concentrations of [(14)C]ATP, ADP, AMP, IMP and inosine plus hypoxanthine and on thrombin-induced secretion of ATP plus ADP and acid hydrolases were studied. The metabolic inhibitors only affected (14)C-labelled nucleotides, whereas thrombin only liberated unlabelled ATP and ADP. 3. The extent of secretion decreased progressively with time during incubation with the metabolic inhibitors. At any time the secretion of acid hydrolases, beta-N-acetylglucosaminidase, beta-glucuronidase and beta-galactosidase was inhibited to a greater extent than secretion of ATP plus ADP (dense-granule secretion). 4. Incubation with the metabolic inhibitors shifted the log (dose)-response relationship to higher thrombin concentrations, and with a greater shift for acid hydrolase secretion than for dense-granule secretion. 5. Antimycin, when present alone, caused a marked decrease in the rate of acid hydrolase secretion, but had no effect on dense-granule secretion. 6. These results further support the view that acid hydrolase secretion and dense-granule secretion are separate processes with different requirements for ATP energy. Acid hydrolase secretion, but not dense-granule secretion, appears to depend on a simultaneous rapid generation of ATP, which can be accomplished by oxidative, but not by glycolytic, ATP production.
...
PMID:Effects of antimycin A and 2-deoxyglucose on secretion in human platelets. Differential inhibition of the secretion of acid hydrolases and adenine nucleotides. 50 92

Tetrahymena were grown in proteose-peptone medium supplemented with glucose, mannose, fructose, galactose, acetate, succinate, or pyruvate and then washed and resuspended in a non-nutrient salt solution and the amounts of 7 acid hydrolases secreted into the medium in a one hour incubation were measured. Cells that had been grown in the presence of glucose secreted about half the amounts of acid phosphatase, beta-N-acetylglucosaminidase and acid protease as did control cells grown in unsupplemented medium. Pyruvate was about as effective as glucose and both were slightly more effective than acetate or fructose. Succinate had little effect. Similar experiments showed that alpha-mannosidase, beta-fucosidase, and beta-galactosidase are secreted into the salt solution and the secretion is reduced by prior growth of the cells in medium supplemented with glucose or mannose but not galactose. Except for alpha-mannosidase, these reductions in amounts of hydrolase secreted were not accompanied by appreciable changes in intracellular activity, and therefore demonstrate a persistent effect of growth in the presence of certain metabolites on the subsequent secretion of lysosomal hydrolases. Since the inhibition of subsequent secretion depended on both the individual metabolite and the particular hydrolase examined, it appears that the effect of metabolites is not limited to a general inhibition of secretion but may differentially alter some properties of lysosomal subpopulations. A preliminary characterization of the secreted acid protease of Tetrahymena suggests that there may be two acid proteases released, since up to 25% of the activity was not inhibited by high concentrations of pepstatin, leupeptin, or chymostatin.
...
PMID:Effects of metabolites present during growth of Tetrahymena pyriformis on the subsequent secretion of lysosomal hydrolases. 80 52


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

---