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)

Acid hydrolases were isolated from the lysosome fraction of beta-galactosidase-deficient human fibroblasts and from the mannose 6-phosphate containing medium in which they were grown. Nearly half of the total beta-hexosaminidase and beta-glucuronidase from both sources bound to Ricin specifically. Lysosomal beta-hexosaminidase, metabolically labelled with [35S]-methionine, was also fractionated on Ricin-agarose. SDS-PAGE of immunoprecipitates from Ricin-binding and non-binding fractions revealed approximately equivalent amounts of cross-reacting material at the appropriate MW. We interpret these results to mean that acid hydrolases which are segregated to lysosomes are exposed to trans-Golgi processing enzymes to about the same extent as enzymes which are secreted, and that segregation by the Man 6-P receptor occurs after transit through the trans-Golgi compartment.
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PMID:Ricin-binding properties of acid hydrolases from isolated lysosomes implies prior processing by terminal transferases of the trans-Golgi apparatus. 293 47

Antisera were raised in rabbits against fusion proteins consisting of beta-galactosidase and partial amino acid sequences of Semliki Forest virus (SFV)-specific non-structural proteins nsP1, nsP2, nsP3 and nsP4. The antisera were specific since each of them precipitated only one labelled protein of a size expected for nsP1, nsP2, nsP3 or nsP4 from lysates of [35S]methionine-labelled SFV-infected BHK-21 cells. The specific antisera also precipitated p220 (with sequences of nsP1, nsP2 and nsP3), p155 (nsP1 and nsP2) and p135 (nsP3 and nsP4) which have been previously shown to be cleavage products of the polyprotein precursor of the non-structural proteins. nsP1, nsP4 and most of nsP3, together with the virus-specific RNA polymerase activity, were in the mitochondrial pellet (P15) fraction of infected BHK-21 cells whereas nsP2 was evenly distributed between P15 and the supernatant fraction (S15). Only antisera directed against nsP3 sequences precipitated a labelled protein from cells incubated with [32P]orthophosphate during SFV infection. Treatment of the immunoprecipitate with calf alkaline intestinal phosphatase reduced the amount of labelled nsP3 considerably. Immunoprecipitated 32P-labelled nsP3, isolated by SDS-PAGE, was subjected to acid hydrolysis. Both phosphoserine and phosphothreonine but not phosphotyrosine could be identified in the hydrolysate. Approximately twice as much [32P]serine as [32P]threonine was detected in nsP3. P15 and S15 fractions were prepared from [35S]methionine- and 32P-labelled SFV-infected cells and the 35S/32P ratio of nsP3 was determined after immunoprecipitation and SDS-PAGE. The nsP3 in S15 was less heavily phosphorylated (about 50%) than P15-associated nsP3. Anti-nsP3 serum revealed large cytoplasmic vesicles in SFV-infected cells in indirect immunofluorescence microscopy.
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PMID:Semliki Forest virus-specific non-structural protein nsP3 is a phosphoprotein. 297 May 23

Lysosomal neuraminidase and beta-galactosidase are present in a complex together with a 32-kDa protective protein. This complex has been purified and the different components have been dissociated using potassium isothiocyanate (KSCN) treatment. beta-Galactosidase remains catalytically active, but neuraminidase loses its activity upon dissociation. The inactive dissociated neuraminidase was purified by removing the remaining non-dissociated beta-galactosidase/protective protein complex using beta-galactosidase-specific affinity chromatography. The dissociated neuraminidase material shows two major polypeptides on SDS-PAGE with an apparent molecular mass of 76 kDa and 66 kDa. Subsequently the 32-kDa protective protein was dissociated from the beta-galactosidase/protective protein complex, and purified. Antibodies raised against the dissociated inactive neuraminidase preparation specifically immunoprecipitate the active neuraminidase present in the complex with beta-galactosidase and protective protein. By immunoblotting evidence is provided that the 76-kDa protein is a subunit of neuraminidase which, in association with the 32-kDa protective protein, is essential for neuraminidase activity.
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PMID:Purification and partial characterization of lysosomal neuraminidase from human placenta. 310 33

Human lactase was isolated from solubilized small-intestinal brush-border membranes by a combination of chromatography on concanavalin A-Sepharose, Bio-Gel 1.5m and chromatofocusing, with a yield of approx. 1% and a 750-fold purification. The enzyme appeared to be homogeneous on SDS/polyacrylamide-gel electrophoresis under both reduced and non-reduced conditions, with an apparent Mr of approx. 170,000. On gel filtration, however, it displayed an apparent Mr of approx. 380,000. The protein had a pI of 4.8, as judged by the chromatofocusing experiment, and had a lactase activity whose optimum is at pH 6.0. In addition to the beta-galactosidase activity, the protein also hydrolysed to various extents cellobiose, phlorizin, p-nitrophenyl beta-D-galactoside, p-nitrophenyl beta-D-glucoside, o-nitrophenyl beta-D-galactoside and o-nitrophenyl beta-D-fucoside. Antisera had been raised against the purified enzyme in two rabbits. One of the antibody populations could inhibit the enzyme in a concentration-dependent manner. This antibody population was used to set up an antibody-bound Sepharose column for the use in an immunoaffinity purification of lactase from crude intestinal homogenate. A partially purified preparation of lactase could thus be obtained. The antibody population was also used to set up a radioimmunoassay for quantifying the enzyme. The competition assay could detect about 0.5 micrograms of lactase protein/ml.
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PMID:Physicochemical characterization of human intestinal lactase. 310 78

A soluble sialidase was copurified apparently as an enzyme complex with acid beta-galactosidase from porcine testis. The sialidase exhibited its maximum activity at acidic pH. It was efficiently active towards 4-methylumbelliferyl-alpha-D-N-acetyl-neuraminic acid and sialyllactose, relatively inactive towards glycoproteins, and had little activity towards glycolipids. The complex could be separated by sucrose gradient centrifugation or isoelectric focusing. The separated enzymes had molecular weights about 600,000 for beta-galactosidase and more than about 1,000,000 for sialidase by Sepharose 4B gel filtration. SDS-polyacrylamide gel electrophoresis of the beta-galactosidase showed three protein bands with molecular weights of 63,000, 31,000 and 20,000.
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PMID:Copurification and separation of beta-galactosidase and sialidase from porcine testis. 310 75

Methods for isolation and purification of beta-galactosidase from Bacillus subtilis, st. IBP-101 are described. The bacterial cells were disrupted by different procedures such as freezing and thawing with subsequent autolysis at 37 degrees C, disrupting in a French press DKM-3 or in ultrasonic disintegrators UZDN-1 (USSR) and Soniprep-150. It is shown that the specific activity and yield of the enzyme depends to a great extent on the disrupting procedure used. The best results were obtained in case of sonication. The preparation was purified by precipitation with ammonium sulphate (25-75% saturated) and chromatography on DEAE-cellulose and DEAE-Sephadex. The purified enzyme had a specific activity of 3155 units per mg protein. The molecular weight of the homogeneous according to gel polyacrylamide electrophoresis preparation was 215,000, as estimated by gel filtration, and 105,000, as estimated by SDS gel electrophoresis. The enzyme retains the activity in the presence of Na+, Mn2+ or Mg2+ ions or the thiolic reagents, dithiothreitol or 2-mercaptoethanol. The pH optimum of the enzyme activity is 6.3 and it is stable in water solutions at pH from 6 to 9 and can be lyophilized. The given preparation of beta-galactosidase has a high affinity for synthetic substrates such as o- and p-nitrophenyl-beta-D-galactopyranosides and 4-methylumbelliferyl-beta-D-galactopyranoside.
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PMID:[Isolation of a highly active preparation of beta-D-galactosidase]. 311 62

1. beta-Galactosidase (EC 3.2.1.23) from chicken seminal plasma was purified approx. 111-fold to homogeneity. 2. pH optimum of the enzyme ranged from 3.6 to 4.0 and its Km was 0.65 mM with p-nitrophenyl-beta-D-galactoside as substrate. 3. The enzyme was unstable at its optimal activity pH and was activated by Cl- ions. 4. The enzyme had pI value of 4.0. 5. The active enzyme had Mr approx. 100,000 by Sephacryl S-300 chromatography. SDS electrophoresis in the presence of beta-mercaptoethanol showed four bands corresponding to Mr of approx. 90,000, 75,000, 65,000 and 13,000.
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PMID:Purification and properties of beta-galactosidase from chicken seminal plasma. 311 19

beta-Galactosidases were purified to homogeneity from livers of a normal control and a patient with the adult form of GM1 gangliosidosis. The purification was achieved by chromatography on DEAE-Sepharose fast flow, Con A-Sepharose, p-aminophenyl-1-thio-beta-D-galactopyranoside-Sepharose, and QAE-Mono Q. The normal and mutant enzymes were purified about 5000-fold with a yield of 10% and 1800-fold with a yield of 34%, respectively, and could hydrolyze 4-methylumbelliferyl-beta-D-galactoside, GM1 ganglioside, and asialofetuin. The purified normal enzyme was eluted from a TSK gel G-4000SW column as three symmetrical peaks of protein which were coincident with the three peaks of enzyme activity. The enzyme in these three peaks had apparent molecular weights of 800,000 (polymer), 140,000 (dimer), and 65,000 (monomer), whereas the mutant enzyme was eluted as two symmetrical peaks of protein and enzyme activity. The apparent molecular weight of a major monomeric form of the enzyme (beta-galactosidase A) was 60,000, and no dimeric form of the enzyme existed. Normal and mutant purified enzyme preparations migrated as a single major protein band with apparent molecular weights of 65,000 or 60,000, respectively, by SDS-polyacrylamide gel electrophoresis after treatment with mercaptoethanol. On isoelectric focussing, the mutant enzyme migrated more anodally than the normal enzyme. The mutant enzyme also had altered enzyme properties, such as pH optimum, Km values, substrate specificity and heat-stability. These data on the characteristics of the purified enzyme preparations provide the first direct evidence that patients with the adult form of GM1 gangliosidosis have a structurally altered beta-galactosidase.
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PMID:Purification and characterization of human liver beta-galactosidase from a patient with the adult form of GM1 gangliosidosis and a normal control. 312 90

The transcriptional and translational signals required for efficient expression of the chloramphenicol acetyltransferase, beta-galactosidase, and tissue plasminogen activator genes, under the control of the polyhedrin promoter in Spodoptera frugiperda cells infected with Autographa californica nuclear polyhedrosis virus, were investigated by SDS-PAGE and RNA dot blot analysis. The recombinant baculoviruses all contained alterations in the leader sequence or 5' proximal coding region of the polyhedrin gene. Highest levels of foreign proteins and polyhedrin-linked mRNAs were observed when portions of the coding sequence of the polyhedrin gene were fused in phase with the foreign gene. Recombinant viruses in which the foreign gene was inserted upstream from the polyhedrin ATG start codon expressed nonfused products but at lower levels than contructs which produced fusion proteins. A corresponding decrease in the levels of mRNAs produced by such constructs was also observed. Some constructs in which the foreign gene was inserted out of phase downstream from the polyhedrin start codon expressed nonfused protein products at low levels but produced polyhedrin-linked mRNA at levels comparable to vectors which produced protein fusions. These data suggest that reinitiation of translation can take place at AUG start codons a short distance downstream from the primary polyhedrin start codon. These results indicate that sequences immediately upstream from the polyhedrin start codon are important for regulation of transcription and that additional sequences near the AUG start codon can have a dramatic influence on the levels of translation observed.
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PMID:Signals important for high-level expression of foreign genes in Autographa californica nuclear polyhedrosis virus expression vectors. 314 47

The complete sequence of P30, the major surface Ag of the protozoan parasite, Toxoplasma gondii, has been deduced through the cloning and analysis of its gene. Using polyclonal serum specific for P30, we have isolated a P30 cDNA clone from a lambda gt11 cDNA expression library derived from tachyzoites of T. gondii (RH strain). This clone produces a beta-galactosidase fusion protein which reacts with several anti-P30 mAb. In addition, polyclonal anti-serum raised to the fusion protein reacts with purified P30 protein and exclusively with P30 in a whole cell lysate of T. gondii. This cDNA clone was used to isolate near full-length cDNA molecules and a cosmid clone containing the P30 gene. Sequence analysis of the cDNA reveals a single open reading frame with coding capacity for 34.7 kDa of primary translation product (consistent with the apparent Mr of P30 on SDS-acrylamide gels) including a presumptive hydrophobic signal sequence. The P30 primary translation product also has a carboxy-terminal hydrophobic tail which is predictive of a posttranslational cleavage and modification with a glycolipid anchor. We have identified the apparent 5' and 3' ends of the P30 mRNA transcript which is extremely abundant, 1500 nucleotides in length, and polyadenylated. The P30 gene is single copy and contains no introns.
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PMID:Molecular analysis of the gene encoding the major surface antigen of Toxoplasma gondii. 318 82


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