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PubMed1978

Amino acid sequence of beta-galactosidase. VI. Limited tryptic digestion of the citraconylated protein and sequences of tryptic peptides.

Hydrolysis with trypsin of citraconyl-carboxy-methyl-beta-galactosidase was carried out under limiting conditions. No Asp-Arg-X sequences were cleaved and many large peptides were produced. Butanol extraction from dilute acid proved very useful for separating the more hydrophobic fragments. Peptides were purified and sequenced. From this digest and two earlier preparations, all 80 theoretically possible tryptic fragments have been isolated and their structures determined.

Amino Acid Sequence↗

PubMed1990

Selection of recombinant vaccinia viruses (Tian Tan strain) expressing hepatitis B virus surface antigen by using beta-galactosidase as a marker.

We constructed a plasmid that contains a small piece of DNA with two vaccinia promoters running in opposite directions--a promoter from a late gene encoding an 11 K polypeptide (P11) and a promoter from an early gene encoding 25K (P25). These promoters were isolated from the Tian Tan strain of vaccinia virus and were flanked by the thymidine kinase (TK) sequence of the same virus. Genes encoding the hepatitis B virus surface antigen (HBsAg) and the Escherichia coli beta-galactosidase (LacZ) were inserted downstream of the 11 K and 25 K promoters respectively so that coexpression plasmids were constructed. Recombinant vaccinia viruses were selected directly by picking blue plaques formed under overlaying agarose medium containing X-gal. HBsAg was expressed to high level by these recombinant viruses. These recombinant viruses showed reduced virulence on rabbit skin and induced anti-HBs after intradermal inoculation of rabbits.

Animals↗

PubMedDate not supplied

[The purification of beta-galactosidase by flow electrophoresis].

A plant has been constructed for the free-flow electrophoresis. It permits carrying out electrophoretic separation both in a free flow and with the use of neutral grained fillers. Beta-galactosidase has been purified from the culture liquid of the Escherichia coli cell phage lysate. Its content in the purified material amounted to 81.2

Densitometry↗

PubMed1990

[Early detection of scleroderma in quartz dust exposed workers and workers with silicosis by determining serum beta-galactosidase activity].

Progressive systemic sclerosis (PSS) is a rare disease belonging to the collagen diseases. PSS is frequently observed in workers with an intensive exposure to crystalline silica and with silicosis in the GDR. The recognition as an occupational disease is regulated by law. The elevated beta-galactosidase activity in the serum of patients with silicosis and beginning PSS can be used for detecting of early stages of PSS. References are given to medical care of patients with silicosis and exposure to quartz.

Adolescent↗

PubMed1990

[Partial deletion of alpha-galactosidase A gene in a Japanese mutant of Fabry disease].

We identified a structural defect of alpha-galactosidase A (alpha-Gal A) gene in a Japanese patient with Fabry disease. A partial deletion approximately 0.4 kilobase-pairs in size was delineated by restriction endonuclease mapping; whole exon 3 sequence was removed. alpha-Gal A mRNA was deficient in the mRNA preparation from the lymphoblastoid cells derived from the patient, and a faulty transcription resulting in an unstable alpha-Gal A message was suggested in this case. Molecular pedigree analysis was successfully performed in identifying heterozygotes and the ancestry of the mutant allele in this family.

Adult↗

PubMed1988

Expression in bacteria of beta-galactosidase fusion proteins carrying antigenic determinants of the two X gene products of bovine leukemia virus.

A cDNA corresponding to the bovine leukemia virus post-envelope region (X gene) was subcloned into the lambda gt11 expression vector. Two large protein fragments corresponding respectively to the long and short open reading frames of the X region were expressed as beta-galactosidase fusion proteins. These products were specifically recognized by sera from bovine leukemia virus-infected cattle.

Animals↗

PubMedDate not supplied

[Interaction of block-polyurethane containing lactose linkages and immobilized beta-galactosidase with body tissues].

Biodegradation of the polymeric composition containing immobilized beta-galactosidase after implantation and its effect on the surrounding tissues are examined. Immunogenicity of the composition is studied by the method of the immunoenzymic analysis. Activation of the immune system is shown to occur in the process of the composition degradation.

Acid Phosphatase↗

PubMed1989

[Construction of promoter-probe vectors on the basis of a modified beta-galactosidase gene of Escherichia coli].

Plasmid-based promoter-probe vectors pPV4 and pPV5 have been constructed which are useful for comparing the relative efficiencies of bacterial promoters. The vectors utilize the beta-galactosidase (lacZ) gene of E. coli as an indicator gene. The latter was modified using synthetic DNA fragments. The promotor-probe system contains the ampicillin resistance gene and the origin of replication of plasmid pBR322. The plasmids pPV4 and pPV5 carry clustered unique restriction sites usable for promoter insertions, and SD sequence. A synthetic DNA fragment corresponding to transcription terminator was inserted downstream the lacZ gene. Presence of the terminator made it possible to clone strong promoters controlling transcription of the lacZ gene. To prevent any undesired promotor effect, the plasmid pPV5 has also second synthetic terminator upstream from the polylinker sequence. Using this promoter-probe system, relative efficiencies of a series of synthetic promoters, including PL promoter of phage lambda and its mutant, gene X promotor of phage fd and several model statistic promoters, have been compared.

Ampicillin Resistance↗

PubMed1989

[Expression of synthetic human angiogenin gene in E. coli in cleaved beta-galactosidase-angiogenin protein].

A synthetic gene coding for human angiogenin was cloned in pUR290 plasmid in frame with beta-galactosidase, both parts of the resultant fused protein being joined through an Asp-Pro sequence. The fused protein, synthesised in E. coli cells upon IPTG induction and isolated as inclusion bodies, possessed angiogenic activity on the chick chorioallantois membrane and was cleaved upon acid treatment to yield free angiogenin.

Amino Acid Sequence↗

PubMed1989

Study on the partition of beta-galactosidase from Escherichia coli in aqueous two-phase systems and elaboration of a simple procedure for the purification of the enzyme to homogeneity.

The partition of beta-galactosidase from Escherichia coli in aqueous two-phase systems composed of poly(ethylene glycol)/Aquaphase PPT or poly(ethylene glycol)/potassium phosphate, respectively, has been studied thoroughly by varying diverse parameters of the phase forming conditions. The enzyme was found to partition in both systems predominantly to the upper poly(ethylene glycol) containing phase, while the protein bulk of E. coli is concentrated in the lower phase. Optimum conditions for the employment of the two-phase partition for the purification of the enzyme were elaborated leading to a simple and effective procedure in which the enzyme was isolated to homogeneity with 70% recovery.

Chromatography, DEAE-Cellulose↗

PubMed1989

Lectin histochemistry of an ovine lysosomal storage disease with deficiencies of beta-galactosidase and alpha-neuraminidase.

Lectin histochemistry is a useful technique to identify and to localize in cells and tissues the terminal carbohydrate moieties of glycoproteins and glycolipids. The specific diagnosis of some glycoprotein storage diseases was accomplished using lectin staining patterns, and such methods of diagnosis have been attempted for some glycolipid storage diseases. This technique was applied to formalin-fixed paraffin-embedded and frozen neural, hepatic, and renal tissues of sheep with an inherited lysosomal storage disease with deficiencies of beta-galactosidase and alpha-neuraminidase. The cytoplasm of central nervous system neurons of affected sheep in paraffin-embedded sections stained with peanut agglutinin (PNA), Ricinus communis agglutinin-I (RCA-I), Dolichos biflorus agglutinin (DBA), and soybean agglutinin (SBA). The cytoplasm of neurons in frozen sections of these tissues stained with PNA, RCA-I, wheat germ agglutinin (WGA), and Ulex europaeus agglutinin-I (UEA-I). The cytoplasm of frozen and paraffin-embedded sections of liver and kidney of affected sheep stained with PNA, whereas paraffin-embedded sections also stained with RCA-I. These results suggest the stored material in this disease has terminal saccharide moieties consisting of beta-galactose, N-acetylneuraminic acid, and N-acetylgalactosamine. Paraffin processing altered lectin staining patterns. Although the staining pattern in this glycolipid storage disease was complex, lectin histochemistry may prove to be a useful technique for the characterization of storage products and for the diagnosis of lysosomal storage diseases.

Animals↗

PubMed1989

Polyspecific binding of Escherichia coli beta-galactosidase by murine antibodies to DNA.

To characterize further polyspecific interactions of antibodies to DNA, the binding of sera from autoimmune MRL-lpr/lpr mice to Escherichia coli beta-galactosidase (beta-gal) was analyzed. This protein was selected for study because of preliminary observations that sera from autoimmune mice bound unexpectedly to cloned fusion protein constructions containing beta-gal. Using ELISA assays, sera from MRL-lpr/lpr mice demonstrated high levels of antibodies to both DNA and beta-gal, in titers significantly greater than those of BALB/c controls. Affinity chromatography using beta-gal-Sepharose demonstrated that antibodies enriched for anti-beta-gal activity bound both DNA as well as beta-gal, indicating the presence of a population of cross-reactive anti-DNA antibodies. Furthermore, anti-DNA mAb of MRL-lpr/lpr strain origin also bound beta-gal by ELISA, although these levels were lower than those to DNA. Together, these results extend the range of polyspecific binding of murine anti-DNA antibodies to bacterial proteins. They further suggest caution in the interpretation of immunoassays using fusion protein constructions containing beta-gal, especially with sera from autoimmune mice.

Animals↗

PubMed1989

Galantase (beta-galactosidase) treatment in pediatric practice.

The authors diagnosed lactose malabsorption by the breath hydrogen analysis in 11 premature and mature babies, in 16 infants and in 28 children between the ages of 3-18 years. All patients were treated with Galantase (beta-galactosidase). According to the results, Galantase is very effective in splitting of lactose of breast-milk, cow-milk and artificial formulas. Pathological hydrogen increase was not detected during the treatment.

Adolescent↗

PubMed1986

[Variants of phage M13 DNA containing a fragment of the beta-galactosidase gene--a convenient mutation system for the study of oligonucleotide-directed mutagenesis].

A model system is developed to test oligonucleotide-directed mutations: T----C transition, T and C deletions (delta T and delta C), C insertion, double mutations (A----G, delta T), (T----C, A----G), and large oligonucleotide deletions (36 or 44 nucleotides). The system includes 9 variants of the phage M13 DNA carrying fragment of beta-galactosidase gene, and oligodeoxyribonucleotides partially noncomplementary to DNA sequence of this gene. Six variants are obtained by the site-localized mutagenesis, the other were described earlier. Induced mutations are easily tested by phenotype change of transformed bacteria (Lac+----Lac-); by formation or loss of the sites for BamHI and EcoRI restrictases; by DNA hybridization with 32P-labeled oligonucleotides; and by DNA sequencing by the Sanger method. The system is used to study the role of some factors, such as completeness of RF DNA synthesis, thermal stability of the oligonucleotide: DNA complex, quality of enzymes and substrates used in polymerase reaction, mutation type or the efficiency of mutagenesis. A number of unexpected mutations were observed in the course of oligonucleotide-directed mutagenesis. Lower yields of some mutants induced by oligonucleotides are shown to be due to the action of repair systems of bacteria.

Coliphages↗

PubMed1986

Immunoelectron microscopical localization of lysosomal beta-galactosidase and its precursor forms in normal and mutant human fibroblasts.

Immunoelectron microscopy was performed to study the biosynthesis of lysosomal beta-galactosidase (beta-gal) in normal and mutant human fibroblasts. Using polyclonal and monoclonal antibodies we show in normal cells precursor forms of beta-gal in the rough endoplasmic reticulum (RER) and in the Golgi apparatus throughout the stack of cisternae. In the lysosomes virtually all beta-gal exists as a high molecular weight multimer of mature enzyme. In the autosomal recessive disease GM1-gangliosidosis caused by a beta-gal deficiency and in galactosialidosis, associated with a combined deficiency of lysosomal neuraminidase and beta-gal, precursor forms of the latter enzyme are found in RER, Golgi and some labeling is present at the cell surface. The lysosomes remain unlabeled, indicative for the absence of enzyme molecules in this organelle. In galactosialidosis fibroblasts also no mature beta-gal is found in the lysosomes but in these cells the presence of the monomeric form can be increased by leupeptin (inhibition of proteolysis) whereas addition of a partly purified 32 kDa "protective protein" results in the restoration of high molecular weight beta-gal multimers in the lysosomes.

Antibodies↗

PubMed1987

[Possible role of the macromolecular environment in enzyme functioning in the cell. Interaction of E. coli beta-galactosidase with endogenous polycationic proteins and kinetic parameters of the enzyme in situ].

The effect of endogenous protein polycations on the kinetic properties of beta-galactosidase was studied. The dependence of kinetic properties of the enzyme (Km and V) in situ at the growth stage of microbial cultures was demonstrated. The observed phenomenon may be explained by the enzyme interaction with endogenous polycations. This interaction is of limited specificity, since it involves different types of biomolecules which display similar polyelectrolyte properties.

Bacterial Proteins↗

PubMed1987

Effective reduction of lactose maldigestion in preschool children by direct addition of beta-galactosidases to milk at mealtime.

We examined the efficiency of two beta-galactosidase preparations--one derived from the yeast, Kluyveromyces lactis (Lactaid), the other derived from the fungus, Aspergillus oryzae (Takamine)--to assist the in vivo digestion of lactose consumed by healthy Guatemalan preschool children. Milk prehydrolyzed by in vitro incubation with enzymes was used as the standard of reference, and the degree of incomplete digestion of lactose from 240 mL of milk was determined using the hydrogen breath test. In in vivo dose-response studies, both 3,250 neutral lactose units of Lactaid and 6,635 food and chemical codex lactose units of Takamine completely eliminated excess H2 excretion in a small sample of lactose-maldigesting subjects. When evaluated in a controlled, clinical trial setting, the same dose of Lactaid added directly to the milk at consumption produced an 82% relative reduction in H2 excretion, whereas Takamine was equally as effective as the prehydrolyzed milk. Thus, intraluminal conditions and gastrointestinal transit in the preschool child support the effective assisted digestion of milk lactose in an efficient manner and with the same enzyme to milk ratios as observed previously in adults.

Animals↗

PubMed1987

[Determination of beta-galactosidase activity on nitrocellulose plates using 5-bromo-3-indolyl-beta-D-galactopyranoside and tetrazolium salts].

A simple and convenient technique has been developed for detection of beta-galactosidase from E. coli on nitrocellulose sheets using a mixture of 5-bromoindol-3-yl-beta-D-galactopyranoside and nitro blue tetrazolium, which enables rapid detection of fmole (10(-15) mole) quantities of the enzyme at pH 9.5. The technique has the following advantages: the substrates are stable for a long period; reaction products give non-fading intense blue colour, resolution is extremely good with essentially no diffusion.

Chemical Phenomena↗