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PubMed1964

GALACTOSIDASE ACTION ON HUMAN BLOOD GROUP B ACTIVE ESCHERICHIA COLI AND ON RED CELL SUBSTANCES.

The blood group B specificity of Escherichia coli O(86) antigen, a B specific oligosaccharide fraction from it, and the B activity of a preparation of an "infectious mononucleosis receptor" from cattle erythrocytes are destroyed by alpha-galactosidase from the coffee bean, as demonstrated for the E. coli antigen by three methods. Blood group H(O) activity appears simultaneously. Galactose is the only hexose released from all three substances.

ABO Blood-Group System↗
PubMed1964

BETA-GALACTOSIDASE AND LACTOSE FERMENTATION IN THE IDENTIFICATION OF ENTEROBACTERIA INCLUDING SALMONELLAE.

One hundred and fourteen strains of non-lactose fermenters and 127 lactose fermenters on MacConkey's agar have been compared in the 5% and 1% lactose tests and in beta-galactosidase production, using ortho-nitro-phenyl-beta-D-galactopyranoside (O.N.P.G.) as a test substance. The superiority of the O.N.P.G. test in the number of positive results and its rapidity is shown. In general, late or non-lactose fermenting strains of genera, usually lactose-positive, yield a rapidly positive O.N.P.G. reaction. Forty-one wild strains of Salmonella, Proteus, Providencia, and Pseudomonas aeruginosa were found negative in all three tests. Of 1,075 stock strains of Salmonella examined in the O.N.P.G. test, all were negative except nine; four of these were lactose-positive strains. For practical purposes, Salmonella strains in Great Britain may be regarded as O.N.P.G. negative. Among 100 stock strains of Arizona there was considerable variation of behaviour in the O.N.P.G. test and in the 5% and 1% lactose tests. Most strains of Arizona can be considered to yield a positive O.N.P.G. test but a minority give a negative result. The test is recommended for routine use in the differentiation of Salmonella from other enterobacteria and for use in bacterial identification. The 5% lactose fermentation test in parallel is suggested when the O.N.P.G. test is used for isolating routine pathogens, because organisms such as Shigella sonnei, Shigella dysenteriae 1, and Pasteurella pseudotuberculosis are O.N.P.G. positive.

Bacteriological Techniques↗
PubMed1982

Neuraminidase deficiency and accumulation of sialic acid in lymphocytes in adult type sialidosis with partial beta-galactosidase deficiency.

Neuraminidase deficiency has been demonstrated in cultured skin fibroblasts of patients who have adult type sialidosis with partial beta-galactosidase deficiency. A substantial amount of residual enzyme activity has been observed in leukocytes, however. To explain this discrepancy, the nature and distribution of the enzyme were studied. Neuraminidase activity was higher in lymphocytes than in granulocytes of normal controls. In patients' lymphocytes, neuraminidase activity was profoundly decreased and total sialic acid contents were increased 2.3-fold. Two neuraminidases, one sonication-labile and the other sonication-stable, were found in lymphocytes; the former was predominant in cultured skin fibroblasts. The defective enzyme in this disorder was found to be the sonication-labile neuraminidase in both cultured skin fibroblasts and lymphocytes.

Cerebellar Ataxia↗
PubMed1975

Kinetic behavior of microencapsulated beta-galactosidase.

Escherichia coli beta-D-galactosidase (E.C. 3.2.1.23) was immobilized in cellulose nitrate membrane microcapsules and the reaction kinetics with o-nitrophenyl-beta-D-galactopyranoside (ONPG), lactose, and whole milk were studied using both continuous stirred tank and packed bed reactor configurations. The results of the experiments gave effectiveness factors of 0.3 for ONPG, 0.6 to 0.7 for lactose in solution, and close to unity for lactose in milk. Using a coupled mass transfer and kinetic model, it was possible to estimate the permeability of the microcapsule membrane from the reactor data. Membrane permeabilities on the order of 5 X 10(-3) and 3 X 10(-4) cm/sec were estimated for ONPG and lactose, respectively. It was determined that the membrane was the limiting mass transfer resistance for the overall reaction. The analysis showed that within the microcapsule, the reaction is reaction rate limited for lactose and slightly diffusion limited for ONPG.

Cellulose↗
PubMed1980

Hydrophobic chromatography of beta-galactosidase.

The hydrophobic interaction of beta-galactosidase with Sepharose 4B substituted with 3,3'-diaminodipropylamine was studied in both batch and column experiments. The equilibrium and the binding rate constants were determined for different phosphate buffer concentrations. The equilibrium constants exhibit a hysteresis effect, i.e., desorption constants are less than adsorption constants, and the higher the ionic strength to start the desorption, the larger the effect. The rate data are not satisfactorily described by a simple reversible first-order model. The column chromatographic data are semiquantitatively described by a local equilibrium theory without axial dispersion or intraparticle diffusion.

Adsorption↗
PubMed1978

Immune response against the beta-galactosidase enzyme of E. coli at precursor cell level. I. Analysis of the secondary repertoire in BALB/c mice.

The BALB/c secondary response against the beta-galactosidase (beta-gal) enzyme of E. Coli was analyzed at the precursor cell level by using the splenic focus technique. Our results indicate that in immunized mice, one out of 18 000 B cells is able to recognize beta-gal. Among the families of anti-beta-gal monoclonal antibodies, a subset of specific antibodies was detected which is capable of protecting the enzyme from heat denaturation. The frequency of clones making protecting antibodies is 1 out of 90 000 and appears to be fairly constant among different individual mice. Further, the degree of heterogeneity of protecting antibodies analyzed in one individual is very high (250-fold difference in affinity) but comparable to other secondary repertoires. Specific frequencies are compared with previous findings relative to secondary responses against artificial haptens. It is suggested that a different type of recognition exists between protein determinants and artificial haptens. In addition, the relatively high proportion of clones making antibodies of the protecting type suggests that only a small proportion of antigenic sites on the beta-gal is actually able to stimulate an immune response.

Animals↗
PubMed1981

Requirement of the immunogen (E. coli beta-galactosidase) for the response towards a determinant responsible for antibody-mediated enzyme activation, while antibodies binding some other site can be elicited by mitogen alone.

Virgin mouse spleen cells cultured in vitro without antigen or mitogen produced a measurable amount of IgM binding E. coli beta-galactosidase (beta-gal). Lipopolysaccharide (LPS) and LPS plus antigen enhance this response, which cannot be considered truly polyclonal since it does not include the production of antibodies directed towards a conformation-dependent determinant, responsible for the activation of a mutant beta-gal, and known otherwise to be highly immunogenic. By priming in vivo with alum-treated beta-gal (unable to elicit activating antibodies), an activating response is obtained in vitro by LPS plus antigen, but not by LPS alone. These results are compatible with a two-signal requirement for the activation of B cells and may be explained as follows: (a) the mitogen, in absence of immunogen, stimulates those clones which have received a specific signal from cross-reacting structures in the environment: (b) instead, no cross-reaction are available for the conformation-controlled structure of the "activating" determinant; thus, intact immunogen is required as well as mitogen. Because of this "uniqueness", the molecule of beta-gal offers a highly specific tool to probe carrier-hapten relationships in native proteins.

Animals↗
PubMed1989

The molecular context of determinants within the priming antigen establishes a hierarchy of T cell induction: T cell specificities induced by peptides of beta-galactosidase vs. the whole antigen.

The antibody response following priming with a macromolecule or a peptide will depend on the regulatory T cells that become activated by the antigenic determinants available. In this report, activation of T helper (Th) and T suppressor (Ts) cells by determinants on beta-galactosidase (GZ) was examined by comparing native GZ [1023 amino acid (a.a.) residues per monomer] with peptides from the immunodominant region encompassing residues 3 to 187. Each immunogen established its characteristic hierarchy of dominance of determinants within it: in particular, GZ and CB-2-3 (a.a. 3-187) each induced immunodominant Th cells which could not be induced by T8 (a.a. 60-140). Hierarchies of suppressor determinant are also created: T8-Ts suppresses all Th specificities and therefore can be deemed immunodominant: T8-2-Ts and T8-3-Ts have a more selective suppressor activity and can be considered subdominant. We conclude that the outcome of immunization shifts with a change in the nature of the immunogen and the context within which the determinant lies will crucially influence its expression. A particular "context" presumably determines the likely order of processing of that molecule which leads to a characteristic relationship among the Ts, Th and B cell determinants involved.

Animals↗
PubMed1990

Partial tolerance in beta-galactosidase-transgenic mice.

A transgenic mouse line was produced which allowed the expression of E. coli beta-galactosidase (beta-Gal) under the regulatory elements of the immunoglobulin heavy chain locus. Expression of the transgene is found in spleen and bone marrow. Upon immunization of the transgenic mice with beta-Gal, a reduced but clearly detectable antibody response was obtained. Affinity purification with sera from immunized transgenic mice suggests that they contain lower affinity antibodies as compared to normal littermates. Transgenic and nontransgenic mice immunized with bovine serum albumin (BSA) alone or as a mixture with beta-Gal gave comparable anti-BSA responses. Immunization with a chemically cross-linked (Gal-BSA)-protein, however, showed a 10- to 30-fold difference in the anti-BSA response. Partial unresponsiveness to beta-Gal in the transgenic mice is best explained by a dominant, peripheral suppression mechanism linked to the antigen-presenting potential of B cells.

Animals↗
PubMed1985

A positive regulatory element is involved in the induction of the beta-galactosidase gene from Kluyveromyces lactis.

The regulation of the LAC4 gene encoding beta-galactosidase in the yeast Kluyveromyces lactis has been studied. The expression of cloned LAC4 gene present on autonomously replicating plasmids was normally regulated by lactose or galactose as inducers. The LAC4 transcription initiation sites were mapped on two plasmids, PTY75-LAC4 and pKL2. The sites were found to be dependent on the level of gene expression and on the plasmid used. Under induced conditions, the normal cluster of initiation sites was used on both plasmids, whereas under non-induced conditions LAC4 on pKL2 showed additional sites. Deletion mapping of the 5' regulatory region of the LAC4 gene revealed a DNA element required for induction, presumably for the binding of a positive regulator.

Chromosome Deletion↗
PubMed1985

Priming immunization against cholera toxin and E. coli heat-labile toxin by a cholera toxin short peptide-beta-galactosidase hybrid synthesized in E. coli.

A synthetic oligodeoxynucleotide encoding for a small peptide was employed for the expression of this peptide in a form suitable for immunization. The encoded peptide, namely, the region 50-64 of the B subunit of cholera toxin (CTP3), had previously been identified as a relevant epitope of cholera toxin. Thus, multiple immunizations with its conjugate to a protein carrier led to an efficient neutralizing response against native cholera toxin. Immunization with the resulting fusion protein of CTP3 and beta-galactosidase, followed by a booster injection of a sub-immunizing amount (1 microgram) of cholera toxin, led to a substantial level of neutralizing antibodies against both cholera toxin and the heat-labile toxin of Escherichia coli.

Animals↗
PubMed1990

Immobilization and characterization of beta-galactosidase in thermally reversible hydrogel beads.

Beta-Galactosidase has been immobilized within thermally reversible hydrogel beads and has been studied in batch and packed bed reactor systems. The enzyme was entrapped in a copolymer hydrogel of N-isopropylacrylamide (NIPAAm) and acrylamide (AAm) as beads were formed in an inverse suspension polymerization. A reversible deswelling and reswelling of the hydrogel matrix was induced by first warming and then cooling through 37-40 degrees C, which is the lower critical solution temperature, LCST, of the backbone copolymer. The optimum temperature for maximum activity of the immobilized enzyme-gel bead system was found to be 30-35 degrees C in a batch mode and 40 degrees C in a packed bed reactor, which were both below the 50 degrees C optimum for the free enzyme. These differences are understandable, since the mass transfer rates of substrate and product within the pores of the gel matrix are controlled mainly by the temperature, so therefore it is the temperature which governs the overall activity of the immobilized enzyme system. It was also found that when the operational temperature in the packed bed reactor was cycled between temperatures below (35 degrees C) and above (45 degrees C) the copolymer gel LCST, the activity of the immobilized enzyme almost fully recovered after each cycle. In fact, the enzyme-gel system exhibited a complete "shut-off" in activity at 50 degrees C which was the temperature where the free enzyme showed its maximum activity. The thermal cycling operation of LCST enzyme-gel beads can be used to enhance overall activity and productivity of a packed bed reactor, when compared to isothermal operation of this reactor. This is due to the thermally induced "pumping" which enhances mass transfer rates of substrate in and product out of the gel beads.

Enzymes, Immobilized↗
PubMed1988

Galactosialidosis: molecular heterogeneity in biosynthesis and processing of protective protein for beta-galactosidase.

Biosynthesis and processing of the protective protein for beta-galactosidase in normal and galactosialidosis fibroblasts were investigated using specific antiserum preparations. A 45-kd precursor was processed to a mature 30-kd protein in normal fibroblasts. The mature protective protein was not detected in any of the twelve galactosialidosis fibroblast strains examined in this study. The precursor was not detected in two cases and in the others was of heterogeneous molecular weight, i.e., normal, abnormally low, or abnormally high. These molecular abnormalities were not correlated with clinical manifestations of the patients.

Adolescent↗
PubMed1988

Interstitial deletion of the short arm of chromosome 3. Fetal pathology and exclusion of the gene for beta-galactosidase-1 (GLB-1) from 3(p11----p14.2).

A de novo interstitial deletion of the short arm of chromosome 3 was prenatally diagnosed in a male fetus, karyotype 46,XY,del(3)(pter----p14.2::p11----qter). The fetus had craniofacial dysmorphisms, a single transverse palmar crease, ulnar deviation in the wrists, cardiovascular anomalies, a slight ureteric dilatation and a mobile caecum. Our observations are compared with five other cases with interstitial deletion of the short arm of chromosome 3 to delineate further the proximal 3p deletion syndrome. The gene for beta-galactosidase-1 (GLB-1) has previously been assigned to chromosome 3(p21----q21). The absence of a gene dosis effect for GLB-1 in this study indicates exclusion of GLB-1 from 3(p11----p14.2).

Abnormalities, Multiple↗
PubMed1981

Purification and characterization of beta-galactosidase from a strain of Bacillus coagulans.

beta-Galactosidase from B. coagulans strain L4 is produced constitutively, has a mol. wt. of 4.3 x 10(5) and an optimal temperature of 55 degrees C. The optimal pH at 30 degrees C is 6.0 whereas at 55 degrees C it is 6.5. The energy of activation of enzyme activity is 41.9 kJ/mol (10 kcal/mol). No cations are required. The Km with ONPG as substrate is 4.2-5.6 mM and with lactose is 50 mM. The Ki for inhibition by galactose is 11.7-13.4 mM and for dextrose is 50 mM. Galactose inhibited competitively while dextrose inhibited noncompetitively. The purified and unprotected enzyme is 70% destroyed in 30 min at 55 degrees C whereas in the presence of 2 mg/ml of BSA 42% of the activity is destroyed in 30 min at 55 degrees C. An overall purification of 75.3-fold was achieved.

Bacillus↗
PubMed1980

Glucose inhibibion of galactose-induced synthesis of beta-galactosidase in Streptomyces violaceus.

Various carbon compounds inhibited galactose induced synthesis of a beta-galactosidase activity in Streptomyces violaceus. Glucose and 2-deoxyglucose, but not methyl-alpha-D-glucose, caused inhibition of galactose uptake activity. In addition, glucose, or one of its metabolites, inhibited the synthesis of the glactose uptake system. Therefore it is concluded that the main inhibitory activity of glucose on galactose induced enzyme synthesis is exerted through inducer exclusion. Other carbon sources, such as D-ribose, D-gluconate, cellobiose or DL-alpha-glycerophosphate, did not inhibit uptake of the inducer galactose and may exert their effect through catabolite repression, inactivation or direct enzyme inhibition.

Carbohydrates↗
PubMed1978

Effect of guanosine 5'-diphosphate 3'-diphosphate and related nucleoside polyphosphates on induction of tryptophanase and beta-galactosidase in permeabilized cells of Escherichia coli.

Exogenous addition of guanosine and adenosine 5'-(mono, di and tri) phosphate 3'-diphosphates (pppGpp, ppGpp, pGpp, pppApp, ppApp and pApp) stimulated the synthesis of tryptophanase and beta-galactosidase in permeabilized cells of Escherichia coli. From the results obtained with ppGpp and pppApp, this effect appeared to be at a transcriptional level and depended greatly on the growth condition; the largest effect was observed in cells under shiftdown or grown on poor enrgy source. ppGpp and pppApp, unlike cyclic AMP, did not act to overcome the inhibition of enzyme induction by glucose, but in combination with cyclic AMP caused a synergistic stimulation effect. In the shiftdown cells, ppGpp and pppApp gave 30% or more stimulation effect on tryptophanase induction while cyclic AMP did not stimulate induction. There was therefore a pronounced difference between cyclic AMP and ppGpp or pppApp in stimulatory function.

Adenine Nucleotides↗