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PubMed1991

A 3' splice site consensus sequence mutation in the intron 3 of the alpha-galactosidase A gene in a patient with Fabry disease.

Fabry disease is an X-linked disorder accompanied with accumulation of glycosphingolipids resulting from the deficient activity of the lysosomal hydrolase, alpha-galactosidase A (alpha-GalA). In the present study, mRNA for alpha-GalA in fibroblasts from an 11-year-old Japanese patient with Fabry disease was examined using the reverse transcriptase-polymerase chain reaction (PCR). The shorter message of alpha-GalA was demonstrated in this patient when compared with the normal control. The complete deletion of exon 4 in the mRNA for alpha-GalA in the patient was disclosed by analysis of cDNA with restriction enzyme digestion and asymmetrical PCR sequencing. The direct sequencing of the genomic DNA demonstrated a single base substitution (G----A) at the 3' end of the consensus sequence of intron 3. This mutation destroyed a splice site in the alpha-GalA, which produced a mutant allele. It was also shown that the mother of the patient had this mutant as well as normal alleles as a heterozygote.

Child↗
PubMed2000

Isolation and characterization of beta-galactosidase from Lactobacillus crispatus.

beta-Galactosidase was isolated from the cell-free extracts of Lactobacillus crispatus strain ATCC 33820 and the effects of temperature, pH, sugars and monovalent and divalent cations on the activity of the enzyme were examined. L. crispatus produced the maximum amount of enzyme when grown in MRS medium containing galactose (as carbon source) at 37 degrees C and pH 6.5 for 2 d, addition of glucose repressing enzyme production. Addition of lactose to the growth medium containing galactose inhibited the enzyme synthesis. The enzyme was active between 20 and 60 degrees C and in the pH range of 4-9. However, the optimum enzyme activity was at 45 degrees C and pH 6.5. The enzyme was stable up to 45 degrees C when incubated at various temperatures for 15 min at pH 6.5. When the enzyme was exposed to various pH values at 45 degrees C for 1 h, it retained the original activity over the pH range of 6.0-7.0. Presence of divalent cations, such as Fe2+ and Mn2+, in the reaction mixture increased enzyme activity, whereas Zn2+ was inhibitory. The Km was 1.16 mmol/L for 2-nitrophenyl-beta-D-galactopyranose and 14.2 mmol/L for lactose.

Animals↗
PubMed2003

Production, partial purification and some properties of beta-galactosidase from Aspergillus carbonarius.

Production of beta-galactosidase by Aspergillus carbonarius grown on deproteinized cheese whey as basal medium was optimized (cultivation period of 6 d, pH 4.5, cultivation temperature 30 degrees C). The enzyme was partially purified (52.9-fold with an overall yield of 45.3% and a final specific activity of 4588 mu kat/g protein. The optimum pH for the enzyme activity was pH 4.5. The enzyme is to some extent thermostable. Metal ions are not required for enzyme activity. The enzyme may be considered for prospective use in food industry.

Aspergillus↗
PubMed2005

Relationship between X-inactivation and clinical involvement in Fabry heterozygotes. Eleven novel mutations in the alpha-galactosidase A gene in the Czech and Slovak population.

We have identified 21 different alpha-galactosidase A gene (GLA) mutations in 22 unrelated Czech and Slovak families with Fabry disease. Eleven of these mutations were novel (point mutations D93N, A135V, D155H, G171R, Q280K, G360S, Q330X, splicing errors c.194ins14, c.801ins36 and deletions c.674_732del59, g.3405_6021del2617). Genotyping of family members for family-specific mutations revealed 55 heterozygotes that manifested clinical symptoms of different severity. To examine the contribution of X-inactivation skewing to disease manifestation in Fabry heterozygotes, we have adopted the Mainz severity scoring scheme and compared the score values with the X-inactivation status in 39 carriers in an age-dependent manner. The age-score trendline of Fabry females who had a predominantly inactivated X-chromosome bearing a wild-type GLA allele (10 of 38 females) was markedly steeper than in the rest of the cohort. One female carrier with an inactivated mutated allele had a low score value when compared to the other heterozygotes of the same age. These data suggest that X-inactivation is indeed a major factor determining the severity of clinical involvement in Fabry heterozygotes. There was a statistically significant difference between the severity score values of heterozygotes with random and non-random X-chromosome inactivation at the 5% level of significance. Further studies will show if the degree of the wildtype allele inactivation will be useful as a predictive marker of severity of phenotype in Fabry heterozygotes. Although the correlation between X-inactivation skewing and presentation of the disease in Fabry heterozygotes has previously been suggested in the literature, this report is among the first attempts to examine this relationship systematically.

Adolescent↗
PubMed2003

A rapid enzyme assay for beta-galactosidase using optically gated sample introduction on a microfabricated chip.

The ability to perform enzyme assays on microchips is demonstrated using optically gated sample introduction. The hydrolysis of fluorescein mono- beta- d-galactopyranoside (FMG) by beta- d-galactosidase ( beta-Gal) is continuously monitored using a microchip for 5 to 10 min. The outcome of the reaction was analyzed by performing serial on-chip separations of fluorescent substrate, FMG, and product, fluorescein. Kinetic information about beta-Gal has been successfully obtained by varying the concentration of FMG. beta-Gal enzymes from two different sources including bovine liver and E. coli., have been examined and compared to each other and to results obtained using traditional assay methods. In addition, the competitive inhibition of beta-Gal by phenylethyl beta- d-thiogalactoside (PETG) and beta-lactose has been studied using this technique. PETG is found to have higher inhibition than lactose in the hydrolysis. This separation-based enzyme assay technique avoids the possible fluorescence interference between FMG and fluorescein, which is a problem with the traditional plate assay method. Additionally, the amount of the enzyme and substrate required with this technique is at least four orders of magnitude lower than the traditional plate assay method. By using optically gated sample introduction, microchips allow continuous serial injections and separations without any potential switch, thus making this technique ideal as a sensor for enzyme assays. This technique should therefore be valuable for high-throughput screening in the drug discovery industry.

Fluoresceins↗
PubMed2006

Measurement of hydrolysis kinetics of galactose-substituted fluorescein by beta-galactosidase at the toluene-water interface by spinning microtube fluorometry.

A new analytical technique, spinning microtube fluorometry (SMF), was developed and applied to the study of interfacial hydrolysis of 5-dodecanoylaminofluorescein di-beta-D: -galactopyranoside (C12FDG) by beta-galactosidase (beta-gal) in the toluene-water system. The nonfluorescent lactone form of C12FDG in the toluene phase was converted at the interface to 5-dodecanoylaminofluorescein (C12F), which was fluorescent in the aqueous phase as a dianion at pH 7.3, though some part of C12F was extracted into the toluene phase as its nonfluorescent lactone form. The distribution ratios of C12FDG and C12F at pH 7.3 were determined as 1.4 x 10(2) and 1.97, respectively. The interfacial adsorption constants from the toluene phase to the interface at pH 7.3 were 4.8 x 10(-4) and 1.7 x 10(-2) dm for C12FDG and C12F, respectively. The kinetic experiments with the SMF method concluded that the rate-determining step of the enzymatic hydrolysis at the interface and in the aqueous phase was the 1:1 reaction of C12FDG and beta-gal and that the hydrolysis reaction rate constant at the interface at pH 7.3 was 1.84 x 10(3) M(-1)s(-1), almost equal to that in the aqueous solution, 1.76 x 10(3) M(-1)s(-1). Finally, the SMF method revealed that the contribution of the interfacial reaction to the overall hydrolysis reaction rate of the toluene-water system was as high as 97%.

Enzyme Stability↗
PubMed2002

Purification and characterization of a recombinant beta-galactosidase with transgalactosylation activity from Bifidobacterium infantis HL96.

A beta-galactosidase isoenzyme, beta-Gall, from Bifidobacterium infantis HL96, was expressed in Escherichia coli and purified to homogeneity. The molecular mass of the beta-Gall subunit was estimated to be 115 kDa by SDS-PAGE. The enzyme appeared to be a tetramer, with a molecular weight of about 470 kDa by native PAGE. The optimum temperature and pH for o-nitrophenyl-beta-D-galactopyranoside (ONPG) and lactose were 60 degrees C, pH 7.5, and 50 degrees C, pH 7.5, respectively. The enzyme was stable over a pH range of 5.0-8.5, and remained active for more than 80 min at pH 7.0, 50 degrees C. The enzyme activity was significantly increased by reducing agents. Maximum activity required the presence of both Na+ and K+, at a concentration of 10 mM. The enzyme was strongly inhibited by p-chloromercuribenzoic acid, divalent metal cations, and Cr3+, and to a lesser extent by EDTA and urea. The hydrolytic activity using lactose as a substrate was significantly inhibited by galactose. The Km, and Vmax values for ONPG and lactose were 2.6 mM, 262 U/mg, and 73.8 mM, 1.28 U/mg, respectively. beta-Gall possesses strong transgalactosylation activity. The production rate of galactooligosaccharides from 20% lactose at 30 and 60 degrees C was 120 mg/ml, and this rate increased to 190 mg/ml when 30% lactose was used.

Bifidobacterium↗
PubMed2003

Synthesis of alpha-galactooligosaccharides with alpha-galactosidase from Lactobacillus reuteri of canine origin.

Crude cell-free extracts from Lactobacillus reuteri grown on cellobiose, maltose, lactose and raffinose were assayed for glycosidic activities. When raffinose was used as the carbon source, alpha-galactosidase was produced, showing the highest yield at the beginning of the stationary growth phase. A 64 kDa enzyme was purified by ultra- and gel filtration, and characterized for its hydrolytic and synthetic activity. Highest hydrolytic activity was found at pH 5.0 at 50 degrees C ( K(M) 0.55 mM, V(max) 0.80 micromol min(-1) mg(-1) of protein). The crude cell-free extract was further used in glycosyl transfer reactions to synthesize oligosaccharides from melibiose and raffinose. At a substrate concentration of 23% (w/v) oligosaccharide mixtures were formed with main products being a trisaccharide at 26% (w/w) yield from melibiose after 8 h and a tetrasaccharide at 18% (w/w) yield from raffinose after 7 h. Methylation analysis revealed the trisaccharide to be 6' alpha-galactosyl melibiose and the tetrasaccharide to be stachyose. In both cases synthesis ceased when hydrolysis of the substrate reached 50%.

Animals↗
PubMed2004

Effect of pH on Lactobacillus fermentum growth, raffinose removal, alpha-galactosidase activity and fermentation products.

In this study, the behaviour of Lactobacillus fermentum CRL 722 and CRL 251 were evaluated under different pH conditions (pH 6.0, 5.5, 5.0, 4.5) and without pH control. Growth was similar under all conditions assayed except at pH 4.5. These microorganisms were able to eliminate raffinose, a nondigestible alpha-oligosaccharide (NDO) found in soy products, showing a consumption rate of 0.25 g l(-1) h(-1) (pH 6.0-5.0). The removal of raffinose was due to the high alpha-galactosidase (alpha-gal) activities of these lactic acid bacteria, which was highest at pH 5.5 (5.0 U/ml). The yield of organic acids produced during raffinose consumption was also highest at this pH. The results of this study will allow selection of the optimum growth conditions of L. fermentum with elevated levels of alpha-gal to be used in the reduction of NDO in soy products when used as starter cultures.

Fermentation↗
PubMed2004

beta-galactosidase from Bifidobacterium adolescentis DSM20083 prefers beta(1,4)-galactosides over lactose.

Abstract A beta-galactosidase gene (beta-Gal II) from Bifidobacterium adolescentis DSM 20083 was cloned into a pbluescript SK (-) vector and expressed in Escherichia coli. The recombinant enzyme was purified from the cell extract by anion-exchange and size-exclusion chromatography. beta-Gal II had a native molecular mass of 235 kDa and the subunits had a molecular mass of 81 kDa, indicating that beta-Gal II occurs as a trimer. The enzyme was classified as belonging to glycosyl hydrolase family 42. The optimal pH was 6.0 and the optimal temperature was 50 degrees C, usingp-nitrophenyl-(beta-D-galactopyranoside as a substrate. The Km and Vmax for Gal(beta1-4)Gal were 60 mM and 1129 U/mg, respectively. The recombinant beta-Gal II was highly active towards Gal(beta1-4)Gal and Gal (beta1-4)Gal-containing oligosaccharides; only low activity was observed towards Gal(beta1-3)Gal, lactose, and Gal (beta1-3)GalOMe. No activity was found towards Gal(beta1-6)Gal, Gal(beta -4)Man, Gal(alpha1-4)Gal, Gal(alpha1-3)Gal(beta1-4)Gal, cellobiose, maltose and sucrose. beta-Gal II was inhibited at high substrate concentrations (100 mg/ml) and no transglycosylation activity was found. At lower substrate concentrations (10 mg/ml) only low transglycosylation activity was found; the Gal/[Gal(beta1-4)]2Gal peak area ratio was 9:1.

Amino Acid Sequence↗
PubMed1999

Transglycosidase activity of Bifidobacterium adolescentis DSM 20083 alpha-galactosidase.

Bifidobacterium adolescentis, a gram-positive saccharolytic bacterium found in the human colon, can, alongside other bacteria, utilise stachyose in vitro thanks to the production of an alpha-galactosidase. The enzyme was purified from the cell-free extract of Bi. adolescentis DSM 20083T. It was found to act with retention of configuration (alpha-->alpha), releasing alpha-galactose from p-nitrophenyl galactoside. This hydrolysis probably operates with a double-displacement mechanism, and is consistent with the observed glycosyltransferase activity. As alpha-galactosides are interesting substrates for bifidobacteria, we focused on the production of new types of alpha-galactosides using the transgalactosylation activity of Bi. adolescentis alpha-galactosides. Starting from melibiose, raffinose and stachyose oligosaccharides could be formed. The transferase activity was highest at pH 7 and 40 degrees C. Starting from 300 mM melibiose a maximum yield of 33% oligosaccharides was obtained. The oligosaccharides formed from melibiose were purified by size-exclusion chromatography and their structure was elucidated by NMR spectroscopy in combination with enzymatic degradation and sugar linkage analysis. The trisaccharide alpha-D-Galp-(1-->6)-alpha-D-Galp-(1-->6)-D-Glcp and tetrasaccharide alpha-D-Galp-(1-->6)-alpha-D-Galp- (1-->6)-alpha-D-Galp-(1-->6)-D-Glcp were identified, and this indicates that the transgalactosylation to melibiose occurred selectively at the C-6 hydroxyl group of the galactosyl residue. The trisaccaride alpha-D-Galp-(1-->6)-alpha- D-Galp-(1-->6)-D-Glcp formed could be utilised by various intestinal bacteria, including various bifidobacteria, and might be an interesting pre- and synbiotic substrate.

Animals↗
PubMed2002

Suicide gene therapy using E. coli beta-galactosidase.

PURPOSE: Suicide gene therapy offers the potential to increase the selective toxicity of antitumor agents by intratumoral expression of exogenous enzymes that convert nontoxic prodrugs to toxic products. The use of herpes simplex virus thymidine kinase with ganciclovir, and E. coli cytosine deaminase with 5-fluorocytosine are well-known examples of this approach. The purpose of this study was to investigate a novel suicide gene therapy using E. coli beta-galactosidase (beta-gal) as the prodrug-activating enzyme. Advantages of this approach include: (1) the ability to use prodrugs that are cleaved by beta-gal to agents that are known to possess activity against human solid tumors, and (2) the extensive experience gained with targeting beta-gal to specific tumors in experimental animals and in humans. METHODS: Two different structural types of anthracycline prodrugs, N-[4"-(beta- D-galactopyranosyl)-3"-nitrobenzyloxycarbonyl]daunomycin (Daun02) and N-[(4" R,S)-4"-ethoxy-4"-(1"'- O-beta- D-galactopyranosyl)butyl]daunorubicin (gal-DNC4) were investigated. The prodrugs were evaluated as substrates for beta-gal. Cytotoxicity studies of Daun02 were conducted against a murine tumor (Panc02), two human breast tumors (MCF-7 and T47D), and three human prostate tumors (PC3, DU145 and LNCAP) that had been transduced to express beta-gal. Antitumor studies of Daun02 were conducted against mouse tumor Panc02 xenografts implanted subcutaneously. RESULTS: Daun02 was a good substrate for beta-gal. By comparison, gal-DCN4 was a poor substrate. Except for PC3, the beta-gal-transduced tumors showed 3- to 60-fold increased sensitivity to Daun02 compared with mock-transduced control cells. Daunomycin was formed from Daun02 in tissue culture medium containing beta-gal-transduced cell lines but was not observed in the medium from mock-transduced controls. In vivo therapeutic studies of Daun02 against the Panc02 tumor in athymic mice showed no significant inhibition of tumor growth. Pharmacokinetic studies showed limited distribution of the prodrug beyond the vascular space. CONCLUSIONS: E. coli beta-gal may be useful as a prodrug-activating enzyme in suicide gene therapy and has the potential to increase the selective toxicity of conventional antitumor agents. Although this approach worked well against tumor cells in vitro, it was not effective against a xenograft model in vivo, apparently because of poor drug-tissue distribution.

Animals↗
PubMed2006

A thermostable alpha-galactosidase from Lactobacillus fermentum CRL722: genetic characterization and main properties.

Alpha-galactosidase (alpha-Gal) enzyme, which is encoded by the melA gene hydrolyzes alpha-1,6 galactoside linkages found in sugars, such as raffinose and stachyose. These alpha-galacto-oligosaccharides (alpha-GOS), which are found in large quantities in vegetables, such as soy, can cause gastrointestinal disorders in sensitive individuals because monogastric animals (including humans) do not posses alpha-Gal in the gut. The use of microbial alpha-Gal is a promising alternative to eliminate alpha-GOS in soy-derived products. Using degenerate primers, the melA gene from Lactobacillus (L.) fermentum CRL722 was identified. The complete genomic sequence of melA (2223 bp), and of the genes flanking melA, were obtained using a combination of polymerase chain reaction-based techniques, and showed strong similarities with the alpha-Gal gene of thermophilic microorganisms. The alpha-Gal gene from L. fermentum CRL722 was cloned and the protein purified from cell-free extracts of the native and recombinant strains using various techniques (ion exchange chromatography, salt precipitation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and ultra-filtration); Its main biochemical properties were determined. The enzyme was active at moderately high temperatures (55 degrees C) and stable at wide ranges of temperatures and pH. The thermostable alpha-Gal from L. fermentum CRL722 could thus be used for technological applications, such as the removal of alpha-GOS found in soy products. The complete melA gene could also be inserted in other micro-organisms, that can survive in the harsh conditions of the gut to degrade alpha-GOS in situ. Both strategies would improve the overall acceptability of soy-derived products by improving their nutritional value.

Enzyme Stability↗
PubMed2005

Identification of a lactose-responsive element upstream of the promoter of Bacillus megaterium beta-galactosidase-encoding gene mbgA.

The Bacillus megaterium mbgA gene encodes a lactose-hydrolyzing beta-galactosidase. An AraC/XylS-type activator BgaR can activate mbgA transcription in response to lactose. In this report, we show by various deletion analyses and point mutagenesis analyses that an inverted repeat centered at position -60.5 relative to the mbgA transcriptional initiation site is the cis-acting element responsible for lactose induction of mbgA expression.

Bacillus megaterium↗
PubMed2005

A new pharmacological screening assay with Trypanosoma cruzi epimastigotes expressing beta-galactosidase.

We have developed a new pharmacological screening assay for epimastigotes of Trypanosoma cruzi (clone CL-B5) that express the Escherichia coli LacZ gene. The assay is based on determining the activity of the cytoplasmic beta-galactosidase released into the culture on membrane lysis in the presence of the substrate chlorophenol red beta-D-galactopyranoside (CPRG). The experimental conditions were adjusted to find those in which the relationship between epimastigote number and CPRG absorbance was linear over the widest possible range. Absorbance was significantly correlated with the number epimastigote from 5x10(3) to 1.2x10(6) parasites/ml (r=0.98, P<0.01). The optimal final concentration of CPRG was 200 microM and the optimal incubation period was 6 h when parasites were incubated for 3 days. Once the assay was standardized, the trypanocidal activities of nifurtimox and benznidazole were determined both by CPRG assay and microscopic counting, demonstrating the methods utility for drug-screening. The efficacy obtained was comparable to that obtained with the manual method.

Animals↗
PubMed1996

Superfamily of alpha-galactosidase MEL genes of the Saccharomyces sensu stricto species complex.

In order to study the molecular evolution of the yeasts grouped in the Saccharomyces sensu stricto species complex by analysis of the MEL gene family, we have cloned and sequenced two new species-specific MEL genes from Saccharomyces yeasts: S. paradoxus (MELp) and a Japanese Saccharomyces sp. (MELj). The clones were identified by sequence homology to the S. cerevisiae MEL1 gene. Both clones revealed an ORF of 1413 bp coding for a protein of 471 amino acids. The deduced molecular weights of the alpha-galactosidase enzymes were 52,767 for MELp and 52,378 for MELj. The nucleotide sequences of the MELp (EMBL accession no. X95505) and the MELj (EMBL accession no. X95506) genes showed 74.7% identity. The degree of identity of MELp to the MEL1 gene was 76.8% and to the S. pastorianus MELx gene, 75.7%. The MELj coding sequence was 75.1% identical to the MEL1 gene and 80.7% to the MELx gene. The data suggest that MEL1, MELj, MELp, and MELx genes are species-specific MEL genes. The strains studied each have only one MEL locus. The MELp gene is located on the S. paradoxus equivalent of S. cerevisiae chromosome X; the MELj gene was on the chromosome that comigrates with the S. cerevisiae chromosome VII/XV doublet and hybridizes to the S. cerevisiae chromosome XV marker HIS3.

Amino Acid Sequence↗
PubMed2005

Fabry disease: correlation between structural changes in alpha-galactosidase, and clinical and biochemical phenotypes.

Fabry disease comprises classic and variant phenotypes. The former needs early enzyme replacement therapy, and galactose infusion is effective for some variant cases. Attempts of early diagnosis before manifestations appear will begin in the near future. However, it is difficult to predict the phenotype, to determine the therapeutic approach, only from genetic information. Thus we attempted structural analysis from a novel viewpoint. We built structural models of mutant alpha-galactosidases resulting from 161 missense mutations (147 classic and 14 variant), and evaluated the influence of each replacement on the structure by calculating the numbers of atoms affected. Among them, 11 mutants, biochemically characterized, were further investigated by color imaging of the influenced atoms. In the variant group, the number of atoms influenced by amino-acid replacement was small, especially in the main chain. In 85% of the cases, less than three atoms in the main chain are influenced. In this group, small structural changes, located apart from the active site, result in destabilization of the mutant enzymes, but galactose can stabilize them. Structural changes caused by classic Fabry mutations are generally large or are located in functionally important regions. In 82% of the cases, three atoms or more in the main chain are affected. The classic group comprises dysfunctional and unstable types, and galactose is not expected to stabilize the mutant enzymes. This study demonstrated the correlation of structural changes, and clinical and biochemical phenotypes. Structural investigation is useful for elucidating the bases of Fabry disease and clinical treatment.

Amino Acid Substitution↗
PubMed2004

Development of the caput epididymidis studied by expressed proteins (a glutamate transporter, a lipocalin and beta-galactosidase) in the c-ros knockout and wild-type mice with prepubertally ligated efferent ducts.

Expression of a glutamate transporter (EAAC1), a lipocalin (MEP17) and beta-galactosidase (beta-Gal) in histological sections was used to monitor post-natal development of the murine epididymis. Three epithelia in the adult caput of wild-type mice were distinguished: I, the initial segment; II, the proximal caput; and III, the distal caput. The regions in which epithelia I, II and III were situated were called regions I, II and III, respectively. Regions I, II and III developed from a precursor epithelium present on day 14; from day 16, a presumptive region I epithelium was evident and, by day 21, epithelia characteristic of future regions II and III appeared. The relationship between the c-ros gene and the initial segment was studied by investigating the development of the caput epididymidis in transgenic homozygous c-ros knockout (-/-) mice that lack the initial segment, heterozygous (+/-) males and wild-type males in which the efferent ducts had been ligated prepubertally so that the initial segment failed to develop. In mice with prepubertally ligated efferent ducts, regions II and III developed normally but region I was missing in the adult and expression of c-ros was partially decreased. In (-/-) mice, the precursor epithelium was present, differentiation of epithelium II was delayed until day 32 and epithelium I never developed. Thus, caput region I develops before c-ros expression, high testosterone secretion and differentiation of regions II and III but not if the organ is deprived of the oncogene c-ros or testicular exocrine secretions. The caput of the knockout male lacks solely the initial segment so that the efferent ducts are in continuity with the post-initial segment, proximal caput region. The ligand for c-ros may be present in testicular fluid and both ligand and receptor may be necessary for differentiation of epithelia I and II.

Aging↗

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