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)

Here we report on the construction of two integrative plasmids for Bacillus subtilis allowing in vitro construction of translational fusions. Both plasmids contain two cassettes in tandem: the bgaB gene encoding a heat-stable beta-galactosidase devoid of its own regulatory sequences and the first two codons followed by a neomycin-resistance gene for selection in B. subtilis. Both cassettes are flanked by the 3'- and 5'-end of the amyE gene (encoding alpha-amylase) allowing integration of both cassettes at the amyE locus of the B. subtilis chromosome. For propagation in Escherichia coli, the plasmids contain the pBR322 origin of DNA replication and the beta-lactamase-encoding gene. Whereas one vector needs a promoter, a Shine-Dalgarno sequence and the beginning of a gene fused in-frame to bgaB, the other one already carries a constitutive promoter. The versatility of the gene fusion vectors was demonstrated by the integration of the regulatory regions of the dnaK and the cat-86 genes. In the first case, heat-inducible expression was found, and by comparison with an operon fusion, it seems that the dnaK operon is regulated at both the transcriptional and the posttranscriptional level. In the second case, chloramphenicol-inducible regulation of the gene fusion could be demonstrated.
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PMID:Integrative vector for constructing single-copy translational fusions between regulatory regions of Bacillus subtilis and the bgaB reporter gene encoding a heat-stable beta-galactosidase. 916 5

Parotid and mandibular saliva was obtained from red kangaroos by concurrent acetylcholine isoprenaline stimulation. Salivary proteins were separated by horizontal electrophoresis on either cellulose acetate or starch gels and assessed by specific staining techniques for 23 enzymes commonly found in mammalian tissues and body fluids. Parotid saliva was positive for acid phosphatase, alpha-amylase, carbonic anhydrase, glucose-6-phosphate dehydrogenase, sorbitol dehydrogenase and superoxide dismutase activities. Mandibular saliva was positive for alcohol dehydrogenase in addition to the above six enzymes. The kangaroo salivas lacked activity for alkaline phosphatase, beta-galactosidase and non-specific esterase which occur in saliva from some mammalian species.
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PMID:Enzyme activity in parotid and mandibular saliva from red kangaroos, Macropus rufus. 978 23

When Bacillus subtilis is subjected to phosphate starvation, genes of the Pho regulon are either induced or repressed. Among those induced are genes encoding alkaline phosphatases (APases). A set of isogenic mutants, with a beta-galactosidase gene transcriptionally fused to the inactivated target gene, was used to identify genes that influence the operation of the Pho regulon. One such gene was nhaC (previously yheL). In the absence of NhaC, growth and APase production were enhanced, while the production of other non-Pho-regulon secretory proteins (proteases and alpha-amylase) did not change. The influence of NhaC on growth, APase synthesis, and its own expression was dependent on the external Na+ concentration. Other monovalent cations such as Li+ or K+ had no effect. We propose a role for NhaC in the uptake of Na+. nhaC appears to be encoded by a monocistronic operon and, contrary to previous reports, is not in the same transcriptional unit as yheK, the gene immediately upstream. The increase in APase production was dependent on an active PhoR, the sensor kinase of the two-component system primarily responsible for controlling the Pho regulon. Transcriptional fusions showed that the phoPR operon and both phoA (encoding APaseA) and phoB (encoding APaseB) were hyperinduced in the absence of NhaC and repressed when this protein was overproduced. This suggests that NhaC effects APase production via phoPR.
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PMID:Bacillus subtilis NhaC, an Na+/H+ antiporter, influences expression of the phoPR operon and production of alkaline phosphatases. 1127 10

Changes associated with blood and sugar meal digestion in the sandfly, Phlebotomus langeroni were characterized. Different types of sugars: sucrose, glucose, melibiose, cellobiose, lactose, starch, fig fruits, honey dew and a mixture of sucrose and sugar sources were used for the sandfly feeding. Activities of glycosidases and proteases in the sandfly guts after blood and sugar meals were determined using the endpoint method. The results showed that glycosidases (alpha-glycosidase, beta-glycosidase, alpha-galactosidase, and beta-galactosidase) are present in the sandfly midguts. No activities of the glycosidases (alpha-mannosidase and alpha-amylase) were detected in the sandfly gut. Proteases: trypsin and aminopeptidase showed activities in the sandfly midguts. It is concluded that the midgut glycosidase may play an important role in the vector-parasite interaction. Trypsin and aminopeptidase induction after a blood meal is controlled by a secretogogue mechanism which indirectly influences the outcome of the Leishmania parasite infection.
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PMID:Induction of some digestive enzymes in the midgut of the sandfly Phlebotomus langeroni after sugar and blood meals. 1256 9

The purpose of the present research was to compare the enzyme activity of alkaline phosphatase (ALP), lactate dehydrogenase (LDH), alpha-amylase, alpha-manosidase, beta-N-acetyloglucosaminidase, beta-glucuronidase, and beta-galactosidase in the cervical mucus of cows during spontaneous and induced estrus. Friesian cows (n = 106) were assigned to 4 groups: 1) no treatment; 2) progesterone releasing intervaginal device (PRID) for 12 days plus pregnant mare serum gonadotrophin (PMSG) at the removal of the PRID; 3) PGF2alpha 2 doses 11 days apart; and 4) PRID for 7 days plus PGF2alpha 1 dose, 24 hours before removal of the PRID. Fourteen cows were excluded from the trial because of an inadequate quantity of cervical mucus collected or a lost PRID. The cows from the 3 induced estrus groups were artificially inseminated (AI) twice, while those with spontaneous estrus received only a single AI. Cervical mucus samples were collected from all cows 5 to 30 min before the first AI. The results are summarized as follows: 1) ALP and alpha-amylase activity for spontaneous estrus were similar to those for induced estrus; 2) LDH activity levels during spontaneous estrus were significantly lower (P < 0.001) than that in the P4 and P4+PGF2alpha induced estrus groups; and 3) glycosidases' activity was significantly lower (P < 0.001) in the spontaneous estrus group than that in the induced estrous groups. In conclusion, the activity of most enzymes in the cervical mucus of cows, in the present study, was significantly different between the spontaneous and the induced estrus groups.
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PMID:Enzyme activity in bovine cervical mucus during spontaneous and induced estrus. 1288 24

Expression kinetics of the lactose (lac) operon in Escherichia coli are reviewed for both wild-type and recombinant cell cultures under chemostatic conditions. A unified model which involves regulation of active inducer (lactose) transport, promoter-operator regulated expression of the lac operon, glucose-mediated inducer exclusion, and catabolite repression is summarized and supporting data is shown to verify its accuracy. The synthesis of alpha-amylase with a recombinant form of Bacillus subtilis is also reviewed to point out generic features in transport regulation, the lac operon model providing a point of departure. While there are many similarities in the influence of transport on both regulating models, there are also important differences. In a chemostat system, the synthesis of alpha-amylase is nongrowth associated, while beta-galactosidase is a growth-associated enzyme. Nevertheless, transport regulation is an important feature in both instances.
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PMID:Transport regulation of recombinant gene expression in E. coli and B. subtilis. 1454 79

The diversity of culturable bacteria associated with sea ice from four permanently cold fjords of Spitzbergen, Arctic Ocean, was investigated. A total of 116 psychrophilic and psychrotolerant strains were isolated under aerobic conditions at 4 degrees C. The isolates were grouped using amplified rDNA restriction analysis fingerprinting and identified by partial sequencing of 16S rRNA gene. The bacterial isolates fell in five phylogenetic groups: subclasses alpha and gamma of Proteobacteria, the Bacillus-Clostridium group, the order Actinomycetales, and the Cytophaga-Flexibacter-Bacteroides (CFB) phylum. Over 70% of the isolates were affiliated with the Proteobacteria gamma subclass. Based on phylogenetic analysis (<98% sequence similarity), over 40% of Arctic isolates represent potentially novel species or genera. Most of the isolates were psychrotolerant and grew optimally between 20 and 25 degrees C. Only a few strains were psychrophilic, with an optimal growth at 10-15 degrees C. The majority of the bacterial strains were able to secrete a broad range of cold-active hydrolytic enzymes into the medium at a cultivation temperature of 4 degrees C. The isolates that are able to degrade proteins (skim milk, casein), lipids (olive oil), and polysaccharides (starch, pectin) account for, respectively, 56, 31, and 21% of sea-ice and seawater strains. The temperature dependences for enzyme production during growth and enzymatic activity were determined for two selected enzymes, alpha-amylase and beta-galactosidase. Interestingly, high levels of enzyme productions were measured at growth temperatures between 4 and 10 degrees C, and almost no production was detected at higher temperatures (20-30 degrees C). Catalytic activity was detected even below the freezing point of water (at -5 degrees C), demonstrating the unique properties of these enzymes.
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PMID:Diversity and cold-active hydrolytic enzymes of culturable bacteria associated with Arctic sea ice, Spitzbergen. 1525 24

An additional amylase, besides the typical alpha-amylase, was detected for the first time in the cytoplasm of B. subtilis SUH4-2, an isolate from Korean soil. The corresponding gene (bbmA) encoded a maltogenic amylase (MAase) and its sequence was almost identical to the yvdF gene of B. subtilis 168, whose function was unknown. Southern blot analysis using bbmA as the probe indicated that this gene was ubiquitous among various B. subtilis strains. In an effort to understand the physiological function of the bbmA gene in B. subtilis, the expression pattern of the gene was monitored by measuring the beta-galactosidase activity produced from the bbmA promoter fused to the amino terminus of the lacZ structural gene, which was then integrated into the amyE locus on the B. subtilis 168 chromosome. The promoter was induced during the mid-log phase and fully expressed at the early stationary phase in defined media containing beta-cyclodextrin (beta-CD), maltose, or starch. On the other hand, it was kept repressed in the presence of glucose, fructose, sucrose, or glycerol, suggesting that catabolite repression might be involved in the expression of the gene. Production of the beta-CD hydrolyzing activity was impaired by the spo0A mutation in B. subtilis 168, indicating the involvement of an additional regulatory system exerting control on the promoter. Inactivation of yvdF resulted in a significant decrease of the beta-CD hydrolyzing activity, if not all. This result implied the presence of an additional enzyme(s) that is capable of hydrolyzing beta-CD in B. subtilis 168. Based on the results, MAase encoded by bbmA is likely to be involved in maltose and beta-CD utilization when other sugars, which are readily usable as an energy source, are not available during the stationary phase.
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PMID:Expression of the promoter for the maltogenic amylase gene in Bacillus subtilis 168. 1565 Jun 89

From a mixture of N-acetylglucosaminyl-beta-cyclodextrin (GlcNAc-betaCD) and lactose, beta-D-galactosyl-GlcNAc-betaCD (Gal-GlcNAc-betaCD) was synthesized by the transfer action of beta-galactosidase. GlcNAc-maltotriose (Glc3) and Gal-GlcNAc-Glc3 were produced with hydrolysis of GlcNAc-betaCD by cyclodextrin glycosyltransferase, and Gal-GlcNAc-betaCD by bacterial saccharifying alpha-amylase respectively. Finally, GlcNAc-Glc3-betaCD and Gal-GlcNAc-Glc3-betaCD were synthesized in 5.2% and 3.5% yield when Klebsiella pneumoniae pullulanase was incubated with the mixture of GlcNAc-Glc(3) and betaCD, or Gal-GlcNAc-Glc3 and betaCD respectively. The structures of GlcNAc-Glc3-betaCD and Gal-GlcNAc-Glc3-betaCD were analyzed by FAB-MS and NMR spectroscopy and identified as 6-O-alpha-(6(3)-O-beta-D-N-acetylglucosaminyl-maltotriosyl)-betaCD, and 6-O-alpha-(4-O-beta-D-galactopyranosyl-6(3)-O-beta-D-N-acetylglucosaminyl-maltotriosyl)-betaCD respectively.
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PMID:Synthesis of novel heterobranched beta-cyclodextrins having beta-D-N-acetylglucosaminyl-maltotriose on the side chain. 1584 11

In a 2 x 2 factorial design, 24 newborn, crossbred (Bos indicus x Bos taurus) calves were distributed in 4 equal groups involving dietary treatments of prestarter diets with (FM) or without fish meal (NFM) in a faunated (F) or ciliate-free (D) ruminal environment to study the ruminal fermentative development in pre-and postweaning periods. Defaunation was achieved by rearing calves in isolation and its effect was studied after first appearance of ciliate protozoa (observed after 8 wk of age) in the faunated animals. Calves were fed colostrum for 24 h and whole milk until weaning at 8 wk of age. Ruminal content samples were collected on d 4, 1 wk, weekly to 8 wk, and then biweekly at 9, 11, and 13 wk of age. The samples were analyzed for fermentation products [pH, total volatile fatty acids (VFA) and ammonia N] and enzyme [carboxymethyl (CM) cellulase, xylanase, beta-glucosidase, alpha-amylase, beta-galactosidase, proteases, and urease] activities. Weekly feed intake increased with age, but was similar in both groups. Ruminal pH declined steadily during 0 to 4 wk of age and then stabilized. The total VFA concentration increased with the age. The ammonia N (mg/dL) concentration increased from 14.9 on d 4 to 32.4 at 4 wk, decreased to 17.6 at 8 wk, and then steadied during the postweaning period. Samples collected on d 4 had no fibrolytic activity. Xylanase (U/dL) appeared first (1 wk) followed by beta-glucosidase (U/dL) and CM cellulase (U/dL), which increased steadily from a low of 4.69, 0.08, and 2.95 to 31.8 (6 wk), 5.92 (7 wk), and 19.8 (8 wk), respectively, and the concentrations showed nonsignificant alterations during postweaning periods. The concentration of alpha-amylase (U/dL) increased from 34.3 on d 4 to 87.2 at 8 wk, and then decreased to 56.6 (13 wk). beta-Galactosidase increased up to 6 wk then decreased to trace level (0.20 U/dL) at 13 wk of age. The concentrations of proteases and urease reached a steady state after 1 wk of age. The effect of diet type on ruminal fermentation products and enzyme parameters was nonsignificant. However, a steady and proportional alteration in both parameters in response to dry feed intake with the advancement of age was seen in all calves. Defaunation increased total VFA (97.3 vs. 75.8 mM/L) and alpha-amylase activity (80.3 vs. 61.4 U/dL) and decreased ammonia N (16.4 vs. 21.1 mg/dL), whereas the effect on other parameters was nonsignificant. Ruminal fermentative changes responded to dry feed intake, but did not differ in response to animal protein in prestarter diet.
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PMID:Pre- and postweaning attributes in faunated and ciliate-free calves fed calf starter with or without fish meal. 1590 33


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