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)

Eschscholtzia californica stigmas with germinating pollen at different stages of development were the subject of histochemical studies which aimed the localization of several enzymes like phosphorylase, leucine amino peptidase, nonspecific esterase, cytochrome oxidase, aldolase, alpha-glycerophosphate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, monoamine oxidase, alpha-galactosidase, beta-glucosidase and beta-galactosidase. Pollen and pollen tubes were shown to contain starch, lipid, proteins and soluble sugars as the storage products. These storage products were utilized during germination and tube growth. The role of different enzymes in the process of germination and tube growth is discussed. From the distribution of oxidoreductases it is inferred that respiration plays an essential role in the tube growth. During pollen germination probably the reserve proteins were transported to pollen tube tip. The increase of activity of alpha-and beta-galactosidase in pollen tubes indicates on their involvement in carbohydrate metabolism. The role of alpha-galactosidase in the metabolism of galactolipids is also inferred. Similarly, the reaction catalysed by beta-glucosidase resulted in the production of aglycon and glucose; of these the former possibly act as a substrate of peroxidase. Some of the glycosidases diffused out of pollen wall on the stigma and participated in the release of free sugars of the female tissue.
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PMID:Studies on the physiology of pollen and pollen tube growth. IV Eschscholtzia californica Cham. 22 Jan 58

We report the construction of an inducible, high-copy plasmid for the expression of foreign proteins in Escherichia coli. This plasmid, pPB1, combines the trc promoter, beta-galactosidase translation start site, and polylinker of pKK233-2 with the origin of replication region of pUC19. Replacement of the origin of replication of pKK233-2 results in a threefold increase in plasmid copy number of pPB1 compared with pKK233-2. Subclones of the cDNA for rabbit muscle fructose-1,6-bisphosphate aldolase (E.C. 4.1.2.13) in the two expression plasmids exhibit a comparable difference in copy number. An increase in protein expression measured by SDS-PAGE and aldolase specific activities reflects the increased copy number. Specific activities of aldolases in bacterial extracts differ approximately sixfold between the two expression plasmids in E. coli JM83. Aldolase A can compose up to 40% of the total protein in E. coli JM83 when expressed in pPB1, from which more than 100 mg of purified enzyme can be obtained per liter culture.
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PMID:Construction of a high-copy "ATG vector" for expression in Escherichia coli. 142 27

Defective transducing phages carrying aroG, the structural gene for phenylalanine (phe)-inhibitable phospho-2-keto-heptonate aldolase (EC 4.1.2.15; previously known as 3-deoxy-D-arabinoheptulosonate-7-phosphate synthetase[phe]), have been isolated, and DNA from two of these phages has been used to construct a restriction map of the region from att lambda to aroG. A 7.6-kb PstI-HindIII fragment from one of these phages was cloned into pBR322 and shown to contain aroG. The location of aroG within the 7.6 kb was established by subcloning and Tn3 transpositional mutagenesis. A fragment carrying the aroG promoter and operator has been cloned into a high copy number promoter-cloning vector (pMC489), and the resulting aroGpo-LacZ' (alpha) fusion subcloned in a low copy number vector. Strains with this fusion on the low copy number vector exhibit negative regulation of beta-galactosidase expression by both phenylalanine and tryptophan and positive regulation by tyrosine in a tyrR+ background.
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PMID:Cloning of aroG, the gene coding for phospho-2-keto-3-deoxy-heptonate aldolase(phe), in Escherichia coli K-12, and subcloning of the aroG promoter and operator in a promoter-detecting plasmid. 286 Nov 43

Several streptomycin-resistant mutants of Escherichia coli have been isolated which require exogenous isoleucine for growth. The majority of these strains were of streptomycin-dependent phenotype. If grown in the absence of streptomycin, these streptomycin-dependent auxotrophs (Sm(d-aux)) strains were unable to produce beta-galactosidase and aldolase activities and also failed to exhibit donor properties in conjugation. Genetic analysis indicated that the isoleucine requirement of these strains could be caused by a mutation at the strA locus.
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PMID:Development of auxotrophy by streptomycin-resistant mutation. 459 98

Subacute experiments were made to examine the effect of the grain contaminated with Fusarium sporotrichiella on the activity of organelle-specific enzymes of the liver, thymus, spleen, bone marrow and blood serum of rats (beta-N-acetylglucosaminidase, alpha-mannosidase, beta-galactosidase, arylsulfatases A and B, succinate dehydrogenase, glucose-6-phosphatase, alkaline phosphatase, ketoso-1-phosphate aldolase) and on the protein content. The feeding of the grain provoked an early appearance of the symptoms of intoxication and a change in the activity of organelle-specific enzymes manifesting in the activation of lysosomal hydrolases in the thymus, bone marrow and spleen and in a decrease in the blood serum activity of the most enzymes investigated.
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PMID:[Enzyme characteristics of food poisoning caused by grain contaminated with Fusarium sporotrichiella]. 642 31

Efficient expression of a foreign gene requires a stable vector present at a high number of copies per cell. We have constructed an autoselection system for the stable maintenance of expression vector in the yeast Saccharomyces cerevisiae that uses the fructose 1,6-bisphosphate aldolase gene (FBA1) to stabilize plasmids in cells bearing a disruption of the chromosomal FBA1 gene. This system allowed us to obtain stable production of a reporter heterologous enzyme (Escherichia coli beta-galactosidase) in rich media. By using an inducible promoter to regulate the expression of FBA1 gene, we have also obtained the modulation of plasmid copy number by carbon source.
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PMID:Copy number modulation in an autoselection system for stable plasmid maintenance in Saccharomyces cerevisiae. 776 48

The pregnant rats were treated with formaldehyde (0.5 mg/kg daily per os) during whole period of pregnancy. The activity of cytochrome-c-oxidase, malate dehydrogenase, nucleotidase, glucose-6-phosphatase, beta-glucuronidase, N-acetyl-beta-glucosaminidase, beta-galactosidase, H(+)-ATPase, glutamate dehydrogenase, NAD- and NADP-isocitrate dehydrogenase, fructose-bisphosphate aldolase, glucose-6-phosphate dehydrogenase and content of protein in liver celts of offsprings (newborns, 2 weeks age and 2 months age) were studied. It was shown differences in development enzyme systems of control and experimental animals during ontogenesis.
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PMID:[Experimental study of the effect of formaldehyde during embryogenesis on the activity of rat liver enzyme systems in ontogenesis]. 913 53

Aldolase C is regarded as the brain-specific form of fructose-1, 6-bisphosphate aldolase whereas aldolase A is regarded as muscle-specific. In situ hybridization of mouse central nervous system using isozyme-specific probes revealed that aldolase A and C are expressed in complementary cell types. With the exception of cerebellar Purkinje cells, aldolase A mRNA is found in neurons; aldolase C message is detected in astrocytes, some cells of the pia mater, and Purkinje cells. We isolated aldolase C genomic clones that span the entire protein coding region from 1.5 kb 5' to the transcription start site to 0.5 kb 3' to the end of the last exon. The bacterial gene, lacZ, was inserted in two different locations and the constructs tested in transgenic mice. When the protein coding sequences were replaced with lacZ, three of five transgenic lines expressed beta-galactosidase only in cells of the pia mater; one line also expressed in astrocyte-like cells. When lacZ was inserted into the final exon (and all structural gene sequences were retained) transgene expression was observed in astrocytes in all regions of the central nervous system as well as in pial cells. Thus, with the exception of Purkinje cell expression, the behavior of the full-length transgene mimics the endogenous aldolase C gene. The results with the shorter transgene suggest that additional enhancer elements exist within the intragenic sequences. The absence of Purkinje cell staining suggests that the cis elements required for this expression must be located outside of the sequences used in this study.
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PMID:Genomic sequences of aldolase C (Zebrin II) direct lacZ expression exclusively in non-neuronal cells of transgenic mice. 948 35

Studies of gene expression in haloarchaea have been greatly hindered by the lack of a convenient reporter gene. In a previous study, a beta-galactosidase from Haloferax alicantei was purified and several peptide sequences determined. The peptide sequences have now been used to clone the entire beta-galactosidase gene (designated bgaH) along with some flanking chromosomal DNA. The deduced amino acid sequence of BgaH was 665 amino acids (74 kDa) and showed greatest amino acid similarity to members of glycosyl hydrolase family 42 [classification of Henrissat, B., and Bairoch, A. (1993) New families in the classification of glycosyl hydrolases based on amino acid sequence similarities. Biochem J 293: 781-788]. Within this family, BgaH was most similar (42-43% aa identity) to enzymes from extremely thermophilic bacteria such as Thermotoga and Thermus. Family 42 enzymes are only distantly related to the Sulfolobus LacS and Escherichia coli LacZ enzymes (families one and two respectively). Three open reading frames (ORFs) upstream of bgaH were readily identified by database searches as glucose-fructose oxidoreductase, 2-dehydro-3-deoxyphosphogluconate aldolase and 2-keto-3-deoxygluconate kinase, enzymes that are also involved in carbohydrate metabolism. Downstream of bgaH there was an ORF which contained a putative fibronectin III motif. The bgaH gene was engineered into a halobacterial plasmid vector and introduced into Haloferax volcanii, a widely used strain that lacks detectable beta-galactosidase activity. Transformants were shown to express the enzyme; colonies turned blue when sprayed with Xgal and enzyme activity could be easily quantitated using a standard ONPG assay. In an accompanying publication, Patenge et al. (2000) have demonstrated the utility of bgaH as a promoter reporter in Halobacterium salinarum.
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PMID:Sequence and expression of a halobacterial beta-galactosidase gene. 1076 Jan 68

When fed to a beta-galactosidase-negative (lacZ(-)) Escherichia coli strain that was grown on an alternative carbon source (such as glycerol), lactose accumulated intracellularly on induction of the lactose permease. We showed that intracellular lactose was efficiently glycosylated when genes of glycosyltransferase that use lactose as acceptor were expressed. High-cell-density cultivation of lacZ(-) strains that overexpressed the beta 1,3 N acetyl glucosaminyltransferase lgtA gene of Neisseria meningitidis resulted in the synthesis of 6 g x L(-1) of the expected trisaccharide (GlcNAc beta 1-3Gal beta 1-4Glc). When the beta 1,4 galactosyltransferase lgtB gene of N. meningitidis was coexpressed with lgtA, the trisaccharide was further converted to lacto-N-neotetraose (Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc) and lacto-N-neoheaxose with a yield higher than 5 g x L(-1). In a similar way, the nanA(-) E. coli strain that was devoid of NeuAc aldolase activity accumulated NeuAc on induction of the NanT permease and the lacZ(-) nanA(-) strain that overexpressed the N. meningitidis genes of the alpha2,3 sialyltransferase and of the CMP-NeuAc synthase efficiently produced sialyllactose (NeuAc alpha 2-3Gal beta 1-4Glc) from exogenous NeuAc and lactose.
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PMID:A new fermentation process allows large-scale production of human milk oligosaccharides by metabolically engineered bacteria. 1204 46


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