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)

Polyclonal antibodies to Escherichia coli beta-galactosidase, beta-glucuronidase, and glutamate decarboxylase were used in coagglutination tests for identification of these three enzymes in cell lysates. Enzyme capture assays were also developed for the detection of E. coli beta-galactosidase and beta-glucuronidase. The enzymes were released by using a gentle lysis procedure that did not interfere with antibody-enzyme interactions. All three enzymes were detected in 93% (51 of 55) of the E. coli strains tested by coagglutination; two of the three enzymes were identified in the remaining 7%. Of 42 non-E. coli tested by coagglutination, only four nonspecifically agglutinated either two or three of the anti-enzyme conjugates. Thirty-two (76%) non-E. coli isolates were negative by coagglutination for all three enzymes. The enzyme capture assay detected the presence of beta-galactosidase in seven of eight and beta-glucuronidase in all eight strains of E. coli tested. Some strains of beta-galactosidase-positive Citrobacter freundii and Enterobacter cloacae were also positive by the enzyme capture assay, indicating that the antibodies were not entirely specific for E. coli beta-galactosidase; however, five other gas-positive non-E. coli isolates were negative by the enzyme capture assay. The coagglutination tests and enzyme capture assays were rapid and sensitive methods for the detection of E. coli beta-galactosidase, beta-glucuronidase, and glutamate decarboxylase.
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PMID:Coagglutination and enzyme capture tests for detection of Escherichia coli beta-galactosidase, beta-glucuronidase, and glutamate decarboxylase. 311 64

Glutamate decarboxylase (GAD; E.C. 4.1.1.15) converts glutamate to gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the vertebrate central nervous system. This report describes the isolation of a GAD complementary DNA clone by immunological screening of a lambda gt-11 brain complementary DNA expression library. The fusion protein produced by this clone catalyzes the conversion of glutamate to GABA and carbon dioxide, confirming its identity as GAD. Antibodies to beta-galactosidase remove GAD enzymatic activity from solution, showing that this activity is associated with the fusion protein. In immunoblotting experiments all three available antisera to GAD reacted with the fusion polypeptide and with two major polypeptides (molecular size, 60,000 and 66,000 daltons) in brain extracts.
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PMID:Brain glutamate decarboxylase cloned in lambda gt-11: fusion protein produces gamma-aminobutyric acid. 351 61

We have investigated developmental changes in activity for five enzymes associated with different cerebral metabolic systems in two separate strains of mice. The enzymes studied were acid beta-galactosidase, arylsulfatase A, cerebroside beta-galactosidase, cerebroside sulfotransferase, and glutamate decarboxylase. The two strains of mice were C3H/SWV and ICR/SWV. We confirm the experiments of Meisler, Paigen, and colleagues showing higher acid beta-galactosidase activity throughout development in C3H mice. In addition we have demonstrated higher arylsulfatase A activity throughout development in C3H mice. The shape of the developmental curve for arylsulfatase A activity in brain in the two strains was similar. There were no differences in developmental changes of activity between the two strains for the other three enzymes studied.
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PMID:Genetic control of developmental patterns of cerebral enzyme activities: further differences between C3H and ICR strains of mice. 611 39

We have found that the upstream region of the isocitrate lyase gene (UPR-ICL) from the n-alkane-utilizing yeast Candida tropicalis was functional in Saccharomyces cerevisiae as a novel promoter with nonfermentable carbon sources, such as oleic acid, acetate, ethanol, and glycerol/lactate. The expression of two foreign genes coding for beta-galactosidase from Escherichia coli (LacZ) and glutamate decarboxylase from rat brain was carried out under the control of UPR-ICL. Expression of LacZ was repressed by glucose and enhanced over 300-fold by acetate. When an expression vector pWI3 containing multicloning sites between UPR-ICL and the transcriptional terminator of the isocitrate lyase gene (TERM-ICL) was used, the smaller isoform of glutamate decarboxylase (GAD65) was highly produced in a soluble and active form. These results demonstrate that the novel expression system using UPR-ICL and TERM-ICL from C. tropicalis is useful for the production of heterologous proteins in S. cerevisiae.
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PMID:A novel heterologous gene expression system in Saccharomyces cerevisiae using the isocitrate lyase gene promoter from Candida tropicalis. 886 34

Calcium-binding proteins (CaBPs) are a family of proteins having a unique distribution in the brain and are thought to be important in buffering intracellular calcium. Glutamate neurotoxicity is a process by which the over-activation of glutamate receptors can cause the influx of excessive extracellular calcium and neuronal cell death. It has been proposed that neurons containing CaBP may be more resistant to glutamate neurotoxicity due to their increased ability to buffer calcium. Using a herpes simplex virus-1 (HSV-1) vector system we packaged the CaBP gene, parvalbumin, or the marker gene, beta-galactosidase (beta-gal), correctly in viron particles, which were found upon infection to express mRNA specific to these vectors. PC12 and neocortical cultures showed strong immunohistochemical staining for either beta-gal or parv. The cortical cultures stained positively for endogenous glutamate decarboxylase, a marker for GABAergic neurons, but not for endogenous parvalbumin, indicating that parvalbumin was being expressed ectopically from the HSV-1 vector. Interestingly, the expression of parvalbumin increased cortical culture's susceptibility to N-methyl-D-aspartate-induced neurotoxicity. This increase in neurotoxicity was not due to the wild-type virus or the helper virus which accompanies the packaging of these vectors. We speculate that the ectopic expression of parvalbumin in cortical cultures may be increasing glutamate release which in turn increases cell death.
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PMID:Expression of the calcium-binding protein, parvalbumin, in cultured cortical neurons using a HSV-1 vector system enhances NMDA neurotoxicity. 887 13

D-Cycloserine is an effective second-line drug against Mycobacterium avium and Mycobacterium tuberculosis. To analyze the genetic determinants of D-cycloserine resistance in mycobacteria, a library of a resistant Mycobacterium smegmatis mutant was constructed. A resistant clone harboring a recombinant plasmid with a 3.1-kb insert that contained the glutamate decarboxylase (gadA) and D-alanine racemase (alrA) genes was identified. Subcloning experiments demonstrated that alrA was necessary and sufficient to confer a D-cycloserine resistance phenotype. The D-alanine racemase activities of wild-type and recombinant M. smegmatis strains were inhibited by D-cycloserine in a concentration-dependent manner. The D-cycloserine resistance phenotype in the recombinant clone was due to the overexpression of the wild-type alrA gene in a multicopy vector. Analysis of a spontaneous resistant mutant also demonstrated overproduction of wild-type AlrA enzyme. Nucleotide sequence analysis of the overproducing mutant revealed a single transversion (G-->T) at the alrA promoter, which resulted in elevated beta-galactosidase reporter gene expression. Furthermore, transformants of Mycobacterium intracellulare and Mycobacterium bovis BCG carrying the M. smegmatis wild-type alrA gene in a multicopy vector were resistant to D-cycloserine, suggesting that AlrA overproduction is a potential mechanism of D-cycloserine resistance in clinical isolates of M. tuberculosis and other pathogenic mycobacteria. In conclusion, these results show that one of the mechanisms of D-cycloserine resistance in M. smegmatis involves the overexpression of the alrA gene due to a promoter-up mutation.
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PMID:Overexpression of the D-alanine racemase gene confers resistance to D-cycloserine in Mycobacterium smegmatis. 926 Sep 45

GABA is synthesized by glutamate decarboxylase (GAD), which has two forms, GAD65 and GAD67. To elucidate the molecular mechanisms of mouse GAD65 (mGAD65) gene expression, we isolated and characterized the mGAD65 gene. The mGAD65 gene was found to be divided into 16 exons and spread over 75 kb. The sequence of the first exon and the 5'-flanking region indicated the presence of potential neuron-specific cis-regulatory elements. We used transgenic mice to examine the expression pattern conferred by a 9.2-kb promoter-proximal DNA fragment of the mGAD65 gene fused to the bacterial lacZ reporter gene. Transgenic mice showed high beta-galactosidase activity specifically in brain and testis. They also showed characteristic patterns of transgene expression in olfactory bulb, cerebellar cortex, and spinal cord, a similar expression pattern to that of endogenous mGAD65. However, no transgene expression was observed in the ventral thalamus or hypothalamus, in which high mGAD65 gene expression levels have been observed. These results suggest that the 9.2-kb DNA fragment of the mGAD65 gene is associated with its tissue-specific expression and its targeted expression in GABAergic neurons of specific brain regions but that additional regulatory elements are necessary to obtain fully correct expression.
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PMID:Structure of the mouse glutamate decarboxylase 65 gene and its promoter: preferential expression of its promoter in the GABAergic neurons of transgenic mice. 1098 22