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)

The fumarase gene (citG) of Bacillus subtilis is transcribed from two promoter regions, citGp1 and citGp2 (P1 and P2); the P2 promoter is used by the E sigma H form of RNA polymerase. In order to study the role of P1 and P2 in citG expression, the promoter region and various deletion derivatives that effectively separate P1 and P2 were fused to the Escherichia coli beta-galactosidase gene (lacZ) and introduced into the chromosome in single copy at the amyE locus. P1 functioned to provide a relatively low and stable basal level of fumarase activity throughout growth. In contrast, P2 activity was found to vary over at least a 50-fold range and was responsible for regulating fumarase activity during growth and sporulation in a rich medium and in response to changes in carbon source. To further investigate the role of sigma H in fumarase regulation, citGp2-lacZ fusions were introduced into a strain in which the expression of the chromosomal spoOH gene was under the control of the isopropylthiogalactopyranoside-inducible spac promoter. Induction of pspac did not lead to P2 induction, suggesting that citG expression is not regulated at the level of spoOH transcription.
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PMID:Role of sigma H in expression of the fumarase gene (citG) in vegetative cells of Bacillus subtilis 168. 250 23

The binding sites in fibrinogen for Factor XIII were localized using an immunoblotting technique. Platelet Factor XIII bound to fibrinogen and to plasmin degradation products of fibrin(ogen) including Fragments: X, D1-D3, and D-dimer, but did not bind to Fragment E. Binding of Platelet Factor XIII was independent of calcium ions but could be inhibited by the presence of 0.5 M NaCl. Binding could also be inhibited by preincubating Factor XIII with a 100-fold molar excess of fibrinogen but not by 100-fold molar excess of Fragment E. Binding of Factor XIII to fibrinogen was specific, since several other proteins tested (ovalbumin, bovine serum albumin, alpha 2-macroglobulin, beta-galactosidase, fructose kinase, lactic dehydrogenase, triose phosphate isomerase, fumarase and pyruvate kinase) did not bind Factor XIII. Furthermore, binding was not observed either when Factor XIII was left out or when antiFactor XIII antiserum was substituted with nonimmune serum. When fibrinogen was reduced prior to electrophoresis, Factor XIII bound to the A alpha and B beta chains of fibrinogen and des A,B fibrinogen, the B beta-chain of Fragment X, but not the gamma-chains. Localization of the Factor XIII binding sites to the carboxy terminal segments of the A alpha and B beta chains in the Fragment D-domain of fibrinogen could have important physiological consequences.
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PMID:Factor XIII binds to the A alpha- and B beta- chains in the D-domain of fibrinogen: an immunoblotting study. 295 7

The activities of acid phosphatase, hexosaminidase, beta-galactosidase, Mg2+-stimulated Na+K+ATPase, fumarase and ATP:citrate lyase were measured in grey matter of rabbit spinal cord 7-8 days after intra-ventricular or intra-cisternal injection of aluminium. RNA, DNA, and water content were measured in whole spinal cords. Choline acetyltransferase (CAT) and acetylcholinesterase were assayed in dorsal grey matter of the cord, which contained no aluminium-induced neurofilament accumulations (NFAs), and ventral grey matter, which had large numbers of such NFAs. CAT was also assayed in the hypoglossal nerve. None of these measures were consistently altered in the aluminium treated rabbits, although the activity of beta-galactosidase was increased in the NFA-free caudate nucleus of rabbits given aluminium intra-ventricularly, possibly due to the presence of phagocytes on the ventricular surface of the caudate. It is concluded that neither aluminium nor its induced NFAs has a gross effect on neuronal metabolism within 7-8 days.
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PMID:Biochemical studies on rabbits with aluminium induced neurofilament accumulations. 298 21

Acetohydroxy acid synthetase, which is sensitive to catabolite repression in wild-type Escherichia coli B, was relatively resistant to this control in a streptomycin-dependent mutant. The streptomycin-dependent mutant was found to be inducible for beta-galactosidase in the presence of glucose, although repression of beta-galactosidase by glucose occurred under experimental conditions where growth of the streptomycin-dependent mutant was limited. Additional glucose-sensitive enzymes of wild-type E. coli B (citrate synthase, fumarase, aconitase and isocitrate dehydrogenase) were found to be insensitive to the carbon source in streptomycin-dependent mutants: these enzymes were formed by streptomycin-dependent E. coli B in equivalent quantities when either glucose or glycerol was the carbon source. Two enzymes, glucokinase and glucose 6-phosphate dehydrogenase, that are glucose-insensitive in wild-type E. coli B were formed in equivalent quantity on glucose or glycerol in both streptomycin-sensitive and streptomycin-dependent E. coli B. The results indicate a general decrease or relaxation of catabolite repression in the streptomycin-dependent mutant. The yield of streptomycin-dependent cells from glucose was one-third less than that of the streptomycin-sensitive strain. We conclude that the decreased efficiency of glucose utilization in streptomycin-dependent E. coli B is responsible for the relaxation of catabolite repression in this mutant.
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PMID:Relaxation of catabolite repression in streptomycin-dependent Escherichia coli. 497 19

When a wild-type strain of Escherichia coli B was cultured on a medium containing L-aspartic acid as the sole carbon source (Asp-C medium), aspartase formation was higher than that observed in minimal medium. Addition of glucose to Asp-C medium decreased aspartase formation. When also cultured in a medium containing L-aspartic acid as the sole nitrogen source (Asp-N medium), E. coli B showed a low level of aspartase formation and an elongated doubling time. To obtain aspartase-hyperproducing strains, we enriched cells growing faster than cells of the wild-type strain in Asp-N medium by continuous cultivation of mutagenized cells. After plate selection, the doubling times of these mutants were measured. Thereafter, fast-growing mutants were tested for aspartase formation. One of these mutants, strain EAPc7, had a higher level of aspartase formation than did the wild-type strain in medium containing L-aspartic acid as the carbon source, however; addition of glucose to this medium decreased aspartase formation. The other mutant, strain EAPc244, had a higher level of aspartase activity than did the wild-type strain in both media. Therefore, aspartase formation in mutant EAPc244 was released from catabolite repression. In strain EAPc244 the other catabolite-repressible enzymes, beta-galactosidase, tryptophanase, and the three tricarboxylic acid cycle enzymes, were also released from catabolite repression. Both mutants had sevenfold the aspartase formation of the wild-type strain in a medium which contained fumaric acid as the main carbon source and which has been used for industrial production of E. coli B aspartase. However, strain EAPc244 had 2.5-fold the fumarase activity of strain EAPc7.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Aspartase-hyperproducing mutants of Escherichia coli B. 639 73

This immunological study involved individual injection of the three Schistosoma mansoni antigens (Ags). soluble egg antigen (SEA), cercarial antigen preparation (CAP) or soluble worm antigen preparation (SWAP) in three rabbits groups (Ag). respectively. Three other groups each received the same specific antigen conjoined with administration of L-carnosine (Ag-C). Determination of three hepatic parameters and ten serum proteins was done. These were total protein, glycogen content and glycogen phosphorylase b activity of liver as well as serum total protein and nine protein fractions [alpha2-macrglobulin; beta-galactosidase; phosphorylase b; serum albumin; fumarase; carbonic anhydrase; beta-lactoglobulin; alpha-lactalbumin and aprotinin]. Conjoined carnosine treatment produced numerous variations. SEA-I-C group presented sex decreased parameters. In CAP-I-C animals hepatic glycogen content was increased while phosphorrylase b activity was decreased as well as seven the concentration of serum parameters; total serum protein, alpha2-macroglobulin, phosphorylase b, albumin, fumarase, carbonic anhydrase, alpha-lactalbumin and aprotinin. In SWAP-I-C group the concentration of only one fraction was decreased; carbonic anhydrase. In batch A both the Ags. of the egg and cercaria, developmental stages having transient residence in the animal host, showed more affection by the specific Ag. Although, carnosine modified the results of all the three groups in batch B yet, its effect on both the egg and cercaria Ags. was still more than that of worm.
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PMID:Biochemical modifications induced in rabbits by Schistosoma mansoni antigens and the beneficial effect of carnosine treatment. 1588 Oct 9

Hierarchical control ensures that facultative bacteria preferentially use the available respiratory electron acceptor with the most positive standard redox potential. Thus, nitrate is used before other electron acceptors such as fumarate for anaerobic respiration. Nitrate regulation is mediated by the NarX-NarL two-component system, which activates the transcription of operons encoding nitrate respiration enzymes and represses the transcription of operons for other anaerobic respiratory enzymes, including enzymes involved in fumarate respiration. These are fumarate reductase (encoded by the frdABCD operon), fumarase B, which generates fumarate from malate, and the DcuB permease for fumarate, malate, and aspartate. The transcription of the corresponding structural genes is activated by the DcuS-DcuR two-component system in response to fumarate or its dicarboxylate precursors. We report results from preliminary transcription microarray experiments that revealed two previously unknown members of the NarL regulon: the aspA gene encoding aspartate-ammonia lyase, which generates fumarate; and the dcuSR operon encoding the dicarboxylate-responsive regulatory system. We measured beta-galactosidase expression from monocopy aspA-lacZ, frdA-lacZ, and dcuS-lacZ operon fusions in response to added nitrate and fumarate and with respect to the dcuR and narL genotypes. Nitrate, acting through the NarX-NarL regulatory system, repressed the transcription of all three operons. Only frdA-lacZ expression, however, was responsive to added fumarate or a dcuR(+) genotype. Phospho-NarL protein protected operator sites in the aspA and dcuS promoter regions from DNase I cleavage in vitro. The overall results are consistent with the hypothesis that nitrate represses frdA operon transcription not only directly, by repressing frdA promoter activity, but also indirectly, by repressing dcuS promoter activity.
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PMID:Hierarchical control of anaerobic gene expression in Escherichia coli K-12: the nitrate-responsive NarX-NarL regulatory system represses synthesis of the fumarate-responsive DcuS-DcuR regulatory system. 1599 4

There are a growing number of proteins which are reported to reside in multiple compartments within the eukaryotic cell. However, lack of appropriate methods limits our knowledge on the true extent of this phenomenon. In this study, we demonstrate a novel application of beta-galactosidase alpha-complementation to study dual distribution of proteins in yeast cells. Using a simple colony color phenotype, we show that alpha-complementation depends on co-compartmentalization of alpha and omega fragments and exploit this to probe dual localization of proteins between the cytosol and mitochondria in yeast. The quality of our assay was assessed by analysis of the known dual targeted enzyme fumarase and several mutant derivatives, which are exclusively localized to one or the other of these subcellular compartments. Addition of the alpha fragment did not abolish the enzymatic activity of the tagged proteins nor did it affect their localization. By examining 10 yeast gene products for distribution between the cytosol and the mitochondria, we demonstrate the potential of alpha-complementation to screen the mitochondrial proteome for dual distribution. Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria.
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PMID:Alpha-complementation as a probe for dual localization of mitochondrial proteins. 1703 89