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)

A marked breakdown of ribosomes and rRNA occurs in Escherichia coli cells during prolonged deprivation of a carbon source (energy starvation). In E. coli recovering from energy starvation: (a) synthesis of RNA started immediately, total protein synthesis showed a delay of 5 to 10 minutes; (b) beta-galactosidase, tryptophanase and serine deaminase could not be induced in the first 50--70 min; (c) a lag of 60 min in the synthesis of beta-galactosidase was observed in a lac constitutive mutant of E. coli; synthesis of the constitutive enzyme malate dehydrogenase did not shown any delay. RNA synthesized in the early stages of recovery contained a higher percentage of low molecular weight molecules than RNA synthesized after 70 min of recovery or during exponential growth. Messenger RNA specific for beta-galactosidase was not synthesized for the first 50--60 min of recovery even when the specific inducer was added to the cultures.
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PMID:Synthesis of inducible enzyme in Escherichia coli recovering from prolonged energy starvation. 18 24

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

The effect of Fusarium sporotrichiella v. sporotrichioides mycotoxin (sporofusarin) on the total and non-sedimentary supernatant activity of 13 marker-enzymes of subcellular particles (2 mitochondrial enzymes-cytochrome oxidase and malate dehydrogenase; 8 lysosomal enzymes -- acid phosphatase, acid RNAase, acid DNAase, arylsulphatases A and B, beta-N-acetylglucosaminidase, beta-glucuronidase, beta-galactosidase and beta-glucosidase; 2 microsomal enzymes -- glucose-6-phosphatase and acetylesterase; plasma membrane enzyme -- alkaline phosphatase) of the rat liver, kidney, spleen and bone-marrow was studied in in vivo experiments. The latter demonstrated that sporofusarin effects were characterized by a significant organ and organella specificity, viz. the toxin caused a sharply increased activity, mainly of lysosomes enzymes and labilization of the lysosomal membranes, primarily in the spleen and the bone-marrow. A conclusion is drawn that the discovered selective destructive action of sporofusarin on the lysosomes may be regarded as a new phenomenon that, possibly is directly related to the characterization of the mechanism responsible for a specific effect produced by sporofusarin.
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PMID:[Lysosomal component in the mechanism of the toxic effect of sporofusarin]. 94 27

Effect of ethanol on functional activity of isolated perfused rat liver was studied (rate of O2 utilization, absorption of bromosulpholeine from perfusate, bile formation); total activity and activity in supernatant of nine marker enzymes were also determined (malate dehydrogenase, beta-glucuronidase, arylsulphatases A and B, beta-galactosidase, beta-glucosidase, acetylesterase, glucoso-6-phosphatase, alanine aminotransferase and aspartate aminotransferase). Activity of the enzymes was simultaneously studied in perfusate. Ethanol (0.5%) caused distinct impairement in functional activity of isolated liver; rate of bile formation and absorption of bromosulpholeine from perfusate were primarily altered. Degree of impairements in functional activity of liver tissue correlated with the concentration of ethanol in perfusate. In analysis of correlation between the total activity of the enzymes in liver tissue and their activity in supernatants and perfusate it was shown that the concentration (1%) of ethanol used did not produce damaye effect on plasma membranes and membranes of subcellular structures of hepatocytes, but, within certain limits, it displayed a stabilizing effect.
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PMID:[Effect of ethanol on stability of cell membranes in experiments using isolated liver]. 121 Jan 8

An acute toxicological experiment on rats has been performed. During 30 days the animals got nitrates with water and vegetable food. The activity of glucoso-6-phosphatase, malate dehydrogenase, beta-galactosidase, the content of N-acetylneuraminic acid was determined in liver, kidney and blood serum; the level of methemoglobin in blood was estimated. It was found that the changes of studied indexes are less expressed during nitrate introduction with food than with water; on the level of minimum concentrations the changes in non-specific symptom-complex were more expressed. The maximum innocuous intake of nitrates with vegetables is 500 mg in 24 hours taking into consideration the average weight of an individual (50 kg).
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PMID:[Toxicologic evaluation of nitrates entering the body with plant products]. 284 80

The mitochondrial tricarboxylic acid cycle enzyme malate dehydrogenase was purified from Saccharomyces cerevisiae, and an antibody to the purified enzyme was obtained in rabbits. Immunoscreening of a yeast genomic DNA library cloned into a lambda gt11 expression vector with anti-malate dehydrogenase immunoglobulin G resulted in identification of a lambda recombinant encoding an immunoreactive beta-galactosidase fusion protein. The yeast DNA portion of the coding region for the fusion protein translates into an amino acid sequence which is very similar to carboxy-terminal sequences of malate dehydrogenases from other organisms. In s. cerevisiae transformed with a multicopy plasmid carrying the complete malate dehydrogenase gene, the specific activity and immunoreactivity of the mitochondrial isozyme are increased by eightfold. Expression of both the chromosomal and plasmid-borne genes is repressed by growth on glucose. Disruption of the chromosomal malate dehydrogenase gene in haploid S. cerevisiae produces mutants unable to grow on acetate and impaired in growth on glycerol plus lactate as carbon sources.
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PMID:Isolation and expression of the gene encoding yeast mitochondrial malate dehydrogenase. 331 68

Intracellular concentration of cAMP regulates the synthesis of enzymes sensitive to catabolite repression. The relationship between the single and multiple induction of beta-galactosidase (EC 3.2.1.23), L-tryptophanase (EC 4.1.99.1), D-serine deaminase (EC 4.2.1.14), L-asparaginase (EC 3.5.1.1) and L-malate dehydrogenase (EC 1.1.1.37) was studied and the effect of cAMP level on the induction in Escherichia coli Crookes (ATCC 8739) was investigated. A varying degree of catabolite repression was observed during induction of individual enzymes induced separately on different energy sources. The synthesis of l-tryptophanase was most sensitive, whereas l-asparaginase was not influenced at all. Exogenous cAMP was found to overcome partially the catabolite repression of beta-galactosidase and D-serine deaminase, both during single induction. The synthesis of l-malate dehydrogenase was negatively influenced by the multiple induction even in the presence of cAMP; on the other hand, the synthesis of l-tryptophanase was stimulated, independently of the level of the exogenous cAMP. Similarly, the activity of L-asparaginase slightly but significantly increased during the multiple induction of all five enzymes; here too the activity increase did not depend on exogenous cAMP.
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PMID:Catabolite repression during single and multiple induction in Escherichia coli. 625 31

We have determined the subcellular localization of an endopeptidase activity able to degrade gonadotropin releasing hormone (GnRH) and present in the rat adenohypophysis. After fractionation of tissue homogenates in 0.25 M sucrose by differential centrifugation, about 25% of the total cellular GnRH degrading activity was found to be sedimentable and recovered from heavy (M) and light (L) mitochondrial fractions with a distribution pattern similar to that of the mitochondrial and lysosomal reference enzymes cytochrome oxidase and beta-galactosidase. Upon further fractionation on sucrose density gradients, the activity comigrated with mitochondria. The peptidase appears endowed with a structure-linked latency; the activity is low in a freshly prepared mitochondrial fraction and increases upon treatment with membrane disrupting agents in a manner similar to that of malate dehydrogenase, a component of the mitochondrial matrix. Determination of GnRH cleavage sites was performed by amino acid analysis of the fragments obtained after incubation of the peptidase with (3H)-GnRH labelled on the pyroglutamic acid residue, in presence of carboxypeptidase and peptidyldipeptidase inhibitors. The fragments were separated by ion-exchange chromatography on an Aminex Q-15S column and purified by chromatography on silica gel plates. Fragments 1-2, 1-3, 1-4, 1-5 and 1-6 were all present as early as 1 min after the beginning of incubation. Formation of each of them was inhibited to the same extent by EDTA, mersalyl acid, dithioerythritol and Na deoxycholate. The same fragmentation pattern was observed after partial purification of the enzyme by gel filtration. These data indicate that cleavage of several peptide bonds may result from a possibly single endopeptidase located in the mitochondrial matrix space.
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PMID:Characterization of a neutral endopeptidase localized in the mitochondrial matrix of rat anterior pituitary tissue with GnRH as a substrate. 637 12

Stability of mitochondrial and lysosomal membranes was studied in growing rats under conditions of hypervitaminosis A. The membrane stability was evaluated by the rate of solubilization of marker mitochondrial enzyme--malate dehydrogenase, and of lysosomal enzyme--beta-galactosidase, using incubation of the isolated organelles with gradually increasing concentrations of Triton X-100. High doses of vitamin A did not affect the total activity of the enzymes studied but distinctly increased the rate of malate dehydrogenase and beta-galactosidase solubilization, caused by Triton X-100, as compared with controls. This suggests the increase in sensitivity of the organelle membranes to the effect of Triton X-100 in the hypervitaminosis A, which is apparently related to pronounced impairment of the membrane structure.
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PMID:[Mitochondrial and lysosomal membrane stability following administration of excessive doses of vitamin A in vivo]. 677 19

The authors studied combined effect of aniline (20 mg/kg for a period of 4 weeks in drinking water) and nitrosodimethylamine (NDMA) (30 mg/kg, a single intragastric dose) on the activity of enzymes of different subcellular structures: endoplasmic reticulum (cytochromes P450, B5, acetylesterase), mitochondria (malate dehydrogenase) and the content of N-acetylneuraminic acid in rat liver and of lysosomes (beta-glucuronidase, beta-galactosidase). The combined action of NDMA and aniline was accompanied by more pronounced changes in the indices under investigation than isolated administration of the given chemical substances. The most pronounced aggravation of the unfavourable changes was observed in the activity of enzymes connected with the processes of oxidation and energy supply to the cell (malate dehydrogenase) and the metabolism of glucuronides (beta-glucuronidase) as well as in the content of N-acetylneuraminic acid. This may be connected with the modifying effect of aniline on the toxic effect of NDMA.
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PMID:Combined effect of nitrosodimethylamine and aniline on the enzyme systems of subcelluar structures. 680 54


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