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)

Streptozotocin treatment (125 mg/kg) in the Chinese hamster induced hyperglycaemia, hypoinsulinaemia, hyperglucagonaemia and changes in body, liver, pancreas, stomach, kidney and adipose tissue weights. The pancreatic reserves of insulin and glucagon in the diabetic animals were low, but stomach glucagon high. These animals showed high levels of phosphoenolpyruvate carboxykinase and low levels of glucokinase, hexokinase, isocitrate dehydrogenase and malic enzyme, but normal levels of pyruvate kinase in the liver. Increases in lactate dehydrogenase subunit B and isozymes 2, 3 and 4 were also observed in the liver, but not in the epididymal fat pad, of the diabetic animals. N-Acetyl-beta-D-glucosaminidase was elevated in plasma, liver and heart, but not in the kidney of the treated animals. Renal alpha-galactosidase and beta-glucosidase were depressed, whereas beta-galactosidase and alpha-glucosidase remained essentially normal. These features indicated that there were considerable differences between the biochemical disorders associated with streptozotocin-diabetes in the Chinese hamster and the published observations in the rat.
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PMID:Streptozotocin-induced diabetes in the Chinese hamster. Biochemical and endocrine disorders. 59 Jun 51

To examine the role of primary amino acid sequence in the localization of proteins within the nucleus, we studied the nucleolar protein NO38 of amphibian oocytes. We synthesized NO38 transcripts in vitro, injected them into the oocyte cytoplasm, and followed the distribution of the translation products. The injected RNA contained a short sequence encoding an epitope derived from the human c-myc protein. We used an mAb against this epitope to detect translation products from injected RNAs by Western blots and by immunofluoresent staining of cytological preparations. When full-length transcripts of NO38 were injected into oocytes, the translation products accumulated efficiently in the germinal vesicle, and a major fraction was localized in the multiple nucleoli. To identify protein domains involved in this nucleolus-specific accumulation, we prepared a series of carboxy-terminal deletions of the cDNA. Oocytes injected with RNA encoding truncated forms of NO38 were examined for altered patterns of protein accumulation. We defined a domain of about 24 amino acids near the carboxy terminus that was essential for nucleolar localization of NO38. This domain is separated by more than 70 amino acids from two putative nuclear localization signals near the middle of the molecule. Hybrid constructs were made which encoded part of Escherichia coli beta-galactosidase or pyruvate kinase fused to a long segment of NO38 containing the essential domain. Injection of RNA from these constructs showed that the essential domain was not sufficient to target the hybrid proteins to the nucleolus. We suggest that nucleolar accumulation of NO38 requires more than a single linear domain.
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PMID:Localization of the nucleolar protein NO38 in amphibian oocytes. 173 Jul 39

We have investigated the topography of a glycosyl-phosphatidylinositol implicated in insulin action by a combination of two complementary methods: (a) chemical labelling with a non-permeable (isethionyl acetimidate) and a permeable (ethyl acetimidate) probe; and (b) enzymatic modifications with beta-galactosidase (EC 3.2.1.23) or phosphatidylinositol-specific phospholipase C (EC 3.1.4.3). Using the first approach the majority of the glycosyl-phosphatidylinositol is found in the outer surface of intact hepatocytes, adipocytes, fibroblasts and lymphocytes, but not in erythrocytes which presented only a 20% of the total labelled glycosyl-phosphatidylinositol to the exterior. Upon insulin addition (10 nM), about 60% of the total glycosyl-phosphatidylinositol was hydrolysed in both hepatocytes and adipocytes but not in erythrocytes. In agreement with the extracellular localization in hepatocytes and with the proposed role of this glycolipid in insulin action, treatment of rat hepatocytes with beta-galactosidase from Escherichia coli, an enzyme that hydrolyses the oligosaccharide moiety of the glycosyl-phosphatidylinositol, cleaved 65% of the total glycophospholipid and blocked the effect of insulin (but not of glucagon) on pyruvate kinase (EC 2.7.1.40). Similar treatment with phosphatidylinositol-specific phospholipase C from Bacillus cereus hydrolysed 62% of the total glycosyl-phosphatidylinositol. From the various approaches used it is concluded that the majority of this glycophospholipid is at the outer surface in a variety of insulin-sensitive cells.
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PMID:Asymmetric distribution of the phosphatidylinositol-linked phospho-oligosaccharide that mimics insulin action in the plasma membrane. 213 37

This is a kinetic assay for measuring K+ in serum, based on the activation of pyruvate kinase (EC 2.7.1.40) by K+. We eliminated interference from Na+ and NH4+ ions, which also activate this enzyme, by including Na+-binding and NH4+-consuming reagents in the reaction mixture. The assay was developed with and evaluated in the Cobas Fara centrifugal analyzer (and has been used in other kinetic analyzers). Within-run and between-run CVs were less than 1.4% and less than 1.6%, respectively. The reaction rate per millimole of K+ per liter (0.05 delta A/min) was more than double that of the reagent blank (0.02 delta A/min). Results correlated well with those by flame photometry, and interference from bilirubin, hemoglobin, lipids, heparin, and other cations was negligible. This method, in conjunction with a previous method we have reported in which beta-galactosidase is used for measuring Na+ in serum, offers a practical alternative to the use of ion-selective electrodes and flame photometry for measuring these clinically important monovalent cations in high-throughput or "stat" biochemical analyzers.
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PMID:Enzymatic determination of potassium in serum. 272 Sep 76

Radiation inactivation is a method to determine the apparent target size of molecules. In this report we examined whether radiation inactivation of various enzymes and brain receptors is influenced by the preparation of samples preceding irradiation. The apparent target sizes of endogenous acetylcholinesterase and pyruvate kinase from rat brain and from rabbit muscle and benzodiazepine receptor from rat brain were investigated in some detail. In addition the target sizes of alcohol dehydrogenase (from yeast and horse liver), beta-galactosidase (from Escherichia coli), lactate dehydrogenase (endogenous from rat brain), and 5-HT2 receptors, acetylcholine muscarine receptors, and [35S] butyl bicyclophosphorothionate tertiary binding sites from rat brain were determined. The results show that apparent target sizes are highly influenced by the procedure applied for sample preparation before irradiation. The data indicate that irradiation of frozen whole tissue as opposed to lyophilized tissue or frozen tissue homogenates will estimate the smallest and most relevant functional target size of a receptor or an enzyme.
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PMID:The apparent target size of rat brain benzodiazepine receptor, acetylcholinesterase, and pyruvate kinase is highly influenced by experimental conditions. 284 37

A short sequence of predominantly basic amino acids Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val from SV40 Large T is responsible for the normal nuclear location of the protein. Alteration of Lys-128 to each of six different residues other than Arg renders Large T cytoplasmic, whereas single amino acid changes in the surrounding region impair but do not prevent nuclear accumulation. When transposed to the amino terminus of cytoplasmic Large T species, or Escherichia coli beta-galactosidase or of chicken muscle pyruvate kinase, the sequence around Lys-128 of Large T is able to direct the recipient protein to the nucleus. This demonstrates that these amino acids can be sufficient for nuclear location and can act as a nuclear location signal. A computer search of over 2500 proteins reveals that some other nuclear proteins (for example, BK virus Large T, SV40 VP2 and adenovirus 72kDa DNA binding protein) contain very similar basic tracts, but so too do some presumed non-nuclear proteins (for example, poliovirus VP3). We suggest that the related sequence acts as the nuclear location signal in the other nuclear proteins but that the sequence does not function in all cases, perhaps because it is not accessible. A similar, but shorter or less basic sequence, was detected in a number of other nuclear proteins, for example, polyoma virus Large T, SV40 VP1 and several histones. However, such sequences were also found in many other proteins. Perhaps the shorter basic sequences can also act as nuclear location signals, but to be functional they need to be exposed (for example, at the amino terminus of the protein as in SV40 VP1) or to be present in multiple copies.
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PMID:The nuclear location signal. 286 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 target size of four soluble enzymes (beta-galactosidase, pyruvate kinase, alcohol dehydrogenase, and glucose-6-phosphate dehydrogenase) in the presence or absence of subcellular membrane fractions has been determined by the radiation-inactivation method using samples in the frozen state. For each of the four enzymes, full activity was recovered after freezing and thawing in the absence of radiation. We found minimal (less than 20%) binding of the enzymes to either submitochondrial vesicles or sarcoplasmic reticulum vesicles. Under the conditions tested, beta-galactosidase, pyruvate kinase, and alcohol dehydrogenase exhibited target sizes which varied according to the experimental conditions, i.e., the buffer selected and also the presence or absence of membrane preparations. For these tetrameric enzymes, the target sizes were generally comparable to either a monomer or a dimer. By contrast, the target size of glucose-6-phosphate dehydrogenase from Leuconostoc mesenteroides was found to be essentially invariant when frozen in a variety of buffers and in the presence or absence of either cryoprotectant (sucrose or glycerol) or different membrane preparations. The target size from 19 separate determinations gave an average value of 104 +/- 16 kDa, which is comparable to the molecular weight of the enzyme (104 kDa). We conclude that glucose-6-phosphate dehydrogenase from L. mesenteroides is a reliable internal standard for radiation-inactivation studies of membrane preparations in the frozen state.
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PMID:Glucose-6-phosphate dehydrogenase from Leuconostoc mesenteroides is a reliable internal standard for radiation-inactivation studies of membranes in the frozen state. 392 13

A short sequence of amino acids including Lys-128 is required for the normal nuclear accumulation of wild-type and deleted forms of SV40 large T antigen. A cytoplasmic large T mutant that lacks sequences from around Lys-128 localizes to the nucleus if the missing sequence is attached to its amino terminus. The implication that the sequence element around Lys-128 acts as an autonomous signal capable of specifying nuclear location was tested directly by transferring it to the amino termini of beta-galactosidase and of pyruvate kinase, normally a cytoplasmic protein. Sequences that included the putative signal induced each of the fusion proteins to accumulate completely in the nucleus but had no discernible effect when Lys-128 was replaced by Thr. By reducing the size of the transposed sequence we conclude that Pro-Lys-Lys-Lys-Arg-Lys-Val can act as a nuclear location signal. The sequence may represent a prototype of similar sequences in other nuclear proteins.
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PMID:A short amino acid sequence able to specify nuclear location. 609 7

The present investigations on rat lung show that metabolic changes occurring around the 20th gestational day are accompanied by multiple alterations in the quantitative pattern of enzymes. This involves increases in two lysosomal enzymes (N-acetyl beta-glucosaminidase and beta-galactosidase) and a rise and fall in pyruvate kinase and alpha-glucosidase. The striking transient upsurge of adenylate kinase, however, is postponed until after birth. The normal diminution of thymidine kinase and peptidylproline hydroxylase is drastically enhanced by an injection of cortisol to fetal rats. Studies on human pulmonary tissues consisted in determining enzyme concentration from the ninth to the 21st week of gestation and an histologically normal adult lungs. The results show that the 15th to the 21st week of gestation is the period of increase in pyruvate kinase, adenylate kinase and alpha-glucosidase. The rise during the development of several enzymes (e.g., 5'-nucleotidase, alkaline phosphatase, and gamma-glutamyl transpeptidase) and the decline in thymidine kinase and peptidylproline hydroxylase, however, dose not begin until after the 21st week of gestation.
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PMID:Phosphotransferases and lysosomal enzymes in fetal human and rat lung. 626 41


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