Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adsorptive endocytosis of alpha-N-acetylglucosaminidase from human urine by isolated rat hepatocytes is inhibited by glycoproteins, polysaccharides and sugars that are known to bind to cell-surface receptors specific for either terminal galactose/N-acetylgalactosamine residues, terminal mannose residues or mannose 6-phosphate residues. Recognition of alpha-N-acetylglucosaminidase by a cell-surface receptor specific for terminal galactose/N-acetylgalactosamine residues is supported by the observations (a) that neuraminidase pretreatment of the enzyme enhances endocytosis, (b) that beta-galactosidase treatment decreases endocytosis and (c) that neuraminidase pretreatment of hepatocytes decreases alpha-N-acetylglucosaminidase endocytosis. Recognition of alpha-N-acetylglucosaminidase via receptors recognizing mannose 6-phosphate residues is lost after treatment of the enzyme with alkaline phosphatase and endoglucosaminidase H. The effect of endoglucosaminidase H supports the view that the mannose 6-phosphate residues reside in N-glycosidically linked oligosaccharide side chains of the high-mannose type. The weak inhibition of endocytosis produced by compounds known to interact with cell-surface receptors specific for mannose residues suggests that this recognition system plays only a minor role in the endocytosis of lysosomal alpha-N-acetylglucosaminidase by hepatocytes.
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PMID:Recognition of human urine alpha-N-acetylglucosaminidase by rat hepatocytes. Involvement of receptors specific for galactose, mannose 6-phosphate and mannose. 11 70

Human adult lung fragments removed from macroscopically undamaged and anthracosis exempted zones of lungs of 20 pneumonectomies made for cancer, were tested for 25 enzymic activities. The location and intensities of these enzymic activities were different in the lung tissue components; The bronchial epithelia contained highly active LDH, MDH, SDH, NADH-TR and NADPH-TR, glucose-6-phosphate dehydrogenase, active hydroxyproline-2-epimerase, alkaline phosphatase. Ca2+-activated ATP-ase, and beta-galactosidase. Bronchial and vascular muscles presented intense activities of LDH, MDH and SDH of alkalinephosphatase, AMP-ase and Ca2+-activated ATP-ase, as well as of beta-galactosidase. The alveolar walls presented high activities of SDH, MDH and LDH, of alkaline and acid phosphatases, of beta-galactosidase and of Tween-40 and 60-esterases, of HEP, cytochrome-oxidase and peroxidase. The free alveolar macrophages were active for LDH, MDH, SDH, NADH-TR and NADPH-TR, G1-6-ph-DH, acid and alkaline phosphatase, cytochrome-oxidase and peroxidase, HEP, AMP-ase and Mg2+-activated ATP-ase, Tween-esterases, naphthol-ASD-acetate esterase, and beta-galactosidase. The endothelia contained high activities of alkaline phosphatase, of AMP-ase and Mg2+-activated ATPase, of LDH, MDH and SDH, and of beta-galactosidase. In bronchial lymphoid nodules it was the LDH, MDH, SDH, cytochrome-oxidase and peroxidase, HEP, alkaline phosphatase and AMP-ase, Tween-60-esterase and beta-galactosidase that were active. The interlobular areas of the lung presented intense activities of SDH, MDH, LDH, HEP and cytochrome-oxidase. The activities of the other tested enzymes were weaker or absent in the adult human lung components, the same as those of aminopeptidases which were present only in some free alveolar macrophages. The discussion of some relationships between these enzymic actitivies and the morphology of the human adult lung tissue asserted that the latter could not be considered as a "normal" tissue but as one overstrained by the components of blood and polluted air.
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PMID:Histoenzymology of the lung. I. Enzyme activities of the lung tissue of acult humans; relationships between structure and functions. 14 Mar 14

The study deals with the distribution of acid and alkaline phosphatases, ATPase, 5-nucleotidase, nonspecific esterase, specific cholinesterase, and beta-galactosidase in the diencephalon of the frog. The highlights of the present study are the following: i) Acid phosphatase is present in all the neurons, whereas the tracts and commissures are completely negative. ii) Most of the tracts and commissures are positive for 5-nucleotidase. This confirms the author's previous findings that the tracts and commissures of all the areas of frog brain are intensely positive for 5-nucleotidase. iii) beta-galactosidase activity in the nuclei of the diencephalon is either mild or completely absent, whereas the commissures and tracts show positive activity. iv) Habenulothalamic connections are intensely positive for specific cholinesterase and non-specific esterase, moderately positive for beta-galactosidase and completely negative for other enzymes. v) The epiphysis (pineal organ) shows intense reaction for adenosine triphosphatase, acid phosphatase, and 5-nucleotidase and moderate reaction for alkaline phosphatase and non-specific esterase. In contrast to the above enzymes, the specific cholinesterase and beta-galactosidase are completely missing. vi) Lateral forebrain bundles are completely negative for all the enzymes except alkaline phosphatase and beta-galactosidase. The distribution of these enzymes has been correlated with the functional aspects of various nuclei, tracts, and commissures of the diencephalon of the frog.
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PMID:The chemoarchitectonics of the diencephalon of frog (Rana tigrina). 15 81

Histological studies showed that the administration of p-nitrophenylarsonic acid to rats resulted in renal tubular necrosis. The nephrotoxin was administered intraperitoneally and doses greater than 30 mg/kg were found to be fatal. The severity of the renal lesion depended on the amount of the nephrotoxin used. Elevated serum urea levels, urinary protein and volume were recorded over an 8-day period following the injection of the nephrotoxin. These changes were paralleled by an increase in the activity of lactate dehydrogenase, acid and alkaline phosphatase, N-acetyl-beta-glucosaminidase and beta-glucosidase in the urine. beta-Glycosidase activities increased in kidney homogenates, immediately after the injection of the nephrotoxin, but this eventually fell to well below the normal range. Subcellular fractions were prepared from sucrose homogenates by differential centrifugation and beta-glycosidases and cytochrome oxidase were used as enzyme markers. Only minor changes in the activity of cytochrome oxidase activity resulted from the administration of p-nitrophenylarsonic acid. One of the earliest indications of renal damage was a decrease in lysosomal latency. The activities of the lysosomal and soluble enzymes were elevated above normal during the first two days after the injection of p-nitrophenylarsonic acid, but they fell to values, significantly lower than normal, on the third day. The isoenzymic forms of beta-galactosidase, beta-glucosidase and N-acetyl-beta-glucosaminidase in normal and damaged kidneys were studied, using starch gel electrophoresis. The activities of both the lysosomal and the soluble forms of these enzymes decreased following the injection of the nephrotoxin, confirming the results obtained with whole homogenates. The relationship between the changes in renal enzyme activity and urinary enzyme excretion during the nephrotoxic process is discussed.
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PMID:Studies on the nephrotoxicity of p-nitrophenylarsonic acid: changes in rat kidney and urinary enzyme activities following the administration of p-nitrophenylarsonic acid. 21 43

The mechanisms for transport and hydrolysis of lactose were investigated in five cariogenic strains (HS6, AHT, FA1, NCTC 10449, and SL1) representing the four serogenetic groups of Streptococcus mutans. The systems for transport and hydrolysis of lactose had the characteristics of a phosphoenolpyruvate (PEP)-dependent lactose (Lac) phosphotransferase (PT) system and phospho-beta-galactosidase (P-beta-gal), respectively, in all strains tested, except strain HS6. Decryptified cells required PEP and Mg(2+) for transport of the non-metabolizable model beta-galactosides o-nitrophenyl-beta-d-galactopyranoside (ONPG) and thiomethyl-beta-d-galactopyranoside (TMG). Substitution of 2-phosphoglycerate (2-PG) for PEP also stimulated the Lac PT system. Other potential high-energy phosphate donors (adenosine tri-, di-, and monophosphates and guanosine triphosphate) did not stimulate the Lac PT system. Sodium fluoride had no effect upon the PEP-dependent Lac PT system in decryptified cells with PEP as the energy source; however, when 2-PG was used as the energy source, F(-) inhibited ONPG phosphorylation. With intact cells which must generate PEP endogenously, the presence of F(-) in concentration >/= 10 mM completely inhibited the Lac PT system, presumably through inhibition of 2-PG hydrolyase (EC 4.2.1.11; enolase). Both intact and decryptified cells accumulated a phosphorylated derivative of TMG that behaved chromatographically as TMG-phosphate. After alkaline phosphatase treatment, the derivative had an R(f) identical to that of TMG. No beta-galactosidase (beta-gal) activity was detected with ONPG as the substrate; hydrolysis occurred only when ONPG-6-phosphate was supplied as the substrate. Strain HS6 apparently transported lactose by an active transport-type system in which the accumulated intracellular product was the free disaccharide based on the following criteria: (i) ONPG transport and hydrolysis in decryptified cells was not stimulated by PEP; (ii) ONPG hydrolysis occurred in the absence of PEP; and (iii) ONPG-6-phosphate was not hydrolyzed. These data indicate that, in all strains tested except strain HS6, lactose transport was mediated by a PEP-dependent Lac PT system, resulting in accumulation of lactose-phosphate that was hydrolyzed by an enzyme similar to the P-beta-gal of group N streptococci and Staphylococcus aureus; conversely, strain HS6 transported and hydrolyzed lactose by a PEP-independent transport system and beta-gal, respectively.
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PMID:Involvement of phosphoenolpyruvate in the catabolism of caries-conducive disaccharides by Streptococcus mutans: lactose transport. 24 29

The subcellular localization of aminopeptidase N (previously called aminoendopeptidase) has been investigated. This enzyme was found to be partially released (30-40%) by osmotic shock or by converting Escherichia coli K10 cells to spheroplasts. However, in all other E. coli strains (K12, B/r, MRE 600, ML 308) tested, this enzyme is not released at all by these procedures and thus behaves like a cytoplasmic enzyme. The crypticity of aminopeptidase N is surprisingly low, 75-85% of the enzyme activity is directly assayable in intact cells of any E. coli strain. Various inhibitors of transport systems do not interfer with this assay. Aminopeptidase activity could also be assayed in spheroplasts, even when an insolubilized substrate was used, which suggests a surface location of this enzyme. As well, N-ethylmaleimide (0.4 mM), under conditions which do not allow penetration in the cytoplasm, caused 70% inhibition of aminopeptidase N. Binding of 125I-labeled antiaminopeptidase N antibody to spheroplasts (from K12 strain) was used to assay the orientation of aminopeptidase N in the membrane. This enzyme is exposed on the outer surface of the cytoplasmic membrane. Confirmation of this orientation was obtained by comparing the accessibility of aminopeptidase, alkaline phosphatase and beta-galactosidase to fluorescamine in intact cells. Only 16% of the total beta-galactosidase was labeled with this fluorescent reagent whereas 44-45% of the aminopeptidase N and 59% of the alkaline phosphatase were labeled. Electron microscopic visualization of insolubilized reaction products of aminopeptidase N within the cells showed that these products are located at the poles of the cells. Neither mutant cells which were devoid of aminopeptidase N activity nor parental strains with the enzyme activity inhibited with phenylmercuric chloride contained the characteristic black caps. Thus, it appears that the periplasm is enlarged at the poles of the cells and that the reaction product is mainly located in these places. Investigation of the type of interactions of aminopeptidase N with the plasma membrane only revealed that aminopeptidase N has mainly an electrostatic interaction with the outer surface, probably mediated by magnesium ion bridges. Additional interactions are involved since disruption of the integrity of the cytoplasmic membrane is required to totally release this enzyme.
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PMID:Aminopeptidase N from Escherichia coli. Unusual interactions with the cell surface. 32 10

Ferritin-conjugated specific antibodies have been used to localize beta-galactosidase and both the monomer and active dimer of alkaline phosphatase in frozen thin sections of cells of Escherichia coli O8 strain F515. The even distribution of the ferritin marker throughout cells that had been induced for beta-galactosidase synthesis, frozen, sectioned, and exposed to ferritin-anti-beta-galactosidase conjugate showed that this enzyme was present throughout the cytoplasm of these cells. Frozen thin sections of cells that had been derepressed for the synthesis of alkaline phosphatase were exposed to both ferritin-anti-alkaline phosphatase monomer and ferritin-anti-alkaline phosphatase dimer conjugates, and the ferritin markers showed a peripheral distribution of both the monomer and the dimer of this enzyme. This indicates that alkaline phosphatase is present only in the peripheral regions of the cell and argues against the existence of a cytoplasmic pool of inactive monomers of this enzyme. This peripheral location of both the monomers and dimers of alkaline phosphatase supports the developing concensus that this enzyme is, like other wall-associated enzymes, synthesized in association with the cytoplasmic membrane and vectorially transported to the periplasmic area, where it assumes its tertiary and quaternary structure and acquires its enzymatic activity.
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PMID:Immunocytological investigation of protein synthesis in Escherichia coli. 32 33

The effect of procaine hydrochloride, an anesthetic known to alter membrane structure, on the induced formation of alkaline phosphatase, a periplasmic enzyme, in Escherichia coli was investigated. Procaine hydrochloride specifically arrested the appearance of active alkaline phosphatase while permitting the induction of another enzyme, beta-galactosidase, which is internally localized. Evidence has been obtained to show that procaine hydrochloride does not arrest synthesis of inactive monomer subunits of the enzyme, indicating that the drug interferes in the conversion of monomer subunits to an active dimer enzyme.
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PMID:Induction of alkaline phosphatase in Escherichia coli: effect of procaine hydrochloride. 32 82

Using fresh frozen, freeze-dried or cryostate sections from aldehyde fixed rat tissues 13 diazonium salts were tested as simultaneous coupling reagents for the localization of acid, neutral and alkaline hydrolases with azo indoxyl methods. Hexazotized new fuchsine and/or Fast blue B are the diazonium salts of choice for the demonstration of acid beta-galactosidase, neuraminidase, beta-N-acetylglucosaminidase, acid phosphatase, and non-specific esterase followed by hexazotized p-rosaniline. Fast blue VB, BB and RR and Fast violet B are recommended for the investigation of alkaline phosphatase and lactase, Fast garnet GBC for acid beta-galactosidase, glucosaminidase and lactase. Fast red B, RC, RL and TR and Fast black K can only be employed for lactase studies. The exact concentration of the coupling reagent depends on the activity of the enzyme and the organ imvestigated. On the average 0.01-0.02 ml unstable diazonium salt/ml and 0.3--1 microgram stable diazonium salt/ml are sufficient for the correct localization of these hydrolases. Freeze-dried cryostat sections yield the best results in the demonstration of lactase and alkaline phosphatase independent on the coupling reagent used. Sections from formaldehyde or glutaraldehyde fixed organs are superior for the localization of the other hydrolases; an exception is the investigation of acid beta-galactosidase and glucosaminidase with Fast garnet GBC. Then, excellent results are obtained also with freeze-dried material. Fresh frozen sections are suitable for the localization of lactase with hexazotized new fuchsine or p-rosaniline and of alkaline phosphatase with Fast blue VB and BB or violet B. The total activity of acid, neutral and alkaline hydrolases can be investigated using semipermeable membranes in combination with all unstable and stable diazonium salts of choice. Reliable osmification of the azoindoxyl dye is only possible if hexazotized p-rosaniline is employed for coupling; without further posttreatment all azoindoxyl dyes are extracted by ethanol, isopropanol or xylol. 7 incubation media are given for the demonstration of hydrolases with azoindoxyl methods at the level of light microscopy for routine studies and typical examples for the application of these methods are presented. A modified procedure is described for the freeze-drying of cryostat sections with the Edwards-Pearse tissue dryer EPD3.
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PMID:[Azoindoxyl methods for the investigation of hydrolases. IV. Suitability of various diazonium salts (author's transl)]. 36 63

The induction of beta-galactosidase and alkaline phosphatase by the nucleoid of Escherichia coli was studied. Only the membrane-associated form was active in the presence of S 30. The induction of beta-galactosidase showed an absolute requirement for the inducer and was enhanced by cyclic AMP and cyclic GMP. Further-more, in our hands, the synthetic activity of the membrane-associated nucleoid proved to be far higher than that of the soluble system described by Zubay. Our results suggest that membrane shield the structure which is necessary for the integrity of the initiation step of both transcription and translation.
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PMID:[Synthesis of specific proteins by the nucleoid of Escherichia coli]. 40 27


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