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)

Endo-beta-galactosidase, a glycosidase that hydrolyzes Gal beta 1-4 GlcNAc linkages in glycoconjugates, has been used to probe the plasma membrane of human erythrocytes. Coomassie blue staining of stroma components separated by sodium dodecyl sulfate-acrylamide gel electrophoresis indicates that treatment of red cells with endo-beta-galactosidase converts Protein 3, the anion transporter of the erythrocyte, to a more compact staining band. No other components detected by Coomassie staining are affected. Following labeling of red cells with galactose oxidase + NaB3H4, 45 to 50% of the [3H]galactose residues can be released by endo-beta-galactosidase. In contrast, only 5% of the label incorporated by treatment with periodate + NaB3H4, can be removed. [3H]Galactose residues are released from three components: Protein 3, Band 4.5, and the megaloglycolipids. The susceptibility of these components to endo-beta-galactosidase, together with the high content of Gal and GlcNAc present in Protein 3 and the megaloglycolipids, suggests that the erythrocyte membrane contains several components with N-acetyllactosamine repeating units, a structure commonly found in connective tissue glycoconjugates.
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PMID:Effect of endo-beta-galactosidase on intact human erythrocytes. 11 98

Human lymphocyte cultures produced large amounts of interferon after treatment with the enzyme galactose oxidase. Interferon production was detectable as early as 3 h after enzymatic treatment and reached a level of about 10(4) reference units 20 to 24 h later. Galactose oxidase-induced interferon appeared to be immune interferon on the basis of acid lability, lack of neutralization by antibody to leukocyte interferon, and slow kinetics of activation of the cellular antiviral state. Interferon production was inhibited to the same extent (99%) by pretreatment of the cells with beta-galactosidase or with neuraminidase followed by beta-galactosidase, suggesting that the critical event for activation of interferon production is the oxidation of exposed galactose residues on lymphocyte membrane.
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PMID:Enzymatic induction of interferon production by galactose oxidase treatment of human lymphoid cells. 11 35

Several classes of proteolytic enzymes were used to gain an insight into the biochemical composition of the antiotensin II (ATII) receptor prepared from bovine adrenal cortices. Exposure of the receptor fractions to trypsin reduced their capacity to bind [3H]ATII. Phospholipases A2 and C similarly inhibited the [3H]ATII binding process, while phospholipase D had no effect. Binding was stimulated following addition of phosphatidylcholine but inhibited by lysophosphatidylcholine. Neuraminidase had no influence on [3H]ATII affinity for binding, while beta-galactosidase reduced binding of the radioligand. Concanavalin A did not displace [3H]ATII bound to receptor fractions. Very little aminopeptidase activity was detected in the receptor fraction, relative to the homogenate. The data suggest that the ATII recognition sites contain protein moieties, while phospholipids may play an essential role in ATII binding. Galactose units may form a part of the ATII receptor not directly associated with the binding site. The peptidase studies indicate that ATII probably cannot be hydrolyzed to its des-Asp1 metabolite at or near the site of binding.
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PMID:Enzymatic modifications of bovine adrenocortical angiotensin II receptors. 22 26

Peanut agglutinin, purified by affinity chromatography, agglutinates lymphocytes from mouse, rat, guinea pig, and man only after their treatment with neuraminidase. However, it stimulates only neuraminidase-treated rat and human cells. A similar number cell surface receptors for peanut agglutinin was found on neuraminidase-treated rat and mouse lymphocytes although the latter cells were not stimulated by the lectin. Galactose specifically inhibited the agglutination and stimulation of lymphocytes by peanut agglutinin. Sequential treatment of lymphocytes with neuraminidase and beta-galactosidase markedly reduced the response of the cells to stimulation by peanut agglutinin, soybean agglutinin, and galactose oxidase. It is suggested that the same galactosyl residue may be the target for the initial step in triggering lymphocytes by the above mentioned mitogens.
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PMID:Peanut agglutinin, a new mitogen that binds to galactosyl sites exposed after neuraminidase treatment. 117 75

Clinical findings and lysosomal enzymes (LYE) in eight lumpy skin diseases (LSD) cows and same number of healthy ones were reported in Tal-El Baker village and Tal Alkabir centre, Ismailia province, Egypt. LSD began with fever, anorexia, skin lesions in form of nodules all over the body, which disappeared spontaneously or gathered to form large lumps. It was complicated with respiratory manifestation, corneal opacity, mastitis, dehydration and later on recumbency. It is noteworthy that the level of 3 LYE showed the same trend of significant reduction in acute stage of the disease (5 days after occurrence of LSD) probably due to injection of animals with a therapeutics dose of terramycin. Acid-phosphatase (ACP) enzyme is the sole that behaved very high significant increase in the serum in acute stage of LSD due to the damaged tissues caused by the virus. It underwent insignificant decrease in late stage of the disease (20 days after its occurrence) to restore the normal LYE level in control cows indicating recovery. Alpha-galactosidase (alpha-GAL) decreased perpetually by the progression of LSD because of the decreased bactericidal index which ist in concomitance with the secondary bacterial invader. N-acetyl-beta-glucosaminidase (beta-NAG) and beta-galactosidase (beta-GAL) in LYE had the same fluctuating manner. The activities showed very highly significant decrease in acute stage, followed by highly significant and significant increases (late LSD stage) respectively. The appreciable significant increase of beta-GAL may declare the effect of anorexia on LSD. In view of these findings, it can be postulated that LSD may be diagnosed and prognosed through LYE changes in the serum.
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PMID:Characterization of serum lysosomal enzymatic activities. II. Effect of lumpy skin disease in Egyptian cows. 133 Apr 81

Urinary dilution adjustment methods can be used to reduce the intra-individual variability in concentrations of metals and other substances in urine due to variability in urinary flow. In this study linear and non-linear dilution adjustments with urinary flow, creatinine (CREAT) and urinary density (UD) were compared for the urinary enzymes alanine amino peptidase (AAP), beta-galactosidase (beta GAL) and N-acetyl-beta, D-glucosaminidase (NAG). The most optimal dilution adjustment for AAP was: AAPadjusted = AAPmeasured/(CREATmeasured)0.824 The optimal dilution adjustment for beta GAL was: beta GALadjusted = beta GALmeasured/(CREATmeasured)0.878 For NAG the optimal dilution adjustment parameter was the conventional linear adjustment with SG. It could not be determined whether urinary dilution methods can be useful for population based reference intervals of urinary enzymes. If personal reference intervals can be calculated, urinary dilution adjustment methods may be useful by reduction of intraindividual variability.
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PMID:A comparison of dilution adjustment methods for urinary enzymes. 135 36

In a previous paper we have studied the expression of beta-galactosidase from Escherichia coli, driven from the inducible GAL1-10/CYC1 hybrid promoter, in batch cultures of budding Saccharomyces cerevisiae and have described operating conditions for maximal productivity. In this paper we show that the plasmid instability in continuous cultures can be overcome by utilizing appropriate selection markers and a high copy number vector. The maximal level of expression is influenced by the dilution rate. Moreover, enzyme accumulation appears to depend also upon the degree of oxygenation. A possible explanation of these modulations is discussed, taking into account the interactions of the UAS-GAL and TATA-CYC1 elements.
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PMID:Heterologous gene expression in continuous cultures of budding yeast. 136 26

We have shown that the Leishmania major transfection vector pR-NEO (or derivatives thereof) can be introduced and stably maintained in four species complexes of pathogenic Leishmania (L. tropica, L. mexicana, L. donovani, L. braziliensis), and the genera Endotrypanum and Crithidia; transfection of Trypanosoma cruzi or Trypanosoma brucei was not successful. Quantitative plating assays showed that the transfection efficiencies were high in L. major and Leishmania amazonensis (5x10(-5)/cell) and about 10-fold less for Leishmania panamaensis and Crithidia. Leishmania donovani transfected with pR-NEO retained the ability to infect hamsters, and amastigotes recovered after 2 months yielded G418-resistant promastigotes which retained high levels of extrachromosomal pR-NEO DNA. In promastigotes, the transfected DNA existed as extrachromosomal circles, and expressed the predicted 2.4-kb hybrid NEO/DHFR-TS mRNA bearing the trans-spliced miniexon. Large quantitative differences were observed only in Crithidia: relative to transfected Leishmania species, the copy number of pR-NEO was elevated 20-fold, while the levels of the NEO/DHRFR-TS mRNA or Escherichia coli beta-galactosidase (synthesized from the expression vector pX-beta GAL) were reduced 80 and more than 1000-fold, respectively. Thus, genetic signals derived from L. major DNA that mediate RNA expression or stability are recognized by the heterologous Leishmania species but less efficiently by Crithidia. These studies suggest that pR-NEO derived vectors may be applied to the study of genes expressed throughout the life cycle in a wide range of pathogenic trypanosomatids.
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PMID:Stable DNA transfection of a wide range of trypanosomatids. 190 80

Rhodopsin's oligosaccharide chains contain predominantly two types of sugar residues: mannose and N-acetylglucosamine. In the present work, bovine and rat rhodopsin were analysed biochemically for the presence of a third sugar, galactose. Treatment of bovine rod outer segments (ROS) with galactose oxidase followed by reduction with tritium-labeled sodium borohydride revealed the presence of existing molecules of galactose on rhodopsin. Rats injected intravitreally with [3H]galactose and [14C]leucine and maintained in darkness were killed 1 hr, 6 hr, 1, 3 or 5 days following the injection. Retinas were collected for subcellular fractionation and rhodopsin from each of the fractions was purified by ConA sepharose chromatography and SDS-PAGE. During the first 6 hr, galactose selectively labeled rhodopsin in the Golgi-enriched fraction resulting in increased [3H]/[14C] ratios in both Golgi and ROS. The data suggested that trimming was occurring at the transition from Golgi to ROS. Furthermore, a decrease in isotope ratio in the ROS between 6 hr and 1 day suggested further trimming of rhodopsin after membrane assembly in the ROS. Additional in vivo experiments demonstrated existing molecules of galactose on rhodopsin's oligosaccharide chain using lectin affinity chromatography. Rats injected intravitreally with [35S]methionine were dark-adapted for 2 hr. Following subcellular fractionation of retinas, ConA purified rhodopsin from ROS was applied to one of two additional lectin columns: Ricinus communis agglutinin (RCA) or Griffonia simplicifolia I (GSA). Eight to nine percent of the labeled rhodopsin was bound to and eluted from RCA, whereas none bound to GSA, indicating the presence of a beta-galactoside. The RCA agarose eluted protein co-electrophoresed with a rhodopsin standard and was light sensitive. Galactose was shown to be the terminal sugar on this subset of rhodopsin and was not capped by neuraminic acid. Binding of rhodopsin's oligosaccharide to RCA was abolished by pre-treatment with beta-galactosidase. Decreased binding of rhodopsin to RCA was observed following intravitreal injection of castanospermine but not swainsonine. Of those two inhibitors of glycoprotein trimming, only castanospermine would be expected to prevent the addition of galactose to the oligosaccharide. The association of galactose with rat rhodopsin appeared to be a transient one. At 2 hr, 8-9% of rhodopsin contained galactose, at 6 hr only 2.2% had galactose and by 24 hr less than 1% did. The galactose was trimmed from rhodopsin's oligosaccharide presumably after its role was complete. Separation of rhodopsin of the plasma membranes from rhodopsin of discs indicated that 75% of the galactose-containing rhodopsin was in the plasma membrane and only 25% was in the discs. These findings suggested a possible role for galactose in new disc formation with subsequent removal after the discs are sealed.
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PMID:Transient hyperglycosylation of rhodopsin with galactose. 193 88

The structure of the N-linked oligosaccharide of the 85-kDa surface glycoprotein (Tc-85) from the infective trypomastigote form of Trypanosoma cruzi was investigated. Tc-85 metabolically labeled with [14C]glucose was purified by affinity chromatography on wheat germ agglutinin-Sepharose. Binding to the lectin was lost on treatment of Tc-85 with neuraminidase. The N-linked asialo-oligosaccharide was released by endo-beta-N-acetylglucosaminidase F digestion of asialo-Tc-85 and was further analyzed using specific exoglycosidases. [14C]fucose was detected after alpha-L-fucosidase treatment or mild acid hydrolysis. The afucosyl oligosaccharide was 3H-labeled by the galactose oxidase-NaB3H4 method. [3H]Galactose was released by alpha-galactosidase, and only then was beta-galactosidase effective in removing another galactose. The gal(alpha 1-3)gal unit was demonstrated by periodate oxidation studies on the [3H]galactose-labeled asialo-glycoprotein. The presence of gal(alpha 1-3)gal in Tc-85 could be related to the recent finding of elevated antibody levels against this epitope in patients with Chagas' disease.
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PMID:The N-linked carbohydrate chain of the 85-kilodalton glycoprotein from Trypanosoma cruzi trypomastigotes contains sialyl, fucosyl and galactosyl (alpha 1-3)galactose units. 210 74


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