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)

Flavonoids (103 species) were tested for inhibitory activity against influenza virus sialidase using sodium p-nitrophenyl-N-acetyl-alpha-D-neuraminate as substrate. 5,7,4'-Trihydroxy-8-methoxyflavone from the root of Scutellaria baicalensis showed the most potent activity (IC50, 55 microM), and this flavone appeared to be a non-competitive inhibitor of the enzyme. Whereas, negligible or weak inhibitory activities were observed for mouse liver sialidase, beta-galactosidase and alpha-mannosidase as tested. This flavone also inhibited the infection by influenza virus A/PR/8/34 of Madin-Darby canine kidney cells, and replication of the virus in the allantoic sack of embryonated egg. These results suggest that flavone, which has potent influenza virus sialidase inhibitory activity, may have anti-influenza virus activity.
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PMID:Inhibition of influenza virus sialidase and anti-influenza virus activity by plant flavonoids. 239 58

Two monoclonal antibodies, NCC-LU-35 and NCC-LU-81, have been established after immunization of mice with membrane preparations of human lung cancer Lu65 tumor xenograft cells grown in vivo and intact cells cultured in vitro, respectively. These two antibodies react specifically with a majority of human adenocarcinomas, irrespective of the host's blood group ABO status, as well as with normal tissues and erythrocytes of blood group A individuals. The antigenicity is associated with a high molecular weight mucin-like glycoprotein separated by gel filtration of Lu65 tumor extracts. The epitope of the mucin-like glycoprotein has been identified as alpha-N-acetylgalactosaminyl residue directly linked O-glycosidically to serine or threonine residues of polypeptides. This epitope was serologically detected several years ago and given the name Tn. Our identification of the epitope is based on the following results: The antigen is sensitive to alpha-N-acetylgalactosaminidase, but not to sialidase or alpha-fucosidase. Various mono- and difucosyl A determinants, either type 1 or type 2 chain, cross-react with both antibodies. The reactivity with both antibodies can be created by treatment of glycophorin A of normal erythrocytes with sialidase followed by beta-galactosidase. N-[3H]acetylgalactosamine can be released by galactose oxidase/NaB3H4 treatment from the Lu65 mucin-like glycoprotein but not from the mucin-like glycoprotein of normal colonic mucosa upon reductive beta-elimination (alkaline borohydride treatment). The antigen may be one of the tumor-associated A cross-reacting antigens occurring in a wide variety of human adenocarcinomas of hosts belonging to all ABO blood groups.
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PMID:Blood group A cross-reacting epitope defined by monoclonal antibodies NCC-LU-35 and -81 expressed in cancer of blood group O or B individuals: its identification as Tn antigen. 241 56

Sensitive staining methods with wheat germ agglutinin were developed for the detection of glycosphingolipids of neolacto series (A) and gangliosides with a terminal N-acetylneuraminyl residue (B) on thin-layer chromatograms. (A) Neolacto series glycosphingolipids were treated by beta-galactosidase on the chromatograms in the presence of taurodeoxycholate. Then the chromatograms were incubated with biotinated wheat germ agglutinin followed by incubation with a complex of avidin and biotinated horseradish peroxidase, and the reaction was detected by 4-chloro-1-naphthol. In the case of gangliosides, sialidase treatment on the chromatograms was performed before the beta-galactosidase treatment. The sensitivity of the method for Lc3Cer, nLc4Cer, sialyl-nLc4Cer, and sialyl-nLc6Cer was 4 pmol, 7.6 pmol, 2.9 pmol and 1.4 pmol, respectively. (B) The gangliosides on the chromatograms were oxidized by periodic acid and reduced by NaBH4. Then the chromatograms were stained with wheat germ agglutinin as mentioned above. As little as 0.5 pmol of GM3, NeuAc-nLc4Cer, and NeuAc-nLc6Cer was detected by this method, whereas the detected limits for these gangliosides were 10 pmol, 10 pmol and 2 pmol, respectively, when periodate oxidation was omitted. GM4, GD3 and GD1a were an order less reactive than GM3, GM2, GM1 or GD1b were not stained under the same condition. In contrast to NeuAc-containing gangliosides, any gangliosides with N-glycolylneuraminic acid were not stained by the method in (B).
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PMID:Specific staining on thin-layer chromatograms of glycosphingolipids of neolacto series and gangliosides with a terminal N-acetylneuraminyl residue by different procedures with wheat germ agglutinin. 246 40

Using lectin staining methods in combination with exo- and endo-glycosidase digestion procedures, we analyzed the chemical structure of different types of blood group-related substances in serous cells of formalin-fixed, paraffin-embedded human submandibular glands. Serous cells produced only H antigen; A and B antigens were not present, and the expression of H antigen is dependent on the secretor status of the tissue donor. Although reactivity with Ulex europaeus agglutinin I (UEA-I) was not markedly reduced by alpha-L-fucosidase digestion, an affinity for peanut agglutinin (PNA) was seen after fucosidase digestion in the cells from secretors. In those from nonsecretors, no PNA reactivity appeared after enzyme digestion. On the other hand, sialidase digestion elicited PNA reactivity in serous cells irrespective of the donor's secretor status. PNA reactivity observed after fucosidase or sialidase digestion was susceptible to endo-alpha-N-acetylgalactosaminidase (endo-GalNAc-dase) digestion. SBA reactivity in UEA-I-negative cells from secretors, or in cells from fetuses and newborn infants, was markedly reduced by beta-galactosidase digestion. After galactosidase digestion, reactivity with Griffonia simplicifolia agglutinin II (GSA-II) appeared in the corresponding cells. This GSA-II reactivity was almost completely eliminated by subsequent beta-N-acetylhexosaminidase digestion. Whereas PNA reactivity in these cells was not reduced by beta-galactosidase treatment, it was significantly diminished by endo-GalNAc-dase digestion. These results suggest that at least two kinds of precursor disaccharides are produced in submandibular serous cells, i.e., SBA-reactive D-galactose-(beta 1-3,4)-N-acetyl-D-glucosamine and PNA-reactive D-galactose-(beta 1-3)-N-acetyl-D-galactosamine alpha 1-serine or threonine (O-glycosidically linked Type 3 chain or T antigen). Final fucosylation and synthesis of these two types of precursor chain appear to be under the control of the secretor gene.
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PMID:Histochemical analysis of the chemical structure of blood group-related carbohydrate chains in serous cells of human submandibular glands using lectin staining and glycosidase digestion. 249 20

We described a case of late-infantile form of galactosialidosis. This male patient was a product of normal pregnancy. His parents were first cousins. He first sat at eight months, walked and talked at two years of age. His gait gradually became unsteady and he was diagnosed as spastic paraparesis at the age of five years. Abnormally slow learning was first pointed out at seven years of age. At the age of nine years, we evaluated him in detail at our university hospital. Physical examination revealed a short stature for his age, slightly coarse face, short neck, funnel chest, genu, pes and hallucis valgus. Corneal clouding, hernia and angiokeratoma were not found. Neurological examination showed mental retardation, bilateral optic atrophy without cherry-red spots, and spastic and slightly ataxic gait. Slight muscular atrophy with weakness was also seen in the extremities, more remarkable in the lower limbs. Deep tendon reflexes were hyperactive with bilateral ankle clonus and no extensor planter response. Routine examination of blood, urine and cerebrospinal fluid were normal except for approximately 10% lymphocytes containing cytoplasmic vacuoles. X-ray films of the backbone exhibited vertebral plana with anterior breaking at the second lumbar vertebra level. The electroencephalography showed the multiple spike and slow wave complexes. Brain CT depicted the atrophy of cerebellum. The activities of sialidase and beta-galactosidase were markedly reduced in white blood cells and cultured skin fibroblasts in this patient. His urinary excretion of sialyloligosaccharides increased.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Late-infantile form galactosialidosis with psychomotor retardation and spastic paraparesis]. 251 61

Electrophysiological investigation was performed in 3 patients with beta-galactosidase and sialidase deficiencies (sialidosis type 2) in order to elucidate the underlying mechanism of intention myoclonus. It is a rare neuronal storage disease that begins in childhood with mental retardation, skeletal abnormalities, progressive myoclonus and cherry-red spots in the macula. Electrophysiological studies showed paroxysmal activities in the EEG, consistent temporal relationship between the EEG spikes and myoclonic jerks demonstrated by jerk-locked averaging, high amplitude somatosensory evoked potentials with altered wave form, and enhanced long-loop reflexes. These results suggest that there is a hyperexcitability of the cerebral cortex, which results in induction of intention myoclonus. The intention myoclonus in sialidosis type 2 is consistent with 'cortical reflex' myoclonus described in progressive myoclonic epilepsy due to various etiologies.
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PMID:Electrophysiological studies of myoclonus in sialidosis type 2. 257 48

Sites of binding of eight different lectins (LTA, UEA I, WGA, SBA, DBA, CON A, PNA, RCA I) to cat submandibular gland were studied after exposure of tissue sections to sialidase, alpha-fucosidase, beta-galactosidase, alpha-mannosidase, beta-N-acetylglucosaminidase. All lectins were affected by enzymatic predigestion and the labeling of individual lectins was highly dependent upon the glycosidase used to pretreat the sections. Glycoconjugates of demilunar, acinar and ductal cells exhibited a different composition of terminal sequences. For example, fucose proved to form the disaccharide fucose-galactose in demilunar and acinar cells, whereas it was present with the sequence fucose-N-acetyl-D-glucosamine in striated duct cells. Sialic acid participated both to the terminal sequence sialic acid-galactose and sialic acid-N-acetyl-D-galactosamine either in demilunar or in ductal cells. Lectin labeling combined with glycosidase digestion was also helpful in verifying the influence of neighbouring oligosaccharides on the affinity of lectins for the respective sugars.
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PMID:Enzymatic degradation and quantitative lectin labeling for characterizing glycoconjugates which act as lectin acceptors in cat submandibular gland. 271 45

Flavonoids (103 species) were tested for inhibitory activity against mouse liver sialidase using sodium p-nitrophenyl-N-acetyl-alpha-D-neuraminate (PNP-NeuAc) as substrate. Isoscutellarein-8-O-glucuronide from the leaf of Scutellaria baicalensis showed most potent activity (IC50, 40 microM), and this flavone appeared to be a non-competitive inhibitor of the enzyme. This flavone inhibited the lysosomal solubilized sialidase against PNP-NeuAc and sialyllactose effectively, but not microsomal enzyme against gangliosides and colominic acid, whereas, negligible or weak inhibitory activities were observed for influenza virus sialidase, beta-galactosidase, alpha-mannosidase, and alpha-glucosidase tested. These results indicate that this flavone may be useful to elucidate the function of the lysosomal solubilized sialidase.
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PMID:Inhibition of mouse liver sialidase by plant flavonoids. 277 64

Purified preparations of herpes simplex virus type 1 Angelotti were digested with the exoglycosidases sialidase, beta-galactosidase, N-acetyl-beta-D-glucosaminidase and alpha-mannosidase, and with the endoglycosidases Endo-H and Endo-F. It was found that treatment of virions with Endo-F specifically decreased viral infectivity by a factor of 10. This reduction in titre was not associated with any measurable differences in virus adsorption, suggesting a role of N-linked complex type oligosaccharide chains in penetration. In contrast, a reduction in titre observed upon digestion of virions with exoglycosidases could be attributed to a proteolytic contamination in these enzyme preparations. Treatment of virions with Endo-H, demonstrated to be free of proteolytic contamination, did not reduce viral infectivity. Analysis of endoglycosidase-digested virions by monospecific antibodies and immunoblotting revealed a susceptibility of all four major glycoproteins (gC, gB, gE and gD) to Endo-F, but only gB was susceptible to Endo-H treatment. In contrast, of all the exoglycosidases used only sialidase was found to be active towards native viral glycoproteins. Upon analysis of endoglycosidase-digested virions we could not find any evidence for proteolysis, degradation or altered protein composition of viral envelopes. In contrast, vigorous inhibition of glycoprotein glycosylation by tunicamycin led to the formation of physically intact virions almost completely lacking all major glycoproteins. These data show that digestion of intact virions with glycosidases allows an analysis of the functional relevance of carbohydrate residues without any obvious alterations in the virion glycoprotein composition.
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PMID:Removal of N-linked carbohydrates decreases the infectivity of herpes simplex virus type 1. 284 61

Sialuria and sialidosis represent the two known types of genetic errors of sialic acid metabolism. Sialuria type I (or "massive Sialuria") remains a very rare disease, characterized by the daily excretion of 10 g of N-acetylneuraminic acid. Although the primary defect has not been established, the absence of a feedback inhibition of the anabolic reactions is probably involved in the massive production of free sialic acid. Sialuria type II (Salla disease) and type III are lysosomal storage diseases and the patients have shown to have a 10 to 15 fold increase in the amount of free sialic acid in urine. These sialurias probably involve a defect in translocation of sialic acid from lysosomes to the site of biosynthesis. The sialidase deficiency has been found to be responsible of a number of storage diseases previously unclassified or described as "lipomucopolysaccharidosis" or "mucolipidosis I". The sialidase deficiency, or Sialidosis, is characterized by and increased urinary excretion of sialyloligosaccharides and storage of sialylated compounds. A third type of genetic error, the combined beta-galactosidase-sialidase deficiency, is due to the genetic deficiency of a 32 KD "protective protein" which is part of the complex formed between multimeric beta-galactosidase and sialidase.
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PMID:[Genetic disorders of N-acetylneuraminic acid metabolism: sialurias and sialidoses]. 293 84


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