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)

1. Two "acid" forms, Am and Al, of beta-galactosidase from sheep kidney have been isolated and purified 349- and 154-fold, respectively, with a recovery of about 8%. 2. Their mol. wts were about 450,000 and 230,000, respectively. Am seems to be a dimer of Al. The aggregation is stimulated by NaCl. 3. The "acid" beta-galactosidase has a pH optimum between 4.0 and 5.0 for both forms. They are located in the lysosomes. The optimal temperature is 37 degrees C and 40 degrees C for Al and Am forms, respectively. 4. Three peaks were detected by isoelectric focusing. After sialidase treatment, these peaks were obtained at higher pH values. 5. The activation energy values were 10.75 and 11.72 kcal/mol for Am and Al, respectively. 6. A variety of chemicals were tested as possible activators or inhibitors. The enzyme is strongly inhibited by gamma-D-galactonolactone, and the kinetic evidence suggests a competitive inhibition in all cases.
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PMID:Purification and characterization of different "acid" beta-galactosidases from sheep kidney. 176 16

Sialic acid-containing carbohydrates were isolated from sialidosis urine by a combination of gel-filtration on Bio-Gel P-6 and medium-pressure anion-exchange chromatography on Mono Q. The Mono Q fractions were subjected to 500-MHz 1H-NMR spectroscopy, sugar analysis and analytical HPLC on Lichrosorb-NH2. These methods indicated the presence of various N-acetyllactosamine type sialyloligosaccharides differing from each other in branching pattern and sialic acid linkage types. Among the structures were fully and partially sialylated mono-, di-, tri- and tetra-antennary compounds. A comparison with the results from galactosialidosis urine indicated that essentially the same carbohydrates were present in both urines, but that the relative amounts of the various sialyloligosaccharides differ to some extent. Sialidosis urinary oligosaccharides contained relatively more alpha 2-6 linked sialic acid than oligosaccharides from galactosialidosis urine. It could be concluded that the additional beta-galactosidase deficiency in galactosialidosis did not influence the nature of the excreted material and that the sialidase deficiency determined completely the defective catabolism of glycoproteins in both sialidosis and galactosialidosis.
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PMID:A comparative study of sialyloligosaccharides isolated from sialidosis and galactosialidosis urine. 177 19

Sialidase isolated from human placenta is associated with several proteins including acid beta-galactosidase, carboxypeptidase, N-acetyl-alpha-galactosaminidase, and others. These proteins are thought to form an aggregated complex during isolation of sialidase. One of the proteins of 60 kDa was recently identified by Potier et al. (Biochem. Biophys. Res. Comm. 173, 449-456, 1990) as a sialidase protein: this protein also cross-reacted with anti-prosaposin antibodies. We have isolated this protein and from the following evidence identified it as a heavy chain component of immunoglobulin G and not sialidase or a derivative of prosaposin. On gel filtration HPLC, sialidase activity and the 60 kDa protein were clearly separated from one another. The 60 kDa protein cross-reacted not only with antibodies raised against human saposins A, C, and D, but also with second antibody (goat anti-rabbit immunoglobulin G antibody) alone. This 60 kDa protein strongly cross-reacted with anti-human immunoglobulin G antibodies. The sequence of the initial 15 amino acids from the N-terminus of the 60 kDa protein was identical to the sequence of an immunoglobulin G heavy chain protein Tie (gamma 1).
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PMID:Human placental sialidase complex: characterization of the 60 kDa protein that cross-reacts with anti-saposin antibodies. 190 36

A brief (30 min) treatment of mouse peritoneal cells (mixture of nonadherent lymphocytes and adherent macrophages) with 1-20 micrograms of lysophosphatidylcholine (lyso-PC) per ml in serum-supplemented RPMI medium 1640, followed by a 3-hr cultivation of the adherent cells alone, results in a greatly enhanced Fc receptor-mediated phagocytic activity of macrophages. This rapid process of macrophage activation was found to require a serum factor, the vitamin D3 binding protein (the human protein is known as group-specific component; Gc). Efficient activation of macrophages was achieved by using medium containing purified human Gc protein. Analysis of intercellular signal transmission among nonadherent (B and T) cells revealed that lyso-PC-treated B cells modify Gc protein to yield a proactivating factor, which can be converted by T cells to the macrophage-activating factor. This rapid generation process of the macrophage-activating factor was also demonstrated by stepwise incubation of Gc protein with lyso-PC-treated B-cell ghosts and untreated T-cell ghosts, suggesting that Gc protein is modified by preexisting membranous enzymes to yield the macrophage-activating factor. Incubation of Gc protein with a mixture of beta-galactosidase and sialidase efficiently generated the macrophage-activating factor. Stepwise incubation of Gc protein with B- or T-cell ghosts and sialidase or beta-galactosidase revealed that Gc protein is modified by beta-galactosidase of B cells and sialidase of T cells to yield the macrophage-activating factor. Administration to mice of a minute amount (4-10 pg per mouse) of in vitro, enzymatically generated macrophage-activating factor resulted in a greatly enhanced (3- to 7-fold) ingestion activity of macrophages.
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PMID:Vitamin D3 binding protein (group-specific component) is a precursor for the macrophage-activating signal factor from lysophosphatidylcholine-treated lymphocytes. 192 12

1. The sialidase purified from the hepatopancreas of Penaeus japonicus is able to bind the acidic beta-galactosidase in vitro. No protective protein, Mr 32,000, was detected in either purified enzyme preparation. 2. The specific activity of the isolated sialidase is 55.0 mU/mg of protein. After polyacrylamide gel electrophoresis under denaturing conditions, the purified shrimp enzyme was found to consist of monomers of Mr 32,000. 3. The sialidase from shrimp has an isoelectric point (pI) of 4.6 +/- 0.1. 4. The shrimp enzyme has the pH optimum at 5.0 and its Km was 5.5 microM with 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid as substrate. The enzyme activity was inhibited by either Hg2+ or Cu2+ ions.
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PMID:A sialidase from the hepatopancreas of the shrimp Penaeus japonicus (Crustacea: Decapoda): reversible binding with the acidic beta-galactosidase. 198 76

Lysosomal neuraminidase (sialidase; EC 3.2.1.18) and beta-galactosidase (EC 3.2.1.23), together with a carboxypeptidase, the so-called 'protective protein', were co-purified from the human placenta by affinity chromatography on a concanavalin A-Sepharose column followed by a thiogalactoside-agarose affinity column for beta-galactosidase. Analysis of the purified material by gel-filtration h.p.l.c. revealed three distinct molecular forms, all with high beta-galactosidase specific activity, but only the largest one expressed neuraminidase activity. Rechromatography of each individual species separately indicated that all three are in fact part of an equilibrium system (the neuraminidase-beta-galactosidase-carboxypeptidase complex or NGC-complex) and that these species undergo slow conversion into one another through dissociation and association of protomeric components. Each species was sufficiently stable for the determination of their hydrodynamic properties by gel-filtration h.p.l.c. and sedimentation velocity. The largest species had an apparent sedimentation coefficient S20.w, of 18.8 S and a Stokes' radius of 8.5 nm, giving a molecular mass of 679 kDa and a fractional ratio, f/f min, of 1.47. The latter value indicates that the macromolecule is asymmetric or highly hydrated. This large species is composed of four types of polypeptide chains of molecular mass 66 kDa (neuraminidase), 63 kDa (beta-galactosidase), 32 kDa and 20 kDa (carboxypeptidase heterodimer). The 32 kDa and 20 kDa protomers are linked together by a disulphide bridge. Glycopeptidase F digestion of the NGC-complex transformed the diffuse 66-63 kDa band on the SDS gel into two close but sharp bands at 58 and 56 kDa. The two smaller species which were separated on the h.p.l.c. column correspond to tetrameric and dimeric forms of the 66-63 kDa protomers and express exclusively beta-galactosidase activity. Treatment of the NGC-complex with increasing concentrations of guanidinium hydrochloride up to 1.5 M also resulted in dissociation of the complex into the same smaller species mentioned above plus two protomers of molecular mass around 60 and 50 kDa. A model of the largest molecular species as a hexamer of the 66-63 kDa protomers associated to five carboxypeptidase heterodimers (32 kDa and 20 kDa) is proposed
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PMID:Structure of the lysosomal neuraminidase-beta-galactosidase-carboxypeptidase multienzymic complex. 210 3

An increased resistance of laboratory animals to pulmonary infections following per os administration of a glyco-proteic complex extracted from Klebsiella pneumoniae has been reported. This was associated with an increased phagocytic capacity of alveolar macrophages (AM). In this report, the effect of treating guinea pigs with this extract on the alveolar macrophage (AM) glycosidase machinery has been studied. AM were collected by bronchoalveolar lavage, the cells were pelleted by centrifugation and AM were purified by adherence on plastic dishes. Sialidase, beta-galactosidase, beta-glucuronidase and N-acetyl-beta-D glucosaminidase activities were measured in the AM homogenate. In order to evaluate an extracellular release of these enzymes, they were also assayed in the cell free lavage fluid. Lactic dehydrogenase (LDH) activity was assayed as a control for cell lysis. In treated animals, the total number of cells as well as the number of AM increased by 25% (ns). The protein concentration was slightly reduced in the cell homogenate and unchanged in the lavage fluid. The only significant change was a decreased sialidase activity, in AM homogenate (p less than or equal to 0.01) and in lavage fluids (ns). The LDH activity was not increased in the lavage fluids.
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PMID:Glycosidase activities in alveolar macrophages from guinea pigs stimulated with a glyco-proteic complex extracted from Klebsiella pneumoniae. 212 66

Previous studies have shown that plasma membrane compounds are involved in the contact-dependent inhibition of growth of human diploid fibroblasts. The purification of the active plasma membrane glycoprotein is described in this report. The glycoprotein has an apparent molecular mass of 60-70 kD and, due to differential sialylation, isoelectric points between pH 5.5. and 6.2. Treatment with sialidase yielded one spot in two-dimensional gel electrophoresis with an isoelectric point of 6.3. After removal of the N-glycosidically linked oligosaccharide chains, the apparent molecular mass is reduced by approximately 22 kD. Treatment was diluted NaOH, which removes the O-glycosidically linked portion of oligosaccharides, resulted in a reduction of the apparent molecular mass by approximately 5 kD. The addition of 50 ng/ml of this glycoprotein-for which the term "contactinhibin" is proposed-in immobilized form to sparsely seeded human fibroblasts resulted in a reversible 70-80% inhibition of growth. The inhibition was not confined to human fibroblasts as other cells were also inhibited, with the exclusion of transformed cells, which are refractory to contactinhibin. The inhibitory activity was abolished by treatment with beta-galactosidase or glycopeptidase F, indicating that the glycan moiety is the biologically active part of the molecule. Confluent cultures treated with antibodies raised against contactinhibin were released from the contact-dependent inhibition of growth. In addition to enhanced saturation density, these cultures exhibited a crisscross growth pattern and the formation of foci. Immunocytochemical studies showed that contactinhibin was associated with vimentin. Furthermore, contactinhibin was found to be not expressed in a species- or organ-specific manner.
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PMID:Isolation and characterization of a 60-70-kD plasma membrane glycoprotein involved in the contact-dependent inhibition of growth. 227 80

The antigen designated as Chol-1 beta, detected by an antiserum specific for cholinergic neurons, has been purified to homogeneity from ganglioside mixtures extracted from Torpedo electric organ and pig brain. The final products from the two sources behaved identically in a wide range of tests and gave coincident immunopositive and Ehrlich-positive spots after thin layer chromatography in seven different solvent systems; they were thus considered to be identical and to constitute a single, pure chemical species. Gas-chromatographic analysis revealed the presence of long-chain bases, glucose, galactose, N-acetylgalactosamine, and sialic acid in integral molar ratios of 1:1:2:1:3; the compound's reactivity to cholera toxin after Vibrio cholerae sialidase treatment on thin layer chromatography and the recovery of GM1 as sole product of exhaustive sialidase treatment identified it as a member of the gangliotetrahexosyl series. From the products of partial enzymatic desialylation and treatment with beta-galactosidase and a comparison of the compound's immunoreactivity to anti-Chol-1 antisera with that of other trisialogangliosides of defined molecular structure, we were able to assign a disialosyl residue alpha-Neu5Ac-(2----8)-alpha-Neu5Ac-(2----3)- to the inner galactose, and we suggest GalNAc as a possible site of linkage of the third sialic acid.
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PMID:Further studies on the gangliosidic nature of the cholinergic-specific antigen, Chol-1. 235 21

A biochemical scheme was developed by which strains of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus can reliably be distinguished from within the "Streptococcus milleri group." Strains identified as S. intermedius were differentiated by the ability to produce detectable levels of alpha-glucosidase, beta-galactosidase, beta-D-fucosidase, beta-N-acetylgalactosaminidase, beta-N-acetylglucosaminidase, and sialidase with 4-methylumbelliferyl-linked fluorogenic substrates in microdilution trays after 3 h of incubation at 37 degrees C, together with the production of hyaluronidase. Strains of S. constellatus and S. anginosus were differentiated by the production of alpha-glucosidase and hyaluronidase by the former and the production of beta-glucosidase by the latter. The majority of strains of the S. milleri group obtained from dental plaque were identified as S. intermedius, as were most strains isolated from abscesses of the brain and liver. Strains of S. constellatus and S. anginosus were from a wider variety of infections, both oral and nonoral, than were strains of S. intermedius, with the majority of strains from urogenital infections being identified as S. anginosus.
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PMID:Phenotypic differentiation of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus strains within the "Streptococcus milleri group". 238 Mar 75


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