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)

We have previously reported an anti-fibronectin monoclonal antibody (mAb) (BC-1) which reacts with an ED-B-containing beta-galactosidase-fibronectin fusion protein but not with an identical beta-galactosidase-fibronectin fusion protein in which the ED-B sequence is omitted. In further experiments aimed at localizing more precisely the epitope recognized by this mAb, we demonstrate that 1) the mAb BC-1 is indeed specific for ED-B-containing fibronectin (FN) molecules even though the epitope recognized by this mAb is localized on the type III homology repeat 7 (the one which precedes the ED-B sequence) and 2) in fibronectin molecules lacking the ED-B sequence, this epitope is masked. We further demonstrate that, to mask the epitope recognized by the mAb BC-1, the presence of at least half of the FN type III homology repeat 9 is necessary. We also report the production of the mAb IST-6 which recognizes only FN molecules in which the ED-B sequence is lacking. These data clearly demonstrate that the presence of the ED-B sequence within FN molecules generates conformational modification in the central part of the molecules that unmasks previously cryptic sequences and masks others.
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PMID:The inclusion of the type III repeat ED-B in the fibronectin molecule generates conformational modifications that unmask a cryptic sequence. 128 Feb 66

The human 72-kDa (CLG4A) and 92-kDa (CLG4B) type IV collagenases contain a domain consisting of three contiguous copies of the fibronectin (FN)-derived type II homology unit (T2HU), T2HU-1, T2HU-2, and T2HU-3. To investigate the functional role of this domain, we have constructed plasmids expressing beta-galactosidase fusion proteins with one or more of the CLG4B-derived T2HU. The gelatin binding assays demonstrate that a single copy of T2HU-2 renders beta-galactosidase capable of binding gelatin. The three repeats, however, differ dramatically in their capacity to bind gelatin, with T2HU-1 and T2HU-3 having significantly less binding activity than T2HU-2. Using alanine scanning mutagenesis we have defined the amino acid residues (Arg307, Asp309, Asn319, Tyr320, Asp323) that are critical for gelatin binding of T2HU-2. The low gelatin binding of T2HU-1 compared to T2HU-2 was traced to the non-conserved residues Ala228-Ala and Leu253-Pro. The results suggest that the gelatin binding of the type IV collagenase proenzyme is mediated by the FN-like domain, although the presence of another gelatin-binding site cannot be excluded. The FN domain-mediated binding, however, is not a rate-limiting step in the hydrolysis of gelatin by the enzyme.
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PMID:Alanine scanning mutagenesis and functional analysis of the fibronectin-like collagen-binding domain from human 92-kDa type IV collagenase. 131 21

A protein (gal-FnBP), constructed by fusion of the genes encoding beta-galactosidase of Escherichia coli and the binding domains of fibronectin-binding protein (FnBP) of Staphylococcus aureus was used. FnBP is a surface protein responsible for attachment of bacteria to extracellular matrix of various host tissues. Gal-FnBP is more stable and can be produced in larger quantities than native FnBP. The binding specificity of this fusion protein was established in a Western blot analysis. Treatment of gal-FnBP with formalin inactivated the binding capacity of the protein but immunogenicity was retained. Immunisation of mice with formalin-treated gal-FnBP resulted in high antibody titres against the fibronectin-binding part of this fusion protein. These antibodies were measured by their ability to block the specific binding of fibronectin to gal-FnBP in a blocking assay. Sera raised against formalin-treated gal-FnBP and non-treated gal-FnBP blocked this binding to 40 and 25% respectively, thereby indicating the usefulness of gal-FnBP as a vaccine component.
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PMID:Immunological response to a Staphylococcus aureus fibronectin-binding protein. 146 Jun 56

Capillary endothelial cells can be induced to form capillary-like structures in vitro by plating on fibronectin-coated dishes (Ingber, D. E., and Folkman, J. (1989) J. Cell Biol. 109, 317-330), thereby mimicking angiogenesis. To assess the role of glycoproteins bearing asparagine-linked oligosaccharides in this process, we tested the effect of oligosaccharide processing inhibitors on the formation of capillary tubes. Deoxymannojirimycin, a compound that prevents synthesis of hybrid and complex-type oligosaccharides, inhibited the formation of capillary tubes. In contrast, swainsonine, an inhibitor that blocks synthesis of complex- but not hybrid-type oligosaccharides, did not inhibit tube formation. Lectin affinity chromatography of 2-[3H] mannose-labeled glycopeptides from endothelial cells induced to form tubes did not reveal a striking difference in the spectrum of oligosaccharides compared to uninduced cells. Since endothelial cells formed tubes normally in the presence of swainsonine, we analyzed glycopeptides from swainsonine-treated induced and uninduced cells. Cells induced to form tubes were enriched in monosialylated hybrid-type oligosaccharides sensitive to alpha-fucosidase, beta-galactosidase, and beta-N-acetylhexosaminidase, suggestive of sialyl Lewis-X determinants. We used an enzyme-linked immunoassay to measure sialyl Lewis-X epitopes on capillary endothelial cells and found that both induced and uninduced cells expressed sialyl Lewis-X epitopes. Deoxymannojirimycin and, to a lesser extent, swainsonine reduced the level of sialyl Lewis-X epitopes in cells induced to form capillary tubes, but neither compound affected the level of epitopes in cell monolayers. We conclude that synthesis of at least hybrid-type oligosaccharides is required for capillary tube formation in vitro and that an increase in monosialylated, fucosylated glycans on asparagine-linked oligosaccharides occurs during this process.
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PMID:1-Deoxymannojirimycin inhibits capillary tube formation in vitro. Analysis of N-linked oligosaccharides in bovine capillary endothelial cells. 146 26

In order to clarify the relationship between hydrolases and the invasion of gastric carcinoma, both fibronectin and proteoglycan in pericancerous matrix and beta-galactosidase activity in gastric carcinoma were investigated by means of histochemical, immunohistochemical and ruthenium red electrocytochemical stains. The results showed that the activity of beta-galactosidase in mucous cell carcinoma was more intensive than that in well-differentiated and poorly-differentiated adenocarcinoma. RR granules and fibronectin were not found in the pericancerous matrix close to the mucous cell carcinoma, but were obtained in the region far from the mucous cell carcinoma. Nevertheless, both of them were present and intact near the well-differentiated adenocarcinoma. The result of this study suggests that mucous cell carcinoma may secrete beta-galactosidase into the surrounding matrix, inducing degradation of proteoglycan and fibronectin in favour of further infiltration and metastasis.
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PMID:[The relationship between hydrolases and invasion of gastric carcinoma]. 166 9

The NILE glycoprotein is a rat neuronal cell adhesion molecule which has been reported to be very similar in structure, function, and distribution to the mouse L1 glycoprotein. Here we report the complete nucleotide sequence of the NILE message (5,208 nucleotides) and the deduced amino acid sequence of the NILE polypeptide (1,257 amino acids). The predicted NILE protein is 96% identical to L1 at the amino acid level, confirming that the two molecules are homologues. The sequence information shows that NILE is a transmembrane molecule with an extensive ectodomain and a much smaller cytoplasmic domain. The extracellular portion of the molecule contains six immunoglobulin C-2 type domains followed by five fibronectin type III repeats. These two structural motifs are characteristic of several other cell adhesion molecules. The cytoplasmic tails of NILE and L1 are identical to each other and distinct from the cytoplasmic regions of all other cell adhesion molecules except Ng-CAM and neuroglian. Several possible sites for phosphorylation are present in the cytoplasmic tail of NILE. Antisera were produced against two NILE-beta-galactosidase fusion proteins containing distinct segments of the NILE polypeptide: the cytoplasmic domain and the segment containing fibronectin type III repeats. Immunoblots with these antisera and Northern blots with a NILE cDNA probe indicate that NILE continues to be expressed in most areas of the mature rat brain. This contradicts previous immunofluorescence data, which suggested that NILE was substantially down-regulated in maturing nerve fiber tracts. This raises the possibility that NILE could be masked in situ by interactions with other cell surface molecules.
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PMID:Molecular cloning of NILE glycoprotein and evidence for its continued expression in mature rat CNS. 180 Jul 73

The fibronectin-related region of the 72 kDa type IV procollagenase has been expressed in E. coli as a beta-galactosidase fusion product. The fragment containing the three type II units of the protein was found to have affinity for denatured collagen, suggesting that these domains may be responsible for the collagen-affinity of type IV collagenase. We have also shown that segment Ala-Ala-His-Glu of type IV collagenase (residues 372-375), which is similar to a fibronectin-segment previously implicated in collagen-binding, is not essential for binding activity.
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PMID:Evidence for the involvement of type II domains in collagen binding by 72 kDa type IV procollagenase. 185 Nov 8

A single type-II domain has been isolated by limited proteolysis of the collagen-binding bovine seminal fluid protein, PDC-109. The 45-residue fragment corresponding to the second type-II domain of the parent molecule was found to have retained affinity for immobilized collagen, indicating that this minidomain carries critical regions of the collagen-binding site. Studies on various fragments of fibronectin have also implicated the two type-II units of this molecule in collagen-binding. In the present work we have found that type-II domains of human fibronectin, expressed in Escherichia coli as beta-galactosidase fusion proteins, bind specifically to immobilized collagen.
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PMID:The collagen-binding site of type-II units of bovine seminal fluid protein PDC-109 and fibronectin. 224 94

Here we report on a monoclonal antibody (IST-9) which distinguishes between human cellular and plasma fibronectin. Using beta-galactosidase-fibronectin fusion proteins expressed in E. coli we have demonstrated that this monoclonal antibody is specific for a fibronectin segment (ED) which can be included or omitted from the molecule depending on the pattern of splicing of the mRNA precursors. Furthermore, using the same fusion proteins we have been able to localize precisely the epitopes of two other monoclonal antibodies (IST-1 and IST-2), specific for the heparin-binding domain 5 of fibronectin.
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PMID:Localization of the cellular-fibronectin-specific epitope recognized by the monoclonal antibody IST-9 using fusion proteins expressed in E. coli. 243 58

Antibody titres against fibronectin-binding protein (FnBP) of Staphylococcus aureus were determined in sera from rabbits immunized with staphylococcal whole cells or purified native fibronectin receptor. An ELISA technique for detection of antibody titres blocking the binding of soluble fibronectin to immobilized FnBP was developed. A recombinant staphylococcal FnBP fused to E. coli beta-galactosidase (gal-FnBp) was used as the immobilized antigen in this test. Serum samples from two different rabbits immunized with native fibronectin receptor gave significant blocking titres, whereas the blocking titres of antisera against staphylococcal whole cells were about 4- to 5-fold lower. Using the gal-FnBP fusion protein, the sensitivity for detection of fibronectin by ELISA was also determined. The detection limit is around 5 ng. The findings are discussed with a view to developing an anti-staphylococcal adherence vaccine and quantitating fibronectin in solution.
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PMID:Detection in rabbit sera of blocking antibodies against staphylococcal fibronectin-binding protein by enzyme-linked immunosorbent assay. 253 53


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