Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An enzyme preparation from embryonic chicken brain catalyzes the transfer of sialic acid from CMP-N-acetylneuraminic acid to ceramide-Glc-Gal(NeuAc-NeuAc)-GalNAc-Gal (GDlb) to form ceramide-Glc-Gal(NeuAc-NeuAc)-GalNAc-Gal-NeuAc (GTlb). The sialyltransferase activity was measured during the development of the embryo, the subcellular distribution of this activity was determined and several kinetic properties of the reaction were examined. A comparative study with the similar reaction involved in the transfer of sialic acid to the terminal galactose in ceramide-Glc-Gal(NeuAc)-GalNAc-Gal (GMl) was made. The results obtained in this comparative study suggest that the transfer of sialic acid in both reactions is catalyzed by the same enzyme.
Mol Cell Biochem 1977 Jul 05
PMID:Trisialoganglioside synthesis by a chicken brain sialyltransferase. Comparative study with the similar reaction for the synthesis of disialoganglioside. 1 68

The elevated level of lactose carrier protein present in cytoplasmic membranes derived from Escherichia coli strain T31RT, which carries the Y gene of the lac operon on a plasmid vector (Teather, R. M., et al. (1978) Mol. Gen. Genet. 159, 239--248), has allowed the detection of a complex between the carrier and the fluorescent substrate 2'-(N-dansyl)-aminoethyl beta-D-thiogalactopyranoside (Dns2-S-Gal). Binding is accompanied by a 50-nm blue shift in the emission maximum of the dansyl residue. The complex (dissociation constant, KD = 30 micron) rapidly dissociates upon addition of competing substrates such as beta-D-galactopyranosyl 1-thio-beta-D-galactopyranoside or upon reaction with the thiol reagent p-chloromercuribenzenesulfonate. Binding of both Dns2-S-Gal and p-nitrophenyl alpha-D-galactopyranoside (alpha-NPG) occurs spontaneously in the absence of an electrochemical potential gradient across the membrane. Comparison of equilibrium binding experiments using Dns2-S-Gal or alpha-NPG and differential labeling of the carrier with radioactive amino acids shows that the carrier binds 1 mol of substrate per mol of polypeptide (molecular weight 30 000). In addition to specific binding to the lactose carrier, Dns2-S-gal binds unspecifically to lipid vesicles or membranes, as described by a partition coefficient, K = 60, resulting in a 25-nm blue shift in the emission maximum of the dansyl group. Both Dns2-S-Gal and alpha-NPG are not only bound by the lactose carrier but also transported across the membrane by this transport protein in cells and membrane vesicles. The fluorescence changes observed with dansylated galactosides in membrane vesicles in the presence of an electrochemical gradient (Schuldiner et al. (1975) J. Biol. Chem. 250, 1361--1370)) are interpreted as an increase in unspecific binding after translocation.
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PMID:Lactose carrier protein of Escherichia coli. Transport and binding of 2'-(N-dansyl)aminoethyl beta-D-thiogalactopyranoside and p-nitrophenyl alpha-d-galactopyranoside. 36 91

IS2-induced deletions of the gal control region were isolated in a plasmid carrying gal OP-308::IS2-7. This contains a 54 basepair long, unstable mini insertion within IS2, thus allowing constitutive expression of the gal structural genes. Deletion PPI is 11.9 kilobasepairs (kb) long and is Gal+ because it has retained the mini insertion. In PP4 7.2 kb DNA material including markers gal OP, chlD and pgl are deleted. PP4 has lost the mini insertion and is therefore Gal negative. DNA sequencing of the newly formed junction in PP4 reveals that the deletion terminates precisely at nucleotide 1 of IS2 and that no DNA sequence homology is involved in this IS2-mediated deletion formation. PPI segregates Gal- clones due to the loss of the mini insertion. One such segregant PPIS and PP4 both give only constitutive Gal+ revertants, which consist of the previously known mini insertions and also a new class of "supermini" inserts within IS2 of about 10 to 20 basepairs long. Therefore, PPIS and PP4 can be used to study various parameters involved in the formation of mini insertions.
Mol Gen Genet 1979 May 23
PMID:Development of a system useful for studying the formation of unstable alleles of IS2. 38 39

The Gal+ allele IS2-43 is known to segregate Gal- clones. Among 11 Gal- segregants, one was shown to be due to the integration of IS3 into IS2-43. Precise excision of the integrated IS3 element occurred at a rate of 5 x 10(-9)/cell/generation. DNA sequence analysis revealed that the termini of the IS3 element have the relation of imperfect inverted repeats and it is now flanked by a 3bp or 4bp duplication, a size which has not been seen before with other elements.
Mol Gen Genet 1979
PMID:Integration of IS3 into IS2 generates a short sequence duplication. 39 17

Escherichia coli strains bind to Gal alpha 1-4Gal-containing glycolipids via P pili-associated G-adhesins. Three functional classes of adhesins with different binding specificities are encoded by conserved G-alleles. We suggest that the Class I papG-allele of strain J96 is a novel acquisition possibly introduced via horizontal gene transfer into one of the two P pili gene clusters carried by this strain. Closely related strains in the ECOR collection of natural E. coli isolates carry either a Class II or a Class III G-adhesin. Data indicate that genetic exchanges involving either entire pap or prs gene clusters or individual pap/prs genes have occurred. We propose that the retention and spread of pap/prs DNA among E. coli is the result of selection pressure exerted by mammalian intestinal isoreceptors.
Mol Microbiol 1992 Aug
PMID:Horizontal gene transfer of the Escherichia coli pap and prs pili operons as a mechanism for the development of tissue-specific adhesive properties. 135 26

A comparative survey was undertaken of the neutral fraction glycolipids from the metacestodes of 3 taeniid species, Taenia crassiceps, Taenia solium and Taenia saginata, to determine their chemical and serological staining patterns on separation by thin-layer chromatography. The orcinol-positive patterns of T. solium and T. saginata metacestodes exhibited a closer superficial resemblance to each other than to T. crassiceps or T. saginata adults. A comparison of component migration properties against standards of known structure indicated the main oligosaccharide chains to be mono-, di-, tri- and tetrasaccharides; however, in T. solium this was extended to at least a heptasaccharide. The multiple banding characteristic of each component is a consequence of lipid moiety heterogeneity. Serologically, the patterns of the 3 taeniid species neutral fraction glycolipids showed virtually the same immunological reactivity towards mouse normal serum, infection serum and a monospecific, polyclonal antibody directed against the trisaccharide component of T. crassiceps. The latter antibody was isolated from mouse infection serum by affinity chromatography on a column of glycolipid-bound octyl-Sepharose CL-4B. Immunochemically, the major common epitope expressed by the neutral fraction glycolipids of the 3 taeniid species is the same or very similar to the glycosphingolipid, neogalatriaosyl ceramide derived from the marine mollusc Turbo cornutus (Gal(beta 1-6) Gal(beta 1-6) Gal(beta 1-1)Cer). Host tissue neutral fraction glycolipids, porcine muscle and bovine muscle, as well as human spleen, were not immunoreactive.
Mol Biochem Parasitol 1992 Jul
PMID:Comparative serological reactivity of Taenia crassiceps, Taenia solium and Taenia saginata metacestode neutral glycolipids to infection serum from Taenia crassiceps-infected mice. 138 Jan 26

Ovalbumin (OVA) is a major allergen (Gal d II) of hen egg white and is often the cause of hypersensitivity reactions to food. Further knowledge of the antigenic and allergenic epitopes of allergens will provide better treatment of this disease. To analyse these epitopes we produced a panel of monoclonal antibodies (mAbs) against native OVA. The initial information about the epitopes was obtained with the binding patterns of these mAbs in IEF-immunoprints and western blots of OVA under reducing and non-reducing conditions. It was possible to demonstrate that the different conformations of OVA exhibit different epitopes, and that there are other epitopes which are shared by each conformation. Seven different, although sometimes overlapping epitopes, could be determined on native OVA; four different epitopes on denaturated non-reduced OVA by means of immunoblots of the intact molecule. The number of epitopes which could be differentiated by the mAbs was increased by the use of peptide blots after CNBr fragmentation of the molecule. IgE binding to different OVA conformations and to CNBr-fragments of OVA was also detectable and appears in the same regions as the reactivity of some mAbs. Western blots of OVA and CNBr-peptides demonstrate that some antigenic/allergenic binding sites seem at least partly to be continuous epitopes. The identification of the CNBr-fragments was performed by a microsequence analysis of blotted CNBr-fragments after a 2-dimensional electrophoresis. IgE was found to bind the two largest CNBr-fragments (residues 41-172 and 301-385), but not the fragment corresponding to residues 173-196. A number of monoclonal antibodies also reacted with the two large fragments, especially with fragment 301-385, and some bind also to shorter peptides, such as fragment 173-196, which were not reactive to patients' IgE. Most of the monoclonal antibodies and patients' IgE bind to the fragments 41-172 and 301-385 in 2D-PAGE blots suggesting that these fragments are involved in an immunogenic structure.
Mol Immunol 1992 Oct
PMID:Epitope analysis of the allergen ovalbumin (Gal d II) with monoclonal antibodies and patients' IgE. 138 20

We previously reported the analysis of recombinant plasmids from Haemophilus influenzae type b (Hib) that lead to modifications of Escherichia coli lipopolysaccharide (LPS) (Y. Abu Kwaik, R. E. McLaughlin, M. A. Apicella, and S. M. Spinola, Mol. Microbiol. 5:2475-2480, 1991). The modified LPS species are recognized by monoclonal antibodies (MAbs) 6E4 and 3F11. MAb 6E4 binds to a stable 2-keto-3-deoxyoctulosonic acid epitope, while MAb 3F11 binds to a Gal beta 1-4GlcNac epitope that phase varies in Hib at a frequency of 2 to 5%. The internal EcoRI fragment containing most of the DNA required for LPS modification in E. coli was used as the target for transposon mutagenesis. Plasmids containing minitransposon m-Tn3(Cm) randomly inserted into the target fragment were transformed into the isogenic Hib strain, and transposon integration into the Hib chromosome was verified by colony hybridization. The lipooligosaccharides of 36 transformants were phenotypically and antigenically characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reactivity with a variety of MAbs that recognize both stable and phase-varying lipooligosaccharide epitopes. The majority of the mutants had altered reactivity with MAb 6E4. With one exception, these mutants retained the ability to express phase-varying epitopes. Analysis of the transformants suggested that the 6E4 epitope was contained on an oligosaccharide chain separate from that of phase-varying epitopes and appeared to be assembled in at least three separate steps.
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PMID:Generation of lipooligosaccharide mutants of Haemophilus influenzae type b. 140 Jan 98

An acidic glycoconjugate could be extracted from a delipidated residue fraction of [3H]galactose, [3H]mannose or [32P]orthophosphate metabolically labeled Entamoeba histolytica with water/ethanol/diethylether/pyridine/NH4OH (15:15:5:1:0.017). The radioactively labeled glycoconjugate comprised 50-55% of the total [3H]galactose label incorporated into macromolecules. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the radiolabeled glycoconjugate showed two diffuse smears centering around 110 kDa and 45 kDa. Similar profiles were observed for both [3H]galactose- and [32P]orthophosphate-labeled glycoconjugate. No such bands were visible in [35S]methionine-labeled material. The hydrophobic nature of this glycoconjugate was inferred from its chromatographic behavior on phenyl-Sepharose. The molecule was rendered hydrophilic after digestion with phosphatidylinositol-specific phospholipase C. It was also sensitive to deamination by nitrous acid. Mild acid hydrolysis led to its fragmentation into smaller molecules as revealed by Sepharose 4B chromatography. Paper chromatographic analysis of the depolymerized [3H]galactose- and [3H]mannose-labeled fragments revealed that each was sensitive to alkaline phosphatase. The major dephosphorylated fragment migrated as an apparent galactose and mannose containing disaccharide which migrated identically to the Gal beta 1-4Man disaccharide derived from the lipophosphoglycan of Leishmania donovani. The above data support the existence of a major acidic glycoconjugate in E. histolytica bearing striking structural similarities to the lipophosphoglycan of Leishmania.
Mol Biochem Parasitol 1992 Nov
PMID:Identification and partial characterization of a lipophosphoglycan from a pathogenic strain of Entamoeba histolytica. 147 94

It has been reported that natural antibodies alter aging RBCs, so increasing their vulnerability for removal from the blood stream. Results presented indicate that binding of anti-Gal, a natural antibody, to erythrocytes increases RBC rigidity in terms of microviscosity and deformability. Removal of RBCs from circulation could, at least in part, depend on these alterations.
Cell Mol Biol (Noisy-le-grand)
PMID:Modification of RBC properties by an autoantibody. Binding to RBC senescent antigen. 148 10


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