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)

A 16 kDa Schistosoma mansoni schistosomular surface antigen (Sm16) was originally described as the target of a passively protective mAb (B3A). It appeared on the schistosomular surface after transformation of cercariae and was uniquely recognised by sera from animals exposed to attenuated cercariae. In this work sequential extractions of schistosomula with Triton X-114 and sodium dodecyl sulphate showed Sm16 to be an integral membrane structure which did not appear to be glycosylphosphatidylinositol-anchored as judged by experiments using phosphatidyl inositol-specific phospholipase C. The antigen was strongly reactive in Western blotting with rabbit irradiated vaccine sera. Sm16 was demonstrated in the hepatopancreas of S. mansoni-infected snails and was equally abundant in cercariae and mechanically- transformed schistosomula but was undetected in liver stage worms or eggs. Immunoelectron microscopy showed Sm16 to be localised, in cercariae, to what are believed to be subtegumental cell bodies packed with membraneous vesicles. Treatment with proteases and with sodium metaperiodate showed Sm16 to be a glycoprotein of which the epitope recognised by B3A was periodate sensitive. Two-dimensional electrophoresis gave a PI of 6. Neither the size or the recognition by B3A was affected by treatment with N-glycosidase F, endoglycosidase F or endo-alpha-N-acetylgalactosaminidase. Western blotting using a wide range of biotinylated lectins showed recognition only by peanut agglutinin and Ricinus communis agglutinin II (ricin). It is concluded that Sm16 has antigenic surface-exposed O-linked complex oligosaccharides which lack mannose/glucose, GlcNAc, L-fucose and sialic acid but contain terminal Gal beta (1-3) GalNAc and/or galactose.
Mol Biochem Parasitol 1999 May 15
PMID:Characterization of a stage-specific Mr16000 schistosomular surface glycoprotein antigen of Schistosoma mansoni. 1037 96

The mucopolysaccharidoses (MPS) are a group of multiple pathology disorders which are part of a larger group of genetic diseases known as lysosomal storage disorders. Enzyme replacement therapy (ERT) has been developed as a therapy for MPS patients. However, immune responses to ERT have been reported in MPS animal models and in human Gaucher patients. Antibodies can have adverse effects during ERT, which include hypersensitivity/anaphylactic reactions, enzyme inactivation, and enzyme degradation. This study aimed to characterize the immune response to ERT in a feline model of MPS VI, by defining the epitope reactivity of cat plasma antibody against human recombinant N-acetylgalactosamine 4-sulfatase (4-sulfatase) replacement protein. For MPS VI cat plasma, antibody reactivity was observed prior to ERT, with distinct regions of 4-sulfatase linear sequence displaying low affinity antibody reactivity. There was an increase in antibody titer to 4-sulfatase for MPS VI cats post-ERT, with the majority of the immune response detected to linear sequence epitopes. One cat displayed a high titer and high affinity epitope reactivity following prolonged exposure (>/=9 months) to the replacement protein. MPS VI cats on shorter term ERT (3 months) showed high titers to 4-sulfatase and similar patterns of epitope reactivity, but lower affinity antibody reactivity, when compared to the latter cat. This study reports the linear amino acid sequence reactivity and nature of the immune response produced to 4-sulfatase before and after ERT. The monitoring of antibody production during replacement therapy is an important consideration for patient management, as high titer antibodies can affect the efficacy of therapy.
Mol Genet Metab 1999 Jul
PMID:Immune response to enzyme replacement therapy: 4-sulfatase epitope reactivity of plasma antibodies from MPS VI cats. 1038 27

Streptococcus thermophilus Sfi6 produces an exopolysaccharide (EPS) composed of glucose, galactose and N-acetylgalactosamine in the molar ratio of 1:2:1. The genes responsible for the EPS biosynthesis have been isolated previously and found to be clustered in a 14.5 kb region encoding 13 genes. Transfer of this gene cluster into a non-EPS-producing heterologous host, Lactococcus lactis MG1363, yielded an EPS with a similar high molecular weight, but a different structure from the EPS from the native host. The structure of the recombinant EPS was determined by means of 1H homonuclear and 1H-13C heteronuclear two-dimensional nuclear magnetic resonance (NMR) spectra and was found to be --> 3)-beta-D-Glcp-(1 --> 3)-alpha-D-Galp-(1 --> 3)-beta-D-Galp-(1 --> as opposed to --> 3)[alpha-D-Galp-(1 --> 6)]-beta-D-Glcp-(1 --> 3)-alpha-D-GalpNAc-(1 --> 3)-beta-D-Galp-(1 --> for the wild-type S. thermophilus Sfi6. Furthermore, L. lactis MG1363 (pFS101) was also lacking a UDP-N-acetylglucosamine C4-epimerase activity, which would provide UDP-GalNAc for a GalNAc incorporation into the EPS and probably caused the substitution of GalNAc by Gal in the recombinant EPS. This modification implies that (i) bacterial glycosyltransferases could potentially have multiple specificities for the donor and the acceptor sugar molecule; and (ii) the repeating unit polymerase can recognize and polymerize a repeating unit that differs in the backbone as well as in the side-chain from its native substrate.
Mol Microbiol 1999 Jun
PMID:Introduction of the exopolysaccharide gene cluster from Streptococcus thermophilus Sfi6 into Lactococcus lactis MG1363: production and characterization of an altered polysaccharide. 1038 68

A lectin was isolated from the mycelium of the stationary growing enthomopathogenic fungus Beauveria bassiana by extraction, chromatography on QAE-Sephadex A-25, salt precipitation, and hydrophobic chromatography on Phenyl-Sepharose 4B. The Beauveria bassiana lectin (BBL) is a 15 kDa glycoprotein rich in hydrophobic amino acids, without detectable amount of methionine. It contains 12.6% of carbohydrates including galactose and mannose. Isoelectric point was found at pH 7.1. The lectin is stable between pH 6 and 11, and at temperature under 50 degrees C. The activity of the lectin was not dependent on with Ca++, Mn++, Mg++ cations and was apparently not blood group ABO specific. The hemagglutination caused by the lectin was inhibited by alpha lactose (Gal beta 1-->4 Glc alpha), but not by beta lactose (Gal beta 1-->4 Glc beta). In direct ELISA the BBL preferentially reacted with some glycoproteins carrying O-linked sugar structure Gal beta 1-->3 GalNAc: strongly with human glycophorin A and weaker with mouse glycophorin, fetuin, IgA, ovine submaxillary mucin. On the other hand BBL did not react in direct ELISA with N-glycoproteins (alpha 1-acid glycoprotein, haptoglobin, fibronectin), however, N-glycoproteins could act as inhibitors of lectin-glycophorin A interaction. We observed also weak interaction with asialo-Tamm-Horsfall N-glycoprotein having unusual large, branched N-glycans with outer GalNAc beta 1-->4Gal sequence. Moreover, the interaction of BBL with highly sialylated preparations of glycoproteins was weaker than with asialo forms. Presented results indicate that BBL exhibits sugar binding specificity towards glycotope corresponding to Thomsen-Friedenreich antigen and its related sequences: Gal beta 1-->3 GalNAc > Neu Ac alpha 2-3 Gal beta 1-->3 (Neu Ac alpha 2-6) GalNAc > Gal beta 1-->4 Glc alpha.
Comp Biochem Physiol B Biochem Mol Biol 1999 May
PMID:Lectin from Beauveria bassiana mycelium recognizes Thomsen-Friedenreich antigen and related structures. 1042 10

Two recombinant human granulocyte colony-stimulating factor (rhG-CSF) isoforms were isolated from the medium conditioned by an engineered Chinese hamster ovary (CHO) cell line. The two rhG-CSFs were characterized and were found to differ in the carbohydrate structure attached to Thr-133. The glycoform, referred to as Peak 1, contains the O-linked glycan Neu5Ac(alpha 2-3)Gal(beta 1-3)GalNAc; the Peak 2 glycoform contains the O-linked glycan Neu5Ac(alpha 2-3)Gal(beta 1-3)[Neu5Ac(alpha 2-6)]GalNAc. The two glycoforms displayed a similar biological activity in cultures of a mouse 32D C13 cell line and human bone-marrow myelo-monocytic progenitor cells (CFU-GM). In the latter test both glycoforms displayed a higher activity than nonglycosylated rMet-hG-CSF from Escherichia coli. The pharmacokinetic profile and activity of the two rhG-CSF glycoforms and of a mixture of them (Pool) were investigated in mice treated with a single injection of rhG-CSF at the doses of 125 micrograms and 250 micrograms/kg, given via the intravenous (i.v.) and the subcutaneous (s.c.) route, respectively. The plasma concentration profiles obtained were similar for all three substances and did not show any relevant differences in absorption or elimination. The pharmacokinetic parameters indicate that the three substances have similar area under the curve (AUCs), volumes of distribution, and terminal half-life. Furthermore, our data indicate a high bioavailability of the two different glycoforms of rhG-CSF when given to mice via the s.c. route either singularly or as a mixture. Detectable levels of rhG-CSF persisted for more than 8 h in the i.v. and more than 24 h in the s.c. route of administration. All three substances induced early neutrophilia in mice. All rhG-CSF-treated mice developed a two-four-fold rise in neutrophil counts as early as 4 h after the intravenous and 2 h after the subcutaneous injection. Relatively high levels of neutrophils were maintained for at least 8 and 24 h after i.v. and s.c. administration, respectively.
Mol Biotechnol 1999 Apr
PMID:Purification and characterization of two recombinant human granulocyte colony-stimulating factor glycoforms. Pharmacokinetic and activity studies of single-dose administration in mice. 1046 66

The TEC-2 epitope is a carbohydrate located on the plasma membrane (oolemma) of the oocyte and appears to be involved in bovine sperm-oolemma fusion. The carbohydrates N-acetylgalactosamine (GalNAc) and galactose are part of the TEC-2 epitope and this study investigated the involvement of these carbohydrates during bovine fertilization. Gametes were exposed to the carbohydrates GalNAc, galactose, and fructose, and the lectins DBA and Con A to determine whether there was an effect on fertilization. The DBA lectin recognizes the carbohydrate GalNAc, whereas Con A recognizes the carbohydrates glucose and mannose. Oocytes pretreated with the DBA lectin prior to fertilization showed a reduction in cleavage corresponding to an increase in lectin concentrations. There was a significant increase in sperm-oolemma binding although fusion was inhibited. Oocytes exposed to GalNAc prior to sperm insemination had no effect on fertilization, however, sperm pretreatment with the carbohydrate caused inhibition of fertilization, with a reduction in cleavage rates as the GalNAc concentration increased. There was also a significant decrease in sperm-oolemma fusion and a significant increase in sperm-oolemma binding. When gametes were exposed to GalNAc at the time of fertilization a similar response to that seen with sperm pretreatment was observed. The carbohydrates galactose and fructose and the lectin Con A did not affect fertilization. In conclusion, the carbohydrate GalNAc, which is associated with the TEC-2 epitope, has a specific role during bovine sperm-oolemma fusion. This study also suggests that there is a carbohydrate-binding molecule on the sperm that binds GalNAc.
Mol Reprod Dev 1999 Oct
PMID:Inhibition of bovine sperm-oocyte fusion by the carbohydrate GalNAc. 1047 78

Giardia lamblia must encyst to survive in the environment and subsequently infect new hosts. We investigated the expression of glucosamine-6-phosphate isomerase (Gln6PI), the first enzyme required for biosynthesis of N-acetylgalactosamine, for the major cyst wall polysaccharide. We isolated two Gln6PI genes that encode proteins with large areas of identity, but distinctive central and terminal regions. Both recombinant enzymes have comparable kinetics. Interestingly, these genes have distinct patterns of expression. Gln6PI-A has a conventional, short 5' untranslated region (UTR), and is expressed at a low level during vegetative growth and encystation. The Gln6PI-B gene has two transcripts - one is expressed constitutively and the second species is highly upregulated during encystation. The non-regulated Gln6PI-B transcript has the longest 5'-UTR known for Giardia and is 5' capped or blocked. In contrast, the Gln6PI-B upregulated transcript has a short, non-capped 5'-UTR. A small promoter region (< 56 bp upstream from the start codon) is sufficient for the regulated expression of Gln6PI-B. Gln6PI-B also has an antisense overlapping transcript that is expressed constitutively. A shorter antisense transcript is detected during encystation. This is the first report of a developmentally regulated promoter in Giardia, as well as evidence for a potential role of 5' RNA processing and antisense RNA in differential gene regulation.
Mol Microbiol 1999 Oct
PMID:Developmental gene regulation in Giardia lamblia: first evidence for an encystation-specific promoter and differential 5' mRNA processing. 1056 76

Glycosaminoglycans (GAGs) are a family of acidic heteropolysaccharides, including such molecules as chondroitin sulfate, dermatan sulfate, heparin and keratan sulfate. Cleavage of the O-glycosidic bond within GAGs can be accomplished by hydrolases as well as lyases, yielding disaccharide and oligosaccharide products. We have determined the crystal structure of chondroitinase B, a glycosaminoglycan lyase from Flavobacterium heparinum, as well as its complex with a dermatan sulfate disaccharide product, both at 1.7 A resolution. Chondroitinase B adopts the right-handed parallel beta-helix fold, found originally in pectate lyase and subsequently in several polysaccharide lyases and hydrolases. Sequence homology between chondroitinase B and a mannuronate lyase from Pseudomonas sp. suggests this protein also adopts the beta-helix fold. Binding of the disaccharide product occurs within a positively charged cleft formed by loops extending from the surface of the beta-helix. Amino acid residues responsible for recognition of the disaccharide, as well as potential catalytic residues, have been identified. Two arginine residues, Arg318 and Arg364, are found to interact with the sulfate group attached to O-4 of N-acetylgalactosamine. Cleavage of dermatan sulfate likely occurs at the reducing end of the disaccharide, with Glu333 possibly acting as the general base.
J Mol Biol 1999 Dec 17
PMID:Crystal structure of chondroitinase B from Flavobacterium heparinum and its complex with a disaccharide product at 1.7 A resolution. 1060 Mar 83

In the present study, we characterized the post-translational modifications of a short-chain variant of mouse IgG2a that lacks the entire CH 1 domain. The short-chain IgG2a and its proteolytic fragments were subjected to electrospray ionization- and fast atom bombardment-mass spectrometric analyses. It has been demonstrated that approximately 14% of the heavy chain of the short-chain IgG2a is O-glycosylated with a disaccharide of Ga1-GalNAc- at Thr220A in the hinge region. while the Oglycosylation does not occur in its parent IgG2a molecule. Two additional modifications have been detected at the C-termini of both the heavy and light chains of the short-chain IgG2a. Biological significance of the post-translational modifications of the short-chain IgG2a variant is briefly discussed.
Mol Immunol
PMID:Post-translational modifications of immunoglobulin G: a mouse IgG variant that lacks the entire CH1 domain. 1069 3

MUC1 is a mucin-like type 1 transmembrane protein associated with the apical surface of epithelial cells. In human tumors of epithelial origin MUC1 is overexpressed in an underglycosylated form with truncated O-glycans and accumulates in intracellular compartments. To understand the basis for this altered subcellular localization, we compared the synthesis and trafficking of various glycosylated forms of MUC1 in normal (Chinese hamster ovary) cells and glycosylation-defective (ldlD) cells that lack the epimerase to make UDP-Gal/GalNAc from UDP-Glc/GlcNAc. Although the MUC1 synthesized in ldlD cells was rapidly degraded, addition of GalNAc alone to the culture media resulted in stabilization and near normal surface expression of MUC1 with truncated but sialylated O-glycans. Interestingly, the initial rate of endocytosis of this underglycosylated MUC1 was stimulated by twofold compared with fully glycosylated MUC1. However, the half-lives of the two forms were not different, indicating that trafficking to lysosomes was not affected. Both the normal and stimulated internalization of MUC1 could be blocked by hypertonic media, a hallmark of clathrin-mediated endocytosis. MUC1 endocytosis was also blocked by expression of a dominant-negative mutant of dynamin-1 (K44A), and MUC1 was observed in both clathrin-coated pits and vesicles by immunoelectron microscopy of ultrathin cryosections. Our data suggest that the subcellular redistribution of MUC1 in tumor cells could be a direct result of altered endocytic trafficking induced by its aberrant glycosylation; potential models are discussed. These results also implicate a new role for O-glycans on mucin-like membrane proteins entering the endocytic pathway through clathrin-coated pits.
Mol Biol Cell 2000 Mar
PMID:Clathrin-mediated endocytosis of MUC1 is modulated by its glycosylation state. 1071 2


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