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)

Metabolic radiolabeling of adult worms of Schistosoma mansoni with [3H]myristic acid has revealed that the fatty acid is incorporated into more than 15 proteins. We have shown that two of these proteins, a 200-kDa glycoprotein known to be exposed on the surface of the adult worm following praziquantel treatment and a 22-kDa glycoprotein that shows an enhanced immune reactivity with sera of vaccinated mice, are anchored to the adult worm membrane via a glycosylphosphatidylinositol (GPI) linkage. Both antigens partitioned preferentially into the detergent phase of Triton X-114 and were susceptible, following immunoaffinity purification, to hydrolysis by phosphatidylinositol-specific phospholipase C (PIPLC) from Bacillus thuringiensis and phospholipase C from Bacillus cereus. Diacylglycerol (DAG) was released following hydrolysis by bacterial PIPLC; however, Trypanosoma brucei GPIPLC failed to release the diacylglycerol from either protein. Treatment with nitrous acid generated phosphatidylinositol (PI) from both proteins, and phospholipase D from rat serum cleaved phosphatidic acid from the 200-kDa protein. Although the functional significance of these GPI-anchored proteins is unknown, their release from the surface of the schistosome may contribute to immune evasion.
Mol Biochem Parasitol 1990 Jan 15
PMID:Identification and characterization of glycosylphosphatidylinositol-linked Schistosoma mansoni adult worm immunogens. 213 72

This study describes the production and characterization of a monoclonal antibody (mAb) against the alkaline phosphatase of Schistosoma mansoni from splenocytes of chronically infected mice. Convenient selection of the mAb was achieved using the catalytic activity of the antigen in a developed enzyme-antigen immunoassay. The mAb was of the IgG1 subclass and it specifically recognized the alkaline phosphatase in adult worm sections by indirect immunofluorescence. Preincubation of the antibody with partially purified adult alkaline phosphatase did not result in inhibition of the enzyme activity and it did not mediate complement-dependent cytotoxicity against mechanically transformed schistosomula in vitro. The mAb was able to immunoprecipitate under reducing conditions a polypeptide of 65 kDa, similar in size to the monomeric subunit of the schistosome enzyme. The specificity of the mAb was assessed by competitive inhibition with antibodies of infected human sera in an immunoadsorption assay. Periodate treatment of the antigen resulted in altered electrophoretic mobility of alkaline phosphatase, which confirmed the presence of carbohydrate in the molecule, but this did not prevent binding by the mAb. Although the use of the mAb in capture assays for detection of circulating alkaline phosphatase in infected host sera was unsuccessful, the production of this antibody confirmed that the enzyme is exposed by adult worms to the host and that it is immunogenic; additionally, a monoclonal probe is available for further characterization of the structure and function of this important parasite surface molecule.
Mol Biochem Parasitol 1990 Apr
PMID:Production of a mouse monoclonal antibody against the alkaline phosphatase of adult Schistosoma mansoni. 216 96

A 43-kDa putative lipoprotein receptor from Schistosoma japonicum adult worms (Sj43) has been purified by reverse-phase high-performance liquid chromatography (HPLC) using a Waters Delta-pak C4 300 A 15 mu 3.9 mm x 300 mm column. A linear acetonitrile gradient from 10-95%, spanning 40 min and at a flow rate of 0.9 ml min-1 was employed for the elution of bound material. Sj43 had a retention time of approximately 13 min on the column, whereas other main components from the parasite extract had a much longer retention time. Sj43 purified as a doublet which could be cleaved with Staphylococcus aureus V8 protease but was unaffected by treatment with a mixture of endoglycosidase F and glycopeptidase F. Human low-density lipoprotein exhibited typical saturation kinetics on the HPLC-purified Sj43 with a calculated stoichiometry of 2 mol LDL mol-1 of the putative receptor. No evidence of high-density lipoprotein (HDL3) saturation was observed on purified Sj43, this being of some interest since it parallels observations made with mammalian HDL3-binding proteins.
Mol Biochem Parasitol 1990 Jun
PMID:Purification of a putative lipoprotein receptor from Schistosoma japonicum adult worms. 216 13

Cadmium speciation of the intestinal compartment of the earthworm species, Lumbricus terrestris, has been investigated using polyacrylamide gel electrophoresis under non-denaturing conditions. Worms exposed to Cd(NO3)2 supplemented soils have been studied and compared to control samples. Prior to electrophoresis, the worm intestines were removed and dissected. Proteins in the crude intestinal extracts were separated using polyacrylamide gel electrophoresis. The cadmium distribution in the proteins has also been described. In a second set of experiments, cadmium bound to proteins was first isotopically exchanged with labelled cadmium (109Cd) and then cadmium speciation was performed using gel electrophoresis. Autoradiography of this gel shows an intense band in the contaminated sample whereas this band was absent in the control sample. These results show that one type of major protein has a strong affinity for cadmium in the worm intestinal extract. This type of protein had a migration close of that of rabbit liver metallothionein used for comparison.
Mol Cell Biochem 1990 Sep 21
PMID:Cadmium speciation studies in the intestine of Lumbricus terrestris by electrophoresis of metal proteins complexes. 228 Jul 62

It was previously shown that an antigen preparation termed 9B obtained from Schistosoma mansoni cercarial extracts partially (34%) protects mice from challenge infection with cercariae (R. Tarrab-Hazdai et al., J. Immunol. 135, 2772, 1985). To characterize some of the proteins which comprise this preparation, rabbit antibodies to the 9B antigen preparation were used to screen cDNA libraries of cercariae and adult worms. We isolated and sequenced cDNA clones encoding three proteins: calcium-binding protein, paramyosin, and myosin. The calcium-binding protein was previously shown to be expressed in cercariae but not in sporocysts or adult worms (D. Ram et al., Mol. Biochem. Parasitol. 34, 167, 1989). Northern blots showed the presence of paramyosin and myosin mRNAs in sporocysts and adult worms but not in cercariae. Antibodies to paramyosin detected the protein in sporocysts and adult worms as well as in cercariae. These findings explain, in part, the protective activity of the 9B antigen preparation against challenge infection.
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PMID:Schistosoma mansoni: stage-specific expression of muscle-specific genes. 229 27

A cDNA clone encoding part of a 20-kDa antigen of Schistosoma mansoni (Sm20) has been isolated. The amino acid sequence of this antigen, as predicted from the sequence of the cDNA, has significant homology to the family of calcium binding proteins which include calmodulin, troponin C and the light chain of myosin. Although we have been unable to show any immunological cross-reactivity between Sm20 and calmodulins from a range of other species, we have verified that Sm20 is a functional calcium binding protein. Sm20 is encoded by a small multigene family and is expressed in schistosomula and adult worms but not in eggs. The 20-kDa nascent polypeptide appears to be post-translationally modified to give a 38-kDa species. Sm20 is present in preparations of tegumental membranes and is easily removed from intact schistosomula by detergent treatment, suggesting that it is associated with the tegument. However, the cloned portion does not appear to be exposed on the surface.
Mol Biochem Parasitol 1990 Jan 15
PMID:Characterisation of Sm20, a 20-kilodalton calcium-binding protein of Schistosoma mansoni. 232 6

We have cloned cDNAs encoding a 35-kilodalton cysteine protease that is a major component of protective extracts isolated from blood-feeding Haemonchus contortus adult worms. Near full-length cDNAs for the protease were isolated by immunoscreening an adult worm cDNA expression library with a rabbit antiserum prepared against the protein eluted from preparative SDS gels and by rescreening the library with oligonucleotide probes. The protein predicted from the nucleotide sequence of the cDNAs and of a genomic DNA clone comprises 342 amino acids and contains an N-terminal signal sequence, 16 cysteine residues and four potential N-linked glycosylation sites. The enzyme appears to be glycosylated in vivo. The H. contortus protease, called AC-1, displays an overall 42% sequence identity with the human lysosomal thiol protease cathepsin B. The similarities between cathepsin B and AC-1 are localized primarily to regions of cathepsin B that comprise the mature, active form of the enzyme. A stretch of six amino acids that includes the active site cysteine of cathepsin B is conserved, and is present in the same relative location in AC-1, suggesting that this region comprises the active site of the H. contortus enzyme.
Mol Biochem Parasitol 1990 Jun
PMID:Molecular cloning and primary sequence of a cysteine protease expressed by Haemonchus contortus adult worms. 238 65

A Schistosoma mansoni cDNA library was constructed from the mRNA of adult worms in the expression vector lambda gt11 and screened with a rabbit antiserum raised against the 26-kDa S. mansoni glutathione S-transferase isoforms (Sm GST 26). Two clones were selected and the nucleotide sequences deduced. The predicted amino acid sequence, specified by these cDNAs, shows strong homology with a Schistosoma japonicum 26 kDa glutathione S-transferase and a lower level of homology with mammalian glutathione S-transferase class mu isoenzymes (EC 2.5.1.18). No significant homology score was found with a 28-kDa S. mansoni glutathione S-transferase (Sm GST 28). A study of the tissue distribution of the cloned Sm GST 26 by immunoelectron microscopy shows similarities to Sm GST 28 in that they are present in the tegument and in subtegumentary parenchymal cells. However, a major difference exists in the protonephridial region in which Sm GST 26 is present in the cytoplasmic digitations localized in the apical chamber delineated by the flame cell body, suggesting that Sm GST 26 may be actively excreted by adult worms.
Mol Biochem Parasitol 1990 Jun
PMID:Molecular cloning and tissue distribution of a 26-kilodalton Schistosoma mansoni glutathione S-transferase. 238 66

Two clones which contain genes encoding Schistosoma mansoni proteins recognized by immune mouse sera were chosen from cDNA lambda gt11 expression vector library by preselecting clones from the library with rabbit antisera against adult worm phosphate-buffered saline (PBS)-soluble antigens. One clone, MAC 182, codes for part of a Mr 70 000 protein; the other clone, MAC 184, codes for a Mr 27 000 protein. The insert sizes of MAC 182 and MAC 184 are 400 bp and 800 bp, respectively. Both clones express S. mansoni beta-galactosidase fusion proteins as products of the construct. Antibodies from either chronically infected mice or mice vaccinated with irradiated cercariae recognize the MAC 182 fusion protein (MAC 182fp) but not the MAC 184 fusion protein (MAC 184fp). Rabbit antibodies prepared against MAC 182fp immunoprecipitate a Mr 70 000 in vitro translation product from adult mRNA and react in Western blot with a corresponding Mr 70 000 protein present in eggs, cercariae and adult worms but absent in schistosomula. Although the MAC 184fp is not recognized directly by chronic infection or vaccinated mouse antibodies, antisera prepared against the purified fusion protein immunoprecipitate a Mr 27 000 in vitro translation product which also reacts with mouse chronic infection sera. The same Mr 27 000 protein appears to be present in eggs, cercariae, schistosomula and adults as determined by Western blots with rabbit antisera against the MAC 184fp. These results suggest that the S. mansoni polypeptide encoded by the MAC 184 gene, when expressed within a fusion protein, fails to present epitopes normally recognized during natural infection. We propose that these epitopes are conformationally determined and are destroyed when the MAC 184 protein is expressed within beta-galactosidase. This abrogation of conformational epitopes may explain the failure of antibodies from chronically infected or vaccinated mice and rabbits to effectively recognize gene products of certain lambda gt11-fusion protein clones.
Mol Biochem Parasitol 1985 Oct
PMID:Expression in Escherichia coli of two Schistosoma mansoni genes that encode major antigens recognized by immune mice. 241 57

A range of excretory-secretory (ES) antigens have been characterised following in vitro culture of adult Brugia pahangi filarial nematodes in serum-free medium. Analysis by radioiodination, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and immunoprecipitation of purified macromolecules with antibodies from human and experimental animal infections reveals both host and parasite components. Two host molecules appear by molecular weight and immunoprecipitation analysis to be immunoglobulin and serum albumin, presumed to be taken up from the jird host from which adult worms were recovered. A further prominent component, of 19 kDa, reacts with neither anti-host nor anti-filarial antibodies, and may represent a non-immunogenic parasite product. Three additional bands, although less intensely radiolabelled, did prove to be consistently antigenic, with apparent molecular weights of 15, 29 and 40 kDa. A further ES antigen, which does not take up radio-iodine or lend itself to electrophoretic analysis, has also been detected. This molecule reacts in a immunoradiometric assay in which monoclonal antibody directed against a repetitive epitope acts both to capture and indicate antigen presence. The same antibody, Bp-1, may also be employed to detect circulating antigen in the serum of animals experimentally infected with Brugia pahangi, and in the serum of patients with each of the three species of human lymphatic filariasis, Brugia malayi, Brugia timori and Wuchereria bancrofti.
Mol Biochem Parasitol 1985 Dec
PMID:Secreted and circulating antigens of the filarial parasite Brugia pahangi: analysis of in vitro released components and detection of parasite products in vivo. 241 15


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