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Query: UNIPROT:P06889 (Mol)
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A cDNA library representative of adult Schistosoma mansoni mRNA populations was screened with serum from infected rats (refractory hosts), positive plaques being rescreened with serum from infected mice and humans. Based on general reactivity, one clone was selected for further study. As judged by immunofluorescence data, size of corresponding mRNA, and nucleotide sequence analysis, the recombinant expresses approximately 625 amino acids of a schistosome muscle myosin rod. Antibodies evoked by the protein do not cross-react with human cardiac or skeletal muscle, are not invariably stimulated in naturally infected human beings, and rise in titer after chemotherapeutic cure, findings which suggest that the antigen is not a causative agent of Katayama fever, and is probably presented by degenerating worms. The schistosome sarcomeric myosin gene, the most primitive examined to date, appears to be unique inasmuch as it may not be a member of a multigene family and encodes a single mRNA transcript; nonetheless, predicted higher order structure of its translation product is consistent with expected function.
Mol Biochem Parasitol 1987 Nov
PMID:Molecular cloning of Schistosoma mansoni myosin. 343 65

A cloned library of DNA complementary to the mRNA of adult Schistosoma japonicum has been prepared and expressed as fusion proteins with Escherichia coli beta-galactosidase. Colonies expressing the S. japonicum cDNA clones were screened both with antibodies from individuals with a history of schistosomiasis and with antibodies obtained from a rabbit immunized with whole adult worms. In both cases colonies were detected which bound antibody, although the frequency of antigen-positive clones was much higher with the rabbit antiserum than with human sera. In both cases the proportion of colonies reacting with antibodies was markedly lower than that published for equivalent screens of Plasmodium falciparum cDNA with sera from individuals with a history of falciparum malaria. Several major S. japonicum antigens were identified by the affinity purification of antibodies using immobilised fusion proteins produced during lytic growth of the recombinant bacteriophage.
Mol Biochem Parasitol 1986 Mar
PMID:Expression of Schistosoma japonicum antigens in Escherichia coli. 351 79

The lipid compositions of mature male and female Schistosoma mansoni and cercariae were compared to that of the hepato-pancreas of unparasitised Biomphalaria globrata (the intermediate snail host), and of red blood cells and sera of hamsters (the mammalian host). Membranes were isolated from the tegument of mature schistosomes by spontaneous release into phosphate-buffered saline, with or without vortexing, and by removal from the parasite's surface using poly-lysine beads. The phospholipid composition of the membranes prepared by the three methods showed a typical plasma membrane-like profile, with high sphingomyelin content (approximately 20%) and cholesterol to phospholipid molar ratio (0.7-1.1). The fatty acid compositions of the resolved phospholipid classes were analysed. Although the composition was in general unremarkable, a high content of eicosaenoic acid (20:1), rarely found in mammals, was noted in whole schistosomes, cercariae, the hepato-pancreas of unparasitised Biomphalaria, and the isolated tegumental membranes. Eicosaenoic acid was also found in adults of Schistosoma japonicum. Host serum lipids from normal and parasitised hamsters contained extremely low amounts of eicosaenoic acid, indicating that this fatty acid is probably continually synthesised by the parasite, probably from preformed fatty acid precursors provided by the host.
Mol Biochem Parasitol 1987 Mar
PMID:The phospholipid and fatty acid composition of Schistosoma mansoni and of its purified tegumental membranes. 357 54

Short-term in vitro pulse-labeling of the free glucose pool in pairs of Schistosoma mansoni, and measurement of the increase in [14C]glucose in the female partner (and the concomitant decrease in the male), has established that glucose can be transferred from male to female schistosomes. It is demonstrated that this transfer is not inhibited by ouabain in S. mansoni. Free glucose levels have been measured in Schistosoma haematobium, Schistosoma japonicum and S. mansoni. Data indicate that the transfer of glucose is not via an active mechanism, but rather the transfer of glucose occurs along a glucose concentration gradient which exists between males and females.
Mol Biochem Parasitol 1985 Nov
PMID:The mechanism and rate of glucose transfer from male to female schistosomes. 406 56

The niaD and niiA genes of Aspergillus nidulans, which code, respectively, for nitrate and nitrite reductases, are divergently transcribed, and their ATGs are separated by 1,200 bp. The genes are under the control of the positively acting NirA transcription factor, which mediates nitrate induction. The DNA binding domain of NirA was expressed as a fusion protein with the glutathione S-transferase of Schistosoma japonicum. Gel shift and footprint experiments have shown that in the intergenic region there are four binding sites for the NirA transcription factor. These sites can be represented by the nonpalindromic consensus 5'CTCCGHGG3'. Making use of a bidirectional expression vector, we have analyzed the role of each of the sites in niaD and niiA expression. The sites were numbered from the niiA side. It appeared that site 1 is necessary for the inducibility of niiA only, while sites 2, 3, and to a lesser extent 4 (which is nearer to and strongly affects niaD) act bidirectionally. The results also suggest that of the 10 binding sites for the AreA protein, which mediates nitrogen metabolite repression, those which are centrally located are physiologically important. The insertion of an unrelated upstream activating sequence into the intergenic region strongly affected the expression of both genes, irrespective of the orientation in which the element was inserted.
Mol Cell Biol 1995 Oct
PMID:The intergenic region between the divergently transcribed niiA and niaD genes of Aspergillus nidulans contains multiple NirA binding sites which act bidirectionally. 756 20

A recombinant lambda gt11 clone, IVGS3, encoding part of a 55-kDa antigen was isolated from an adult Schistosoma japonicum cDNA library. The protein expressed by this clone was recognised strongly by serum from rats that had been vaccinated with irradiated cercariae (VrS) rendering them highly immune to a challenge infection. Antibodies in VrS which were specific for IVGS3 did not recognise adult worm antigens of S. mansoni, suggesting that the recombinant antigen contains species-specific epitopes, although IVGS3 was weakly recognised by rat serum raised against irradiated S. mansoni cercariae, indicating the presence of a related antigen in this species. A further clone, AM1(p), was obtained which, together with IVGS3 encompasses the entire coding region of the gene which has been called Sj55. Sequence analysis revealed similarities with murine calreticulin, a protein resident in the endoplasmic reticulum. As with murine calreticulin, Sj55 was shown to be a calcium-binding protein. Antigens with homologies to calreticulin have also been described in two other helminths, S. mansoni and Onchocerca volvulus.
Mol Biochem Parasitol 1995 Apr
PMID:Cloning of a Schistosoma japonicum gene encoding an antigen with homology to calreticulin. 763 Mar 85

This report presents the deduced amino acid sequence of a novel cathepsin L proteinase from Schistosoma mansoni, and describes cathepsin L-like activity in extracts of adult schistosomes. Using consensus primers specific for cysteine proteinases, gene fragments were amplified from adult S. mansoni cDNA by PCR and cloned. One of these fragments showed marked identity to Sm31, the cathepsin B cysteine proteinase of adult S. mansoni, whereas another differed from Sm31 and was employed as a probe to isolate two cDNAs from an adult S. mansoni gene library. Together these cDNAs encoded a novel preprocathepsin L of 319 amino acids; this zymogen is predicted to be processed in vivo into a mature, active cathepsin L proteinase of 215 amino acids. Closest homologies were with cathepsins L from rat, mouse, and chicken (46-47% identity). Southern hybridization analysis suggested that only one or a few copies of the gene was present per genome, demonstrated that its locus was distinct from that of Sm31, and that a homologous sequence was present in Schistosoma japonicum. Because these results indicated that schistosomes expressed a cathepsin L proteinase, extracts of adult S. mansoni were examined for acidic, cysteine proteinase activity. Based on rates of cleavage of peptidyl substrates employed to discriminate between classes of cysteine proteinases, namely cathepsin L (Z-phe-arg-AMC), cathepsin B (Z-arg-arg-AMC) and cathepsin H (Bz-arg-AMC), the extracts were found to contain vigorous cathepsin L-like activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Biochem Parasitol 1994 Sep
PMID:Adult Schistosoma mansoni express cathepsin L proteinase activity. 783 71

cDNA clones encoding a 28-kDa subunit glutathione S-transferase (GST) from Schistosoma mansoni (Sm28GST) and a 26-kDa subunit GST from Schistosoma japonicum (Sj26GST) have been expressed in bacterial systems. The recombinant proteins were purified to homogeneity by batch-wash glutathione-agarose affinity chromatography and their biochemical properties investigated. Gel filtration chromatography indicated that both recombinant GSTs are homodimeric proteins. Resolution of Sm28GST and Sj26GST by chromatofocusing in the ranges pH 9-6 and pH 7-4 gave pI estimates of 7.4 and 5.0, respectively. Kinetic analyses suggested that both Sm28GST and Sj26GST operate via a sequential bisubstrate catalytic mechanism. Sm28GST and Sj26GST displayed a mosaic of mammalian Alpha-, Mu- and Pi-type substrate specificities and inhibitor sensitivities. However, multivariate analysis suggests that Sm28GST has an overall catalytic homology with mammalian Mu class GSTs, whilst the enzymatic properties of Sj26GST appear to constitute a hybridisation of Mu and Alpha class features. Both recombinant GSTs interact with a range of hydrophobic ligands including haematin and related compounds, bile acids and several anthelmintics. Sm28GST and Sj26GST possess relatively limited selenium-independent glutathione peroxidase activities, but are able to catalyse the glutathione conjugation of members of the trans,trans-alka-2,4-dienal, trans-alk-2-enal and 4-hydroxyalk-2-enal series of reactive carbonyls (known secondary products of lipid peroxidation).
Mol Biochem Parasitol 1993 Oct
PMID:Biochemical properties of cloned glutathione S-transferases from Schistosoma mansoni and Schistosoma japonicum. 826 29

Statistical analysis of glutathione S-transferase (GST) sequences of Schistosoma mansoni, Schistosoma japonicum, and other animals revealed that, in comparison both to the related mammalian alpha GSTs and to Schistosoma 26-kDa GSTs, the 28-kDa GSTs of Schistosoma have evolved unusually rapidly at the amino acid level in the ordinarily conserved N-terminal portion of the molecule. Because this rapid rate of evolution is reflected at the amino acid level and at nonsynonymous nucleotide sites but not at synonymous nucleotide sites, it must be due to a relaxation of functional constraint on the N-terminal region of the Schistosoma 28-kDa GSTs rather than to a high mutation rate. By contrast, the 26-kDa GSTs of Schistosoma not only show a slower rate of amino acid evolution in the N-terminal portion than the 28-kDa GSTs but also have evolved more slowly in the C-terminal portion than have the related mammalian mu GSTs. The two 26-kDa GSTs of S. mansoni show particularly strong amino acid conservation between one another in the N-terminal region and a predominance of conservative amino acid replacements.
Mol Biochem Parasitol 1993 Mar
PMID:Rates of amino acid evolution in the 26- and 28-kDa glutathione S-transferases of Schistosoma. 845 35

The cuticle of parasitic nematodes is composed of extracellular structural proteins. Over 90% of these proteins are collagenous molecules in the basal and median layers of the cuticle. The outermost layers of the cuticle, the epicuticle, is composed of non-collagenous proteins, that represent the structural surface of nematodes. In Ascaris these proteins have been termed 'cuticlins'. While cuticular collagens have been well studied by both biochemical and genetic means, knowledge of the molecular structure of cuticlin components of parasitic nematodes is scarce. In the present paper we report on the production of monoclonal antibody 8.1, which is specific for cuticlin, but does not recognize collagen epitopes. We have screened a cDNA library derived from adult Ascaris suum mRNA of the hypodermal tissue underlying and synthesizing the cuticle. One positive cDNA clone encodes alanine-rich repetitive motifs, which are part of the insoluble cuticlin of the outermost layers of the epicuticle of Ascaris suum. This was shown in immunocytochemical experiments using specific polyclonal antisera raised against these motifs, expressed as fusion protein with glutathione S-transferase of the helminth Schistosoma japonicum. Comparison of the repetitive amino acid sequence with structural proteins of the nematode Caenorhabditis elegans and the insects Locusta migratoria and Ceratitis capitata revealed a minimal consensus motif.
Mol Biochem Parasitol 1996 Sep
PMID:Repetitive peptide motifs in the cuticlin of Ascaris suum. 888 22


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