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)

Isoelectric focusing was used to study the phenol oxidase isozymes in adult female worms of Schistosoma japonicum. More than one form of phenol oxidase has been demonstrated in extracts of female worms when incubated with 3,4-dihydroxyphenylalanine (DOPA), catechol or cresol as substrates. DOPA is the best substrate among all of them. The 5-6 bands of phenol oxidase exhibit pI values in the range of 6.0-7.5, the major band is at pI 6.0.
Mol Biochem Parasitol 1986 Jan
PMID:Isoenzymes of phenol oxidase in adult female Schistosoma japonicum. 308 53

We have identified and sequenced a cDNA clone of a mRNA found only in mature female schistosomes. This mRNA is not detectably synthesized by female worms from single sex infections (unisexual females), by males or by the developing miracidia in the eggs. The clone hybridises to a highly abundant polyadenylated mRNA of approximately 1500 nucleotides. The nucleotide sequence of the clone predicts a polypeptide comprising two repetitive regions. A pentapeptide repeat with the consensus sequence Gly-Tyr-Asp-Lys-Tyr, and a region rich in histidine residues. Hybrid selected mRNA translated in vitro with [3H]tyrosine as labelled amino acid yields a polypeptide of 48 kDa (p48) that corresponds to the major [3H]tyrosine labelled translation product of female worm total mRNA. p48 does not label with [35S]methionine and is absent from the translation products of male and unisexual female mRNAs. The amino acid sequence of p48 has significant homologies to silk moth chorion proteins and we suggest that it is one of the major components of the schistosome eggshell probably accounting for the high level of [3H]tyrosine incorporation into the vitellaria of Schistosoma mansoni. The tyrosine content of the polypeptide suggests that it may play a role in phenol oxidase mediated cross-linking of the schistosome eggshell and in support of this we find that mushroom phenol oxidase will cause the specific cross-linking of p48 in in vitro translation products.
Mol Biochem Parasitol 1987 Jan 02
PMID:Possible eggshell protein gene from Schistosoma mansoni. 310 Sep 49

Triton X-114 has been employed to isolate integral membrane proteins from Schistosoma japonicum and Schistosoma mansoni adult worms. Suitable marker molecules and antisera directed or raised against schistosome proteins partitioned by Triton X-114 extraction indicated that the phase separation and purification of integral membrane proteins had been successful and this fraction was free of contamination with aqueous (soluble) or secretory antigens. Two dimensional immunoblots further exemplified differences between antigens in the integral membrane protein extract and those of the aqueous fraction. Seven S. japonicum integral membrane proteins have been identified on immunoblots by serum from a hyperimmune and an infected rabbit and by sera from Philippine patients with a history of schistosomiasis japonica. Integral membrane proteins of S. mansoni and S. japonicum had surprisingly little conformity in the molecular weights and electrophoretic mobilities between the two species.
Mol Biochem Parasitol 1988 May
PMID:Immunoblotting analysis of the major integral membrane protein antigens of Schistosoma japonicum. 313 62

Adult Schistosoma mansoni of the hycanthone-sensitive and of the hycanthone-resistant strain were exposed in vitro to tritium-labeled hycanthone. The drug was taken up in similar amounts by the two strains, a result which is not compatible with hypothetical mechanisms of resistance based on reduced drug entry into the schistosomes. Labeled hycanthone was found to bind irreversibly to macromolecules of sensitive schistosomes, whereas the binding was minimal in resistant worms. In particular, the DNA of sensitive schistosomes showed high levels of tightly bound hycanthone, while the corresponding fraction of resistant schistosomes failed to do so. Female schistosomes and immature worms, which are less sensitive to hycanthone, showed a diminished drug-DNA binding with respect to adult males. Tritiated hycanthone N-methylcarbamate, which is effective against sensitive and resistant schistosomes, bound in similar amounts to the DNA of both strains. These results strongly support a previously proposed mechanism of action of hycanthone, which is based essentially on the alkylation of worm macromolecules by a drug derivative produced in sensitive schistosomes.
Mol Biochem Parasitol 1988 Oct
PMID:Binding of tritiated hycanthone and hycanthone N-methylcarbamate to macromolecules of drug-sensitive and drug-resistant schistosomes. 318 15

Detergent solubilized extracts of 125Iodogen surface labelled adult Loa loa revealed a relatively simple profile consisting of a strongly labelled molecule at 29-31 kDa and weakly labelled molecules at 14.5, 17, 21, 23, 34, 58, and 86 kDa. Residents of a L. loa endemic zone were assessed clinically and parasitologically and classified as microfilaremic, amicrofilaremic with documented ocular passage of adult worms, or 'resistant' subjects without any signs of infection. Sera from these subjects were used to identify L. loa adult surface antigens. All 'resistant' sera immunoprecipitated the 29-31 kDa antigen although some were more strongly reactive than others. The amicrofilaremic sera strongly immunoprecipitated the 29-31 kDa antigen, whereas microfilaremic sera reacted weakly or not at all with this antigen. Longer exposures of immunoprecipitates of strongly reactive sera revealed the recognition of additional antigens of 86, 44, 34, 23, 21, 17 and 14.5 kDa. Studies with heterologous sera demonstrated that these antigens contain cross-reactive epitopes which are restricted to filarial parasites. Biochemical characterization of the predominant 29-31 kDa antigen showed that it bound concanavalin A, was sensitive to proteases, and its antigenicity was resistant to heat but sensitive to periodate and endo-beta-N-acetylglucosaminidase H. These observations suggest that it is a glycoprotein containing mannose and N-acetylglucosamine residues and that the carbohydrate moiety is important for antibody binding. The importance of the 29-31 kDa glycoprotein in the immunobiology of loaiasis is suggested by the finding that resistant and infected amicrofilaremic individuals have strongly reactive IgG antibodies to this antigen.
Mol Biochem Parasitol 1988 Dec
PMID:The identification and partial characterization of an immunodominant 29-31 kilodalton surface antigen expressed by adult worms of the human filaria Loa loa. 322 11

We have shown the expression of transformed genes in the nematode Caenorhabditis elegans using a new gene fusion system. Vectors consisting of the flanking regions of a collagen gene (col-1) or a major sperm protein gene of C. elegans fused to the Escherichia coli uidA gene, encoding beta-glucuronidase, were microinjected into worms and found to be propagated as high-copy extrachromosomal tandem arrays. We have detected beta-glucuronidase activity in transformed lines, and have shown that the activity is dependent upon the correct reading frame of the construction and on the presence of the worm sequences. The enzyme activity was shown to be encoded by the chimeric beta-glucuronidase gene by co-segregation analysis and by inactivation with specific antisera. Expression is at a very low level, and seems to be constitutive. We have used histochemical techniques to visualize the enzyme activity in embryos.
J Mol Biol 1987 Jan 05
PMID:Expression of chimeric genes in Caenorhabditis elegans. 329 56

The major surface antigen (30 kDa) of Brugia pahangi has been characterised by a number of biochemical and immunochemical means. The 30 kDa polypeptide is a glycoprotein which can be extracted from the worm surface by homogenization in the absence of detergents. The 30 kDa polypeptide can be metabolically labelled with [35S]methionine in adult male and female parasites. In addition small amounts of the 35S-labelled 30 kDa antigen can be detected in the medium of worms cultured in vitro. 125I labelling of the excretory-secretory (ES) products of adult male and female parasites followed by immunoprecipitation and peptide mapping has confirmed the relationship between the surface located 30 kDa polypeptide and that released in vitro.
Mol Biochem Parasitol 1988 Jan 01
PMID:The biochemical and immunochemical characterisation of the 30 kilodalton surface antigen of Brugia pahangi. 334

The uptake of a diverse set of 14C-labelled non-electrolytes by Brugia pahangi and Dipetalonema viteae was measured relative to the free diffusion of tritiated water. Inulin was used as a non-absorbable surface marker to account for non-electrolyte adherent to the surface of the parasite which had not crossed the cuticle. B. pahangi and D. viteae took up the non-electrolytes to a similar degree; a comparison of tissue uptake indices gave a correlation coefficient of 0.99. Worm uptake could not be described by non-electrolyte octanol/aqueous partition coefficients alone. However, greater success was achieved using further descriptors and pattern recognition techniques for data analysis. The whole molecule descriptors log P, molar refraction, melting point, dipole moment and CNDO total energy were obtained from computer chemistry and the literature. Using a linear learning machine to relate uptake to these 5 physicochemical descriptors it was possible to successfully classify non-electrolytes as high or low uptake. Multivariate regression analysis of uptake versus these 5 parameters gave a correlation coefficient of 0.77. However, this was not statistically significant and therefore could not be used for quantitative predictions of substance uptake by worms. This illustrates the value of 'pattern recognition' techniques such as the linear learning machine. Using such 'pattern recognition' methods on a chemically related set of compounds it is anticipated that predictions of uptake can be achieved and improved upon. Such predictions could then be used in drug design.
Mol Biochem Parasitol 1988 Jan 15
PMID:Physicochemical characteristics of non-electrolytes and their uptake by Brugia pahangi and Dipetalonema viteae. 334 2

This report describes the structures of the high-mannose-type N-linked oligosaccharides in glycoproteins synthesized by Schistosoma mansoni adult male worms. Adult male schistosomes were incubated in vitro in media containing either [2-3H]mannose, [6-3H]glucosamine or [6-3H]galactose to allow metabolic radiolabeling of the oligosaccharide moieties of newly synthesized glycoproteins. Glycopeptides were prepared from the radiolabeled glycoproteins by digestion with Pronase and fractionation by chromatography on concanavalin A-Sepharose. Eleven percent of [3H]mannose incorporated into the schistosome glycopeptides was recovered in high mannose-type Asn-linked oligosaccharides which bound to the immobilized lectin. Upon treatment of [3H]mannose-labeled glycopeptide with endo-beta-N-acetylglucosaminidase H, the high mannose-type chains were released and their structures were determined by high performance liquid chromatography, methylation analysis, acetolysis and exoglycosidase digestion. The major species of high mannose-type chains synthesized by S. mansoni adult males have the composition Man7GlcNAc2, Man8GlcNac2 and Man9GlcNA2. Structural analyses indicate that these oligosaccharides are similar to high mannose-type chains synthesized by mammalian cells.
Mol Biochem Parasitol 1988 Apr
PMID:Characterization of the high mannose asparagine-linked oligosaccharides synthesized by Schistosoma mansoni adult male worms. 338 83

Chitinase activity has been detected in female worms of Onchocerca gibsoni. With 3,4-dinitrophenyl-tetra-N-acetylchitotetraoside as substrate 50% of maximum activity was achieved at about 25 microM substrate, with inhibition above 50 microM substrate. The antibiotic allosamidin very strongly inhibited the chitinase activity, 50% inhibition being achieved by 200 pM allosamidin in the presence of 45 microM substrate.
Mol Biochem Parasitol 1988 Jun
PMID:Chitinase in female Onchocerca gibsoni and its inhibition by allosamidin. 341 76


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