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

The Onchocerca volvulus superoxide dismutase was expressed in Escherichia coli, using a protocol designed to produce the native enzyme rather than a fusion protein. The recombinant O. volvulus superoxide dismutase (rOVSOD) was found in the cytosol of the disrupted bacteria and represented > 10% of the total bacterial protein. The enzyme was purified to homogeneity using DEAE-Sepharose chromatography, followed by phenyl-Sepharose chromatography. The rOVSOD was enzymatically active which was demonstrated by its reactivity with O2.- produced either by the xanthine-xanthine oxidase system or by stimulated eosinophils. The specific activity was determined to be 4668 U mg-1. This activity could be blocked by rabbit antiserum raised against the rOVSOD. The maximal activity was obtained upon supplementation of the bacterial growth media and enzyme buffer with copper and zinc ions. Activity characteristics in the presence of inhibitors was also characteristic of a Cu/Zn superoxide dismutase. The rOVSOD has an apparent subunit molecular mass of 16,000 in SDS-PAGE. The active enzyme behaves as a dimer of 32 kDa as determined by gel filtration.
Mol Biochem Parasitol 1994 Sep
PMID:Characterization of enzymatically active Onchocerca volvulus Cu/Zn superoxide dismutase expressed in Escherichia coli. 783 82

Protein disulfide isomerase (PDI) functions to catalyze the formation of correct disulfide bonds in nascent proteins, and also acts as one of the subunits of prolyl-4 hydroxylase, the enzyme responsible for the oxidative maturation of procollagen. Since the cuticle of parasitic nematodes consists primarily of a network of collagen molecules which are connected through intermolecular disulfide bonds, PDI might be expected to be involved in the process of cuticle biosynthesis. The isolation and characterization of a cDNA encoding the PDI homologue of Onchocerca volvulus is described. This cDNA contains a single, long open reading frame that encodes sequence motifs identical to the two known active sites of PDI for isomerase activity. The O. volvulus PDI appears to be encoded by a single copy gene. Both in situ hybridization and immunolocalization data suggest that PDI is both spatially and temporally regulated in O. volvulus. The pattern of spatial and temporal regulation is consistent with the involvement of PDI in the biosynthesis of the parasite cuticle. The parasite protein appears to be an antigen recognized by a minority of individuals exposed to O. volvulus.
Mol Biochem Parasitol 1994 Nov
PMID:The Onchocerca volvulus homologue of the multifunctional polypeptide protein disulfide isomerase. 789 35

Immunological crossreactivity among nematodes has hampered development of specific serodiagnostic assays for lymphatic filariasis. In the present study, we report the molecular cloning and characterization of two filaria-specific recombinant clones (BmM5 and BmM14) with immunodiagnostic potential. BmM5 is a 505-bp cDNA which codes for a protein of 130 residues that ends with an endoplasmic reticulum targeting sequence. BmM14 is closely related to a recently reported clone (SXP-1), and it has 62% homology (deduced amino acid sequence) with a previously described Onchocerca volvulus clone, lambda RAL-2. Glutathione S-transferase fusion proteins of BmM5 and BmM14 were tested in various ELISA formats. The best results were obtained by measuring IgG4 antibodies to the fusion proteins. ELISA studies showed that approximately 90% of 111 sera from Indian and Egyptian patients with brugian and bancroftian filariasis were reactive with both antigens. Nonendemic sera as well as sera from patients with schistosomiasis or intestinal helminths were uniformly nonreactive. Assays based on BmM5 and BmM14 may be useful for large scale screening as an alternative to microfilaria or filarial antigen detection as a means of obtaining a rough index of filariasis endemicity in previously unstudied areas.
Mol Biochem Parasitol 1994 Apr
PMID:Molecular cloning of Brugia malayi antigens for diagnosis of lymphatic filariasis. 793 4

The identification and characterization of a recombinant cDNA clone, designated OV9M, expressing an antigen present in Onchocerca volvulus infective larvae and adult stages is described. Clone OV9M was identified by screening a lambda gt11 cDNA expression library derived from adult O. volvulus mRNA using pooled rabbit antisera raised against the third (L3) and fourth (L4) stage larvae of the parasite. The cDNA clone encodes an open reading frame of 238 amino acids corresponding to a 27-kDa polypeptide. This polypeptide contains a series of five highly conserved repeats of 25 amino acids that are similar to repeats found in calponin, a protein previously only identified in vertebrate smooth muscle. Extension of the 5' end of the cDNA clone revealed two additional repeats extending the sequence to 378 amino acids, encoding a 41.8-kDa protein. Affinity purified antibodies, which bound specifically to the glutathione S-transferase-OV9M fusion polypeptide, recognize a series of antigens in extracts of O.volvulus microfilariae, L3, L4 and adult stages. The apparent molecular weight of the native OV9M protein in the adult is 45 kDa. Similar proteins are present in extracts of other nematodes including Caenorhabditis elegans, and antibodies from other filarial infections are cross reactive with glutathione S-transferase-OV9M fusion polypeptide. Immunoelectron microscopy revealed that the antigen encoded by this clone is present in the longitudinal muscles of the various larval stages and adult worms. Antibodies to the OV9M protein are present in 40-60% of both patently infected and non-patent individuals residing in onchocerciasis endemic areas.
Mol Biochem Parasitol 1994 May
PMID:Identification and characterization of an Onchocerca volvulus cDNA clone encoding a highly immunogenic calponin-like protein. 793 20

The increased incidence of "allergic" symptomatology and clinical complications seen in non-endemic individuals with loiasis, as compared to natives of endemic areas, is thought to reflect a heightened immune response to filarial antigens. To identify antigens involved in this hyperresponsiveness, a cDNA library constructed from adult female RNA from the related filarial parasite, Onchocerca volvulus, was screened with serum from a North American who acquired loiasis in West Africa. Sequence analysis of one of the identified clones, OvGalBP, revealed significant homology to the vertebrate S-type lectins, a family of thiol-dependent, metal-independent galactoside binding lectins, which includes an IgE-binding protein thought to be involved in IgE regulation. The 1100-bp insert of OvGalBP contains the entire protein coding region and has a 3' poly(A) tail. The two amino acid consensus sequences (WGxExR and HFNPRF) found in all of the S-type lectins are present. Purified recombinant protein expressed as a fusion with glutathione-S-transferase (OvGalBP-GST) was recognized by sera from a majority of filaria-infected patients but not by putatively immune individuals from an endemic area or by unexposed endemic and non-endemic controls. Interestingly, OvGalBP-GST specifically bound IgE (and not IgG) in a lactose-inhibitable manner, suggesting a potential role for this protein in the pathophysiology of human filarial infection.
Mol Biochem Parasitol 1994 Jun
PMID:OvGalBP, a filarial antigen with homology to vertebrate galactoside-binding proteins. 796 71

Glutathione S-transferases (GSTs) constitute a major detoxification mechanism in helminth organisms and are regarded vaccine candidates against helminth infections. Onchocerca volvulus glutathione-binding proteins were purified from the aqueous soluble fraction of homogenised adult females by affinity chromatography on glutathione-agarose. The eluted proteins had a specific GST activity of 1.6 mumol min-1 mg-1. Immunohistochemical studies localised these antigens in the hypodermis, the wall of the seminal receptacle and spermatozoa of adult worms. A lambda gt11 clone was isolated from an expression library of O. volvulus by immunoscreening. Sequence analysis revealed that it encoded a pi-class GST with 60% identity with Caenorhabditis elegans and up to 45% identity with mammalian pi-class GSTs. Antibodies affinity selected with recombinant GST demonstrated cross-reactivity between Litomosoides sigmodontis and O. volvulus GSTs.
Mol Biochem Parasitol 1994 Jul
PMID:Molecular characterisation and localisation of an Onchocerca volvulus pi-class glutathione S-transferase. 798 70

A novel repetitive antigen from the cattle parasite Onchocerca gibsoni was shown to be recognised by sera from humans infected with Onchocerca volvulus, Wuchereria bancroftii or Brugia malayi. The O. gibsoni protein was produced in a recombinant form, and antibodies raised to this protein used to screen cDNA libraries for O. volvulus. A series of clones were isolated which encoded repetitive regions very similar to those in O. gibsoni, but interspersed between these were longer repeating units which we have not so far found in O. gibsoni. The repetitive antigen was shown to be of high molecular weight and present only in the insoluble (membrane) fraction of O. gibsoni microfilariae. Immunofluorescence techniques demonstrated that the antigen was associated both with muscle and with specific membrane layers, including a peripheral layer which corresponds to either the outer hypodermis or an inner region of the cuticle in adult female O. gibsoni. In many respects, the proteins encoded by the O. gibsoni and O. volvulus cDNA clones resembled repetitive antigens from several distantly related eukaryotic parasites, and a possible common role in immune evasion is discussed.
Mol Biochem Parasitol 1994 Jan
PMID:Identification and characterisation of a novel repetitive antigen from Onchocerca spp. 818 22

Repeated DNA sequences have been instrumental in the development of DNA probes for many different parasites. Isolation of such DNA probes has generally been accomplished by differential screening of genomic libraries with total genomic DNA preparations. In the current work, a rational design strategy is presented for the development of oligonucleotide probes based upon repeated sequence families. A repeated sequence family present in the genome of Onchocerca parasites, designated O-150, has been amplified from various samples of genomic DNA using PCR. DNA sequence analysis of the resulting PCR products demonstrated that the sequences may be arranged into clusters within which the individual sequences are identical or nearly identical. Differences among the cluster consensus sequences have been exploited to explain the specificities of previously isolated O-150 based probes and to develop two new oligonucleotide probes. One of these probes hybridizes specifically to Onchocerca volvulus O-150 PCR products, while the second hybridizes specifically to O-150 PCR products from the closely related bovine parasite O. ochengi. These oligonucleotide probes have been used to characterize Onchocerca infective larvae isolated from wild caught infected flies in West Africa. Because repeated sequence families are a common feature of most genomes, including those of parasites, this method should be applicable to the rational design of oligonucleotide probes for other parasitic infections.
Mol Biochem Parasitol 1993 Apr
PMID:Design of Onchocerca DNA probes based upon analysis of a repeated sequence family. 847 50

Filarial parasites release macromolecules into their environment both in vitro and in vivo. These excretory-secretory products (E-S) have been studied with respect to function, vaccination potential, pathogenicity, and ability to serve as antigen targets for diagnostic tests. We have recently described monoclonal antibody OV-1 which binds to an intermediate filament in E-S and circulating antigens of Onchocerca volvulus. OV-1 also binds to cross-reactive antigens of Brugia malayi. Therefore, OV-1 was used to immunoscreen a B. malayi adult worm cDNA library in an attempt to clone a homologue (BMIF). BMIF is a 1664-bp full-length transcript which codes for 505 amino acids. BMIF has 95% sequence homology at the amino-acid level to OV1CF, an O. volvulus intermediate filament that was also selected with OV-1, and 75% homology to Ascaris intermediate filament A. Southern blot analysis suggests that BMIF is confined to a single location in the genomic DNA of B. malayi. Antibodies raised to BMIF identified native antigens in immunoblots of B. malayi adult worms, infective larvae and adult E-S. In addition, the antibody also bound to a 60-kDa antigen in immunoblots of poly(ethylene glycol)-precipitated immune complexes in sera from B. malayi infected patients. Localization studies showed that the antigen encoded by BMIF is present in the hypodermis, developing embryos and muscle of adult B. malayi. These studies show that BMIF is an E-S product of B. malayi adult worms which is detectable in sera from patients with brugian filariasis.
Mol Biochem Parasitol 1995 Jul
PMID:Molecular characterization of a Brugia malayi intermediate filament protein which is an excretory-secretory product of adult worms. 857 31

Genomic clones coding for actin have been isolated from two species of the crustacean Artemia, A. parthenogenetica and A. franciscana. The Act211 isoform gene was isolated from A. parthenogenetica, and the two other isoform genes, Act302 and Act403, were isolated from A. franciscana. The comparison of the nucleotide sequence of genomic and cDNA clones showed an interspecific divergence of 4% in translated and 6.1% in untranslated regions. However, the establishment of the partial structure of the Act211 gene in A. franciscana and of the Act302 gene in A. parthenogenetica suggests their similarity in the two species. The Act211 gene is divided into four exons, the Act302 gene into six exons, and the Act403 gene into seven exons. The three genes have introns in the 5' untranslated region and between codons 41 and 42. The Act211 and 403 genes have one common intron in codon 168. The Act302 and 403 genes have common introns between codons 121-122, 246-247, and within codon 301. While introns in the 5' untranslated region and between codons 41-42 and 121-122 are present in many organisms, the introns in positions 168 and 246-247 had only been found previously in actin genes from the nematode Onchocerca volvulus and the green alga Volvox carterii, respectively. The intron in position 301 had not been reported before. The transcription initiation sites of these three genes as well as the nucleotide sequences of the promoter regions have been also determined.
J Mol Evol 1996 Sep
PMID:Actin gene structure in two Artemia species, A. franciscana and A. parthenogenetica. 870 88


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>