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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have investigated the extent of hepatitis delta virus (HDV) genetic variability after serial passages in chimpanzees and woodchucks and between different human isolates. A complete HDV genome, isolated from a woodchuck liver, was cloned after five serial transmissions. The 1679 nucleotide long genome revealed only point mutations and a nucleotide divergence of 0.65% and 0.89% with previously published sequences of two epidemiologically related HDVs. We have obtained partial nucleotide sequences of two unrelated human HDV cDNAs by using the polymerase chain reaction. When compared to the woodchuck HDV strain and other previously reported isolates, a perfectly conserved region of 90 nucleotides was shown in the region encompassing the delta antigen antigenomic self-cleavage site. In woodchuck and human HDV strains, the two forms of delta protein (195 and 214 amino acids) were potentially expressed. Our study indicates that only a limited genetic variability is generated by several passages in animals despite significant modification of pathogenicity during these transmissions.
J Gen Virol 1991 Mar
PMID:Nucleotide sequence analysis of three different hepatitis delta viruses isolated from a woodchuck and humans. 200 38

The hepatitis delta antigen (HDAg) is a multifunctional protein. It forms the core-like structure of the hepatitis delta virus (HDV) but also enhances replication of HDV in the nucleus of the hepatocyte. A cDNA fragment encoding HDAg was inserted adjacent to the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus present in the baculovirus transfer vector pVL941. After transfection of Spodoptera frugiperda (Sf9) cells a recombinant baculovirus Ac delta 1 was isolated and purified using filter hybridization techniques. Sf9 cells infected with Ac delta 1 express the HDAg as a non-fused, non-glycosylated protein with an abundance of up to 25% of the total cellular protein mass. Immunoblot analysis using a human polyclonal anti-HD conjugate identified a 22K and a 24K protein in the nucleus of Ac delta 1-infected Sf9 cells. Electron microscopic studies using immunogold labelling showed that the recombinant HDAg (recHDAg) was associated with the hetero-chromatin of the Sf9 cells. The recHDAg produced by Sf9 cells elicited anti-HD antibodies in chimpanzees when injected intramuscularly.
J Gen Virol 1991 Apr
PMID:Baculovirus-directed high level expression of the hepatitis delta antigen in Spodoptera frugiperda cells. 201 95

The nucleotide sequence of the S peplomer gene of bovine coronavirus (BCV) has been determined. A single open reading frame of 4089 nucleotides encodes a polypeptide of 150K with 20 potential sites for addition of N-linked oligosaccharides. Expression of the cloned BCV S gene by a recombinant of Autographa californica nuclear polyhedrosis virus resulted in production of a 180K glycosylated polypeptide which was transported to the surface of the cell. Comparison of the BCV S gene with the analogous genes of murine hepatitis viruses shows that the BCV S polypeptide contains a unique domain of 138 amino acids not present in murine hepatitis virus strain JHM, but which has a partially homologous counterpart in strain A59. This domain accounts for most of the differences in size of the S gene products of these coronaviruses.
J Gen Virol 1990 Feb
PMID:Primary structure of the S peplomer gene of bovine coronavirus and surface expression in insect cells. 215 83

The gene encoding the spike glycoprotein (S) of bovine enteric coronavirus (BECV) was cloned and its complete sequence of 4092 nucleotides was determined. This sequence contained a single long open reading frame with a coding capacity of 1363 amino acids (Mr 150,747). The predicted protein had 19 N-glycosylation sites. A signal sequence comprising 17 amino acids was observed starting from the first methionine residue. A potential peptidase cleavage site was located between amino acids 763 and 767. These cleavage explain the maturation of the primary product of the S gene to S1 (Mr 104,692) and S2 (Mr 84,175) spike structural proteins. Two amphipathic alpha-helices (amino acids 1007 to 1077 and 1269 to 1294) which may constitute the 12 nm stalk of the viral spike were also observed; another alpha-helix (amino acids 1305 to 1335) may be involved in the anchorage of the spike in the viral membrane. Comparison of this protein sequence to the described homologous mouse hepatitis (MHV) strain A59 and MHV-JHM S protein sequences led us to suggest that MHV-A59 and MHV-JHM S genes could be derived from a deletion of the BECV S gene.
J Gen Virol 1990 Feb
PMID:Nucleotide sequence of the glycoprotein S gene of bovine enteric coronavirus and comparison with the S proteins of two mouse hepatitis virus strains. 215

A 5 bp insertion was introduced into the BstEII site at nucleotide 2815 in DNA of hepatitis B virus (HBV) and a mutant HBV genome was produced, which coded for envelope and core proteins, but not for DNA polymerase, due to a frameshift. Cultured hepatoma cells (HepG2) were simultaneously transfected with a plasmid harbouring a tandem dimer of the mutant HBV DNA and another plasmid harbouring a tandem dimer of DNA of woodchuck hepatitis virus or duck hepatitis B virus. The replication of mutant HBV DNA, incapable of encoding DNA polymerase, was accomplished by cotransfecting woodchuck hepatitis virus DNA, but not by duck hepatitis B virus DNA. These results indicated a trans-complementation of the C and P genes in mammalian hepadnaviruses beyond a species barrier.
J Gen Virol 1990 Apr
PMID:Trans-complementation of the C gene of human and the P gene of woodchuck hepadnaviruses. 215 4

Blood-borne type non-A, non-B (NANB) hepatitis-associated microtubular aggregates protein was isolated and partially sequenced. The microtubular aggregates were isolated from the hepatocytes of NANB-infected chimpanzees and were found to have a buoyant density in sucrose solution of 1.21 to 1.23 g/ml. A single protein, recognized by our anti-microtubular aggregates monoclonal antibodies, was found to have an Mr of 44,000 (p44). This p44 protein was not found in uninfected chimpanzees. We determined a partial amino acid sequence for p44, and showed that it has no homology to any known proteins.
J Gen Virol 1990 Sep
PMID:Isolation and purification of a non-A, non-B hepatitis-associated microtubular aggregates protein. 217 May 69

A 1.7 kb cDNA encoding a novel antigen (p44; apparent Mr 44K) associated with non-A, non-B (NANB) hepatitis, was isolated from the hepatic cDNA library of a chimpanzee infected with NANB hepatitis. The library was screened with a monoclonal antibody against this antigen. The cDNA cloned contained an open reading frame encoding a 444 amino acid protein with an Mr calculated to be 50,468. The cDNA hybridized to a 1.9 kb mRNA obtained from chimpanzee hepatocytes infected with either the NANB or hepatitis delta viruses. It hybridized weakly to mRNA from hepatitis B virus-infected hepatocytes, and not at all to mRNA from normal chimpanzee hepatocytes. Southern blot analysis revealed that p44 is a host protein in chimpanzees, and that an identical gene exists in the human genome.
J Gen Virol 1990 Sep
PMID:Cloning, sequencing and expression in Escherichia coli of cDNA for a non-A, non-B hepatitis-associated microtubular aggregates protein. 217 May 70

The gene encoding the spike glycoprotein of the human coronavirus HCV 229E has been cloned and sequenced. This analysis predicts an S polypeptide of 1173 amino acids with an Mr of 128,600. The polypeptide has 30 potential N-glycosylation sites. A number of structural features typical of coronavirus S proteins can be recognized, including a signal sequence, a membrane anchor, heptad repeat structures and a carboxy-terminal cysteine cluster. A detailed, computer-aided comparison with the S proteins of infectious bronchitis virus, feline infectious peritonitis virus, transmissible gastroenteritis virus and murine hepatitis virus, strain JHM is presented. We have also done a Northern blot analysis of viral RNAs in HCV 229E-infected cells using synthetic oligonucleotides. On the basis of this analysis, and by analogy to the replication strategy of other coronaviruses, we are able to propose a model for the organization and expression of the HCV 229E genome.
J Gen Virol 1990 May
PMID:Nucleotide sequence of the gene encoding the spike glycoprotein of human coronavirus HCV 229E. 234 67

The RNA of hepatitis delta virus (HDV) 1682 nucleotides long, has been cloned from a human serum isolate. Comparison with the three complete published sequences shows that a region of the HDV genome, between positions 620 and 1350, which contains sequences involved in replication and possibly pathogenicity, is highly conserved.
J Gen Virol 1990 Jul
PMID:Cloning and sequencing of RNA of hepatitis delta virus isolated from human serum. 237 10

A cDNA clone prepared from hepatitis delta virus (HDV) RNA extracted from human serum was subcloned in the bacterial expression vector pPL31 to produce a fusion protein consisting of the first 98 amino acids of MS2 polymerase and of 64 amino acids from near the N-terminal region of hepatitis delta antigen (HDAg). The fusion protein was shown to be related to HDAg by a commercial sandwich immunoassay (Abbott) and immunoblotting with human anti-HDAg serum. Antiserum against the fusion protein was raised in rabbits and used to identify HDAg extracted from the serum and liver of an HDV-infected woodchuck and chimpanzee and from the serum of an HDV-infected human, by immunoblotting and immunohistology. A single, major polypeptide of 24K was detected in both serum and liver extracts, with a minor polypeptide of 26K sometimes present. Liver extracts also contained lower Mr polypeptides thought to be degradation products, the major species being 22.5K. The same pattern of staining was obtained with human anti-HDAg serum. Absorption experiments with the expressed protein and cross-competition experiments with the rabbit antiserum suggest that a major immunodominant region of HDAg is present near the N-terminal end of the antigen, between positions 1561 and 1368 on the genome. Both the expressed protein and rabbit antiserum were shown to be good diagnostic reagents.
J Gen Virol 1990 Feb
PMID:Cloning and expression of an immunodominant region of the hepatitis delta antigen. 240 5


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