Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A two-fold (C2) symmetric inhibitor of the protease of human immunodeficiency virus type-1 (HIV-1) has been designed on the basis of the three-dimensional symmetry of the enzyme active site. The symmetric molecule inhibited both protease activity and acute HIV-1 infection in vitro, was at least 10,000-fold more potent against HIV-1 protease than against related enzymes, and appeared to be stable to degradative enzymes. The 2.8 angstrom crystal structure of the inhibitor-enzyme complex demonstrated that the inhibitor binds to the enzyme in a highly symmetric fashion.
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PMID:Design, activity, and 2.8 A crystal structure of a C2 symmetric inhibitor complexed to HIV-1 protease. 220 Jan 22

The intermediate filament proteins vimentin, desmin, and glial fibrillary acidic protein are cleaved in vitro by human immunodeficiency virus type 1 protease (HIV-1 PR). Microsequencing showed that HIV-1 PR cleaved both human and murine vimentin between leucine-422 and arginine-423 within the sequence between positions 418 and 427, Ser-Ser-Leu-Asn-Leu/Arg-Glu-Thr-Asn-Leu (SSLNL/RETNL). Minor cleavages at other sites were also observed. Heat-denatured vimentin was cleaved by HIV-1 PR less efficiently than native vimentin. A decapeptide containing the sequence SSLN-LRETNL was also cleaved in vitro by HIV-1 PR as predicted. The presence of a charged residue (arginine) at the primary cleavage site distinguishes this from other known naturally occurring cleavage sites. Microinjection of HIV-1 PR into cultured human fibroblasts resulted in a 9-fold increase in the percentage of cells with an altered and abnormal distribution of vimentin intermediate filaments. Most commonly, the intermediate filaments collapsed into a clump with a juxtanuclear localization. These results support the possibility that intermediate filament proteins may serve as substrates within HIV-1-infected cells.
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PMID:Human immunodeficiency virus type 1 protease cleaves the intermediate filament proteins vimentin, desmin, and glial fibrillary acidic protein. 220 Oct 25

A procedure is described which employs pepstatin-agarose for the affinity purification of either HIV-1 or HIV-2 protease from two similar recombinant E. coli constructs that were developed for the expression of these enzymes. HIV-2 protease was routinely expressed at much higher levels than the HIV-1 enzyme and pepstatin-agarose was the only chromatography step required to isolate pure HIV-2 protease from crude bacterial lysates. A Mono S ionic exchange step following pepstatin-agarose chromatography was sufficient to bring the HIV-1 protease to homogeneity. Purification of either enzyme can be completed in several days yielding homogeneous preparations suitable for crystallization and other physical characterization.
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PMID:Affinity purification of HIV-1 and HIV-2 proteases from recombinant E. coli strains using pepstatin-agarose. 220 50

By using a structure-based computer-assisted search, we have found a butyrophenone derivative that is a selective inhibitor of the human immunodeficiency virus 1 (HIV-1) protease. The computer program creates a negative image of the active site cavity using the crystal structure of the HIV-1 protease. This image was compared for steric complementarity with 10,000 molecules of the Cambridge Crystallographic Database. One of the most interesting candidates identified was bromperidol. Haloperidol, a closely related compound and known antipsychotic agent, was chosen for testing. Haloperidol inhibits the HIV-1 and HIV-2 proteases in a concentration-dependent fashion with a Ki of approximately 100 microM. It is highly selective, having little inhibitory effect on pepsin activity and no effect on renin at concentrations as high as 5 mM. The hydroxy derivative of haloperidol has a similar effect on HIV-1 protease but a lower potency against the HIV-2 enzyme. Both haloperidol and its hydroxy derivative showed activity against maturation of viral polypeptides in a cell assay system. Although this discovery holds promise for the generation of nonpeptide protease inhibitors, we caution that the serum concentrations of haloperidol in normal use as an antipsychotic agent are less than 10 ng/ml (0.03 microM). Thus, concentrations required to inhibit the HIV-1 protease are greater than 1000 times higher than the concentrations normally used. Haloperidol is highly toxic at elevated doses and can be life-threatening. Haloperidol is not useful as a treatment for AIDS but may be a useful lead compound for the development of an antiviral pharmaceutical.
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PMID:Structure-based design of nonpeptide inhibitors specific for the human immunodeficiency virus 1 protease. 220 60

Recombinant vaccinia viruses that contained regions of the gag-pol open reading frames of human immunodeficiency virus type 1 (HIV-1) were constructed. Cells infected with recombinants containing both gag and protease genes expressed and processed HIV gag antigens efficiently. Processing was much reduced in cells infected with recombinants containing only gag, but not the protease gene. However, significant amounts of p41 were produced by protease-defective recombinants. This protein was immunoreactive with p24-specific monoclonal antibodies and was produced in a truncated form by a recombinant containing a 3' deletion in the p15 coding region of gag ORF. These results indicate that p41 could represent an alternative gag precursor with N-terminal sequences derived from p24 and C-terminal from p15. Ultrastructural analysis of recombinant-infected cells revealed that the gag antigens expressed were assembled into retrovirus-like particles and were secreted into culture medium. This assembly process was not dependent on HIV protease function, because immature core particles were produced by recombinants lacking HIV-1 protease functions. Immunization of mice and chimpanzees with vaccinia-HIVgag recombinant viruses generated both antibody and cell-mediated immune responses to HIV gag antigens. These recombinants are therefore useful not only for studying HIV virion processing and assembly, but also for designing immunogens for the prophylaxis and immunotherapy against AIDS.
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PMID:Processing, assembly, and immunogenicity of human immunodeficiency virus core antigens expressed by recombinant vaccinia virus. 221 27

The ability of two novel synthetic compounds to inhibit the HIV protease-mediated processing of HIV-1 precursor polyproteins was investigated in an in vitro gag-protease mixed lysate assay system and in an assay using recombinant baculoviruses engineered to express the HIV-1 gag and pol genes in cultured insect cells. With the in vitro mixed lysate assay we have shown that both compounds at 1 microM can completely inhibit the HIV-1 and HIV-2 protease-mediated release of p24 from the HIV-1 gag precursor at pH 5.5 and pH 7.0. In the intracellular baculovirus system these compounds were shown to inhibit the protease-mediated maturation of gag and also the excision of the protease moiety from its precursor.
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PMID:Effect of two novel inhibitors of the human immunodeficiency virus protease on the maturation of the HIV gag and gag-pol polyproteins. 221 37

A synthetic peptidemimetic substrate of the human immunodeficiency virus 1 (HIV-1) protease with a nonhydrolyzable pseudodipeptidyl insert at the protease cleavage site was prepared. The peptide U-81749 inhibited recombinant HIV-1 protease in vitro (inhibition constant Ki of 70 nanomolar) and HIV-1 replication in human peripheral blood lymphocytes (inhibitory concentration IC50 of 0.1 to 1 micromolar). Moreover, 10 micromolar concentrations of U-81749 significantly inhibited proteolysis of the HIV-1 gag polyprotein (p55) to the mature viral structural proteins p24 and p17 in cells infected with a recombinant vaccinia virus expressing the HIV-1 gag-pol genes. The HIV-1 like particles released from inhibitor-treated cells contained almost exclusively p55 and other gag precursors, but not p24. Incubation of HIV-like particles recovered from drug-treated cultures in drug-free medium indicated that inhibition of p55 proteolysis was at least partially reversible, suggesting that U-81749 was present within the particles.
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PMID:A synthetic HIV-1 protease inhibitor with antiviral activity arrests HIV-like particle maturation. 240 86

Recombinant HIV-1 reverse transcriptase (RT) was stably overproduced as a soluble protein in Escherichia coli using a double-plasmid expression system in which an RT precursor protein was expressed and processed in vivo by HIV-1 protease produced in trans. The RT thus produced consisted of an equimolar mixture of two polypeptides, p66 and p51, which were copurified to greater than 90% homogeneity and were found to share a common NH2 terminus as judged by sequence analysis of the polypeptide mixture. The observed sequence confirmed correct in vivo cleavage by protease at the protease-RT polyprotein junction to yield an NH2 terminus identical to that of genuine viral RT (M. M. Lightfoote et al. (1986) J. Virol. 60, 771-775; F. diMarzo Veronese et al. (1986) Science 231, 1289-1291). The bacterially expressed RT had a specific activity similar to that of viral RT and inhibition studies with phosphonoformate confirmed that it was indistinguishable from the viral enzyme with respect to sensitivity to this inhibitor. Polymerase activated gel analysis of the mixture indicated that p66 was associated with a higher level of RT activity than p51. RNase H activated gel analysis suggested that the purified preparation of recombinant RT was free of endogenous E. coli RNase H, and that the RNase H activity of RT was exclusively associated with the p66 polypeptide, supporting the hypothesis that the RNase H domain is located in the COOH-terminal region of the molecule.
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PMID:Recombinant HIV-1 reverse transcriptase: purification, primary structure, and polymerase/ribonuclease H activities. 247 69

The human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT)/ribonuclease H has been expressed to high levels in Escherichia coli from a recombinant plasmid constructed using the polymerase chain reaction (PCR) for in vitro mutagenesis. Translational initiation and termination codons were introduced by the PCR at points corresponding to sites of cleavage of the RT from the gag-pol precursor polyprotein by the HIV-1 protease; the HIV-1 protease is not expressed from this construct. Most of the RT coding sequences derived from PCR were exchanged for a DNA fragment cloned by standard methods to minimize the possibility that an unwanted mutation was introduced during the in vitro amplification. The RT is expressed in bacteria from this plasmid as 66 and 51 kDa proteins, has both RNA-dependent DNA polymerase and ribonuclease H (RNase H) activities, and is indistinguishable from native HIV-1 RT in electrophoretic mobility and immunoreactivity. Peptide sequencing of the amino terminus of the HIV-1 RT purified from bacterial lysates is also presented. A novel activity gel assay was used to confirm that only the 66 kd protein catalyzes the RNase H reaction; this assay will simplify analysis of this catalytic activity. This HIV-1 RT expression plasmid is of interest because of the high level of expression in bacteria and the demonstrated RNase H activity of the enzyme. This plasmid will be distributed for research purposes through the NIH AIDS Repository and will facilitate enzymologic, structural, and immunologic evaluation of reverse transcription and its chemotherapeutic inhibition.
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PMID:HIV-1 reverse transcriptase/ribonuclease H: high level expression in Escherichia coli from a plasmid constructed using the polymerase chain reaction. 247 33

The human immunodeficiency virus (HIV-1) encodes a protease that is essential for viral replication and is a member of the aspartic protease family. The recently determined three-dimensional structure of the related protease from Rous sarcoma virus has been used to model the smaller HIV-1 dimer. The active site has been analyzed by comparison to the structure of the aspartic protease, rhizopuspepsin, complexed with a peptide inhibitor. The HIV-1 protease is predicted to interact with seven residues of the protein substrate. This information can be used to design protease inhibitors and possible antiviral drugs.
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PMID:Molecular modeling of the HIV-1 protease and its substrate binding site. 253 31


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