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)

The TAR sequence of the 5' leader of HIV-1 long terminal repeat-directed mRNA was found to be able to bind to and to activate double-stranded RNA-dependent (2'-5')A synthetase. Binding of TAR to the purified synthetase in vitro was abolished by addition of HIV-1 Tat protein, which binds to this sequence with a high affinity. Inhibition of TAR-mediated activation of (2'-5')A synthetase by Tat was prevented in the presence of the Zn2+ and Cd2+ chelators o-phenanthroline and penicillamine, which did not impair TAR-synthetase interaction. Transient expression assays of bacterial chloramphenicol acetyltransferase (CAT) gene in HeLa cells revealed that the levels of both CAT mRNA and CAT protein decreased after treatment of the cells with interferon, if CAT gene was linked to HIV-1 TAR segment. Cotransfection of the cells with a tat sequence containing plasmid rendered CAT gene expression insensible to the action of interferon.
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PMID:Binding of Tat protein to TAR region of human immunodeficiency virus type 1 blocks TAR-mediated activation of (2'-5')oligoadenylate synthetase. 169 53

Human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type I (HTLV-I) were purified by sucrose density gradient centrifugation in the presence of 1 mM EDTA. Pelleted gradient fractions were analyzed for total protein, total Gag capsid protein, and total zinc. Zinc was found to copurify and concentrate with the virus particles. Through successive cycles of resuspending in buffer containing EDTA and repelleting, the zinc content remained constant at about 1.7 mol of zinc per mol of Gag protein. Proteins from purified virus (HIV-1 and HTLV-I) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted to polyvinylidene fluoride paper, and probed with 65ZnCl2. Viral nucleocapsid (NC) proteins (HIV-1 p7NC and HTLV-I p15NC) bound 65Zn2+. Other retroviruses, including simian immunodeficiency virus, equine infectious anemia virus, bovine leukemia virus, Moloney murine leukemia virus, mouse mammary tumor virus, and Mason-Pfizer monkey virus, were found to contain amounts of zinc per milligram of total protein similar to those found in HIV-1 and HTLV-I. Collectively, these data support the hypothesis that retroviral NC proteins function as zinc finger proteins in mature viruses.
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PMID:Tightly bound zinc in human immunodeficiency virus type 1, human T-cell leukemia virus type I, and other retroviruses. 173 Nov 11

We report here for the first time that Zn2+ is an effective inhibitor of renin and the protease from HIV-1, two aspartyl proteinases of considerable physiological importance. Inhibition of renin is noncompetitive and is accompanied by binding of 1 mol of Zn2+/mol of enzyme. Depending on the substrate, inhibition of the HIV protease by Zn2+ can be either competitive or noncompetitive, but in neither case is loss of activity due to disruption of the protease dimer. Inhibition of both enzymes is first order with respect to Zn2+ and is rapidly reversed by addition of EDTA. Ki values are strongly pH dependent and optimal in the range of 20 microM at or above pH 7. All of the data in hand suggest that the inhibitory effect of Zn2+ is a consequence of its binding at, or near, the active-site carboxyl groups of these aspartyl proteinases. This inhibition of the viral enzyme may help to explain some of the beneficial effects seen in AIDS patients who have received Zn2+ therapy.
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PMID:Zinc inhibition of renin and the protease from human immunodeficiency virus type 1. 188 32

Dietary, serum, and tissue levels of copper and zinc were determined at baseline in a cohort of homosexual men to investigate the relationship of these factors to human immunodeficiency virus type 1 (HIV-1) seropositivity and subsequent progression to AIDS. Using a nested case control design, 54 asymptomatic HIV-1 seropositives who later progressed to AIDS were compared with 54 HIV-1 seropositives who did not progress and 54 seronegatives (mean follow-up time 2.5 years). Serum levels of copper and zinc were estimated from frozen serum samples, tissue levels from stored toenail samples, and dietary intakes from a semiquantitative food frequency questionnaire administered at baseline. Neither dietary copper and zinc nor their levels in toenails were associated with HIV-1 seropositivity or progression to AIDS. However, serum copper levels were higher (p = 0.002) in HIV-1-seropositive progressors (mean = 115.6 micrograms/dl; SD = 17.1) than the seropositive nonprogressors (mean = 109.0 micrograms/dl; SD = 15.8) and the seronegatives (mean = 101.9 micrograms/dl; SD = 16.7). Conversely, serum zinc levels were lower (p = 0.016) in the seropositive progressors (mean = 85.2 micrograms/dl; SD = 11.5) than the seropositive nonprogressors (mean = 90.7 micrograms/dl; SD = 12.0) and the seronegatives (mean = 92.0 micrograms/dl; SD = 14.7). Furthermore, in a logistic regression, higher serum copper (odds ratio per 20-micrograms/dl increase = 2.23; 95% confidence interval = 1.02-4.87) and lower serum zinc (odds ratio per 20-micrograms/dl increase = 0.30; 95% confidence interval = 0.14-0.66) predicted progression to AIDS independently of baseline CD4+ lymphocyte level, age, and calorie-adjusted dietary intakes of both nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relationship of serum copper and zinc levels to HIV-1 seropositivity and progression to AIDS. 189 Jun 6

We report the synthesis in solid phase of an 18-amino acid peptide that contains the cysteine-rich region of the structural Gag protein of HIV-2. The characterization of this fragment and of its interaction with Zn2+ has been made by one- (1 D) and two-dimensional (2D) NMR techniques and by circular dichroism. Our results suggest that in aqueous solution the complexation produces a significant perturbation in the conformation of this peptide.
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PMID:[Study by NMR and circular dichroism of synthetic "zinc finger" peptide of viral Gag protein from HIV-2]. 191 57

Chemotherapeutic regimens frequently interact with and may influence nutritional factors. To determine the possible effects of zidovudine (ZDV) treatment on nutrient status, this study examined and compared the nutritional, immunological, and hematological status of asymptomatic, CDC stage III, HIV-1-seropositive males (n = 15) provided with ZDV (500-1,200 mg/day) and 22 nontreated, CD4-matched HIV-1-seropositive subjects. Prior to ZDV administration, hematological and plasma nutrient levels were similar in both groups. Following ZDV treatment, drug-treated subjects demonstrated alterations in hematological and nutritional parameters. A large proportion of the ZDV-treated participants exhibited decreased levels of zinc and copper along with a significant increase in red cell folate. The level of plasma zinc appeared to be particularly important in maintaining immune function in the ZDV-treated group. Whereas ZDV-treated subjects with adequate zinc levels displayed a significant increase in the response of peripheral blood lymphocytes to mitogens, this enhancement was not demonstrated in zinc-deficient, ZDV-treated participants or in untreated individuals whose lymphocyte response significantly declined over time, despite adeqaute zinc status. The findings of this study reveal a zidovudine-induced effect on nutritional parameters, indicating the importance of monitoring nutritional status with drug therapeutic regimens.
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PMID:Zidovudine-associated adverse reactions in a longitudinal study of asymptomatic HIV-1-infected homosexual males. 194 28

The nucleocapsid protein (NC) of the human immunodeficiency virus type 1 plays a crucial role in the formation of infectious viral particles and therefore should be a major target for the development of antiviral agents. This requires an investigation of NC protein structure and of its interactions with both primer tRNA(Lys,3) and genomic RNA. Nucleocapsid protein NCp7, which results from the maturation of NCp15, contains two zinc fingers flanked by sequences rich in basic and proline residues. Here we report the first synthesis of large quantities of NCp7 able to activate HIV-1 RNA dimerization and replication primer tRNA(Lys,3) annealing to the initiation site of reverse transcription. In addition UV spectroscopic analyses performed to characterize the Co2+ binding properties of each zinc finger suggest that the two fingers probably interact in NCp7.
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PMID:First large scale chemical synthesis of the 72 amino acid HIV-1 nucleocapsid protein NCp7 in an active form. 195 5

Plasma zinc and copper concentrations, erythrocyte zinc concentration, copper-zinc superoxide dismutase activity and urinary zinc concentrations were determined for control subjects and individuals with AIDS, ARC, or asymptomatic HIV infection. Significant differences among the population groups were not noted for the above parameters with the exception of plasma copper which was higher in the AIDS group than in other patient groups. These results do not support the idea that zinc deficiency is a common contributory factor of HIV infectivity or clinical expression, nor that HIV infection induces a zinc deficiency.
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PMID:Zinc status in human immunodeficiency virus infection. 197 59

Nuclear magnetic resonance (NMR) methods have been used to address issues regarding the relevance and feasibility of zinc binding to "zinc finger-like" sequences of the type C-X2-C-X4-H-X4-C [referred to as CCHC or retroviral-type (RT) zinc finger sequences]. One-dimensional (1D) NMR experiments with an 18-residue synthetic peptide containing the amino acid sequence of an HIV-1 RT-zinc finger domain (HIV1-F1) indicate that the sequences are capable of binding zinc tightly and stoichiometrically. 1H-113Cd spin echo difference NMR data confirm that the Cys and His amino acids are coordinated to metal in the 113Cd adduct. The 3D structure of the zinc adduct [Zn(HIV1-F1)] was determined to high atomic resolution by a new NMR-based approach that utilizes 2D-NOESY back-calculations as a measure of the consistency between the structures and the experimental data. Several interesting structural features were observed, including (1) the presence of extensive internal hydrogen bonding, and (2) the similarity of the folding of the first six residues to the folding observed by X-ray crystallography for related residues in the iron domain of rubredoxin. Structural constraints associated with conservatively substituted glycines provide further rationale for the physiological relevance of the zinc adduct. Similar NMR and structural results have been obtained for the second HIV-1 RT-zinc finger peptide, Zn(HIV1-F2). NMR studies of the zinc adduct with the NCP isolated directly from HIV-1 particles provide solid evidence that zinc finger domains are formed that are conformationally similar (if not identical) to the peptide structures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Zinc finger motif for single-stranded nucleic acids? Investigations by nuclear magnetic resonance. 200 83

The selenium concentration in the serum of 67 patients with HIV infection was measured to determine whether selenium deficiency occurred in the different stages of the disease. In the first stage of the study, patients were divided into four groups: symptom-free subjects, PGL (persistent generalized lymphadenopathy), ARC (AIDS related complex), and AIDS (acquired immunodeficiency syndrome). Selenium concentrations were normal in HIV antibody positive symptom-free subjects (1.18 +/- 0.27 mumol/L) and lower than normal in the other three groups (p less than 0.001). There was a significant correlation (p less than 0.001) between selenium levels and values of hemoglobin and erythrocyte sedimentation rate. Selenium deficiency was in no case associated with a lack of zinc in serum (also determined in all patients). In the second stage of the study, 12 patients were treated for a period of two months with low doses of selenium to assess whether such supplementation was able to restore their impaired immunological and hematological functions. The therapy increased serum selenium concentrations (from 0.77 +/- 0.23 to 1.44 +/- 0.41 mumol/L) and symptomatic improvements were noted. However, no changes were observed in the immunological and hematological parameters.
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PMID:Serum selenium concentration and disease progress in patients with HIV infection. 204 94


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