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)

From the fruiting bodies of the mushroom Lyophyllum shimeji, a novel ribosome inactivating protein with a molecular weight of 20 kDa and exhibiting antifungal activity against Physalospora piricola (IC(50) = 2.5 microM) and Coprinus comatus was isolated. The protein, designated lyophyllin, was purified by ion exchange chromatography on CM-cellulose, affinity chromatography on Affi-gel Blue Gel, and then ion exchange chromatography on Mono S. Lyophyllin possessed an N-terminal sequence with some similarity to those of plant ribosome-inactivating proteins. It inhibited translation in rabbit reticulocyte lysate with an IC(50) of 1 nM, thymidine uptake by murine splenocytes with an IC(50) of 1 microM and HIV-1 reverse transcriptase activity with an IC(50) of 7.9 nM. Lyophyllin did not manifest ribonuclease or hemagglutinating activity. An antifungal protein, designated Lyophyllum antifungal protein (LAP), with a molecular weight of 14 kDa, and an N-terminal sequence somewhat analogous to those of angiosperm thaumatin-like proteins and thaumatins and an inactive variant of the ubiquitin-conjugating enzyme, was first isolated from Lyophyllum shimeji. LAP was adsorbed on CM-cellulose, Affi-gel blue gel, and Mono S. LAP exerted antifungal activity against P. piricola (IC(50) = 70 nM) and Mycosphaerella arachidicola but not against Rhizoctonia solani, Colletotrichum gossypii, and Coprinus comatus. It exerted very low translation inhibitory activity in a rabbit reticulocyte lysate system (IC(50) = 70 microM) and negligible ribonuclease activity toward yeast transfer RNA and hemagglutinating activity toward rabbit erythrocytes. It inhibited HIV-1 reverse transcriptase with an IC(50) of about 5.2 nM. A synergism in antifungal activities of LAP and lyophyllin against P. piricola was demonstrable.
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PMID:First simultaneous isolation of a ribosome inactivating protein and an antifungal protein from a mushroom (Lyophyllum shimeji) together with evidence for synergism of their antifungal effects. 1155 14

A deoxyribonuclease distinct from the previously isolated asparagus ribosome-inactivating proteins, possessing a molecular weight of 30 kDa and requiring a pH of 7.5 for optimum hydrolytic activity toward herring sperm DNA, was isolated from Asparagus officinalis seeds. The isolation procedure involved extraction with saline, (NH(4))(2)SO(4) precipitation, ion-exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion-exchange chromatography on CM-Sepharose, and FPLC gel filtration on Superdex 75. The doxyribonuclease was unadsorbed onto DEAE-cellulose and Affi-gel blue gel and adsorbed onto CM-Sepharose. It exhibited the novel N-terminal sequence, GIEVIKIREL. The deoxyribonuclease was purified to a specific activity of 1584 units/mg. It was devoid of ribonuclease, protease, and HIV-1 reverse transcriptase-inhibitory activities. However, it inhibited cell-free translation in a rabbit reticulocyte lysate system with an IC(50) of 20 microM. It exhibited antifungal activity toward Botrytis cinerea but not toward Fusarium oxysporum and Mycosphaerella arachidicola.
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PMID:Isolation of a novel deoxyribonuclease with antifungal activity from Asparagus officinalis seeds. 1170 87

A protease designated pleureryn, with an N-terminal sequence dissimilar from previously reported mushroom metalloendopeptidases and showing only limited resemblance to aspartic proteinases, albeit considerable homology to DNA replication licensing factor, was isolated from fresh fruiting bodies of the edible mushroom Pleurotus eryngii. The purification protocol entailed ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel Blue gel, ion exchange chromatography on CM-Sepharose, and FPLC-gel filtration on Superdex 75. The protease was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel Blue gel and CM-Sepharose. It demonstrated a single band with a molecular weight of 11.5 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Pleureryn demonstrated a protease activity of 9364 U/mg toward casein. It exhibited a pH optimum of 5.0 and a temperature optimum of 45 degrees C, with substantial activity remaining at high temperatures and pH 4 and 12. The activity of the protease was adversely affected by pepstatin A, indicating that it is an aspartic protease. PMSF, trypsin inhibitor, and EDTA exerted no striking effect, suggesting that it is neither a serine protease nor a metalloprotease. It inhibited translation in a rabbit reticulocyte lysate system with an IC(50) of 20 nM. Pleureryn also exhibited some inhibitory activity against HIV-1 reverse transcriptase, reminiscent of a suppressive action of HIV-1 protease on its homologous reverse transcriptase but was devoid of ribonuclease, deoxyribonuclease, and antifungal activities.
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PMID:Pleureryn, a novel protease from fresh fruiting bodies of the edible mushroom Pleurotus eryngii. 1172 12

A protein designated unguilin was isolated from seeds of the black-eyed pea (Vigna unguiculata). It possesses a molecular weight of 18 kDa and an N-terminal sequence resembling that of cyclophilins and the cyclophilin-like antifungal protein from mung beans, and was adsorbed on Affi-gel blue gel and CM-Sepharose. Unguilin exerted an antifungal effect toward fungi including Coprinus comatus, Mycosphaerella arachidicola, and Botrytis cinerea. In addition, unguilin was capable of inhibiting human immunodeficiency virus-1 reverse transcriptase and the glycohydrolases a- and beta-glucosidases which are involved in HIV infection. Unguilin was devoid of lectin and ribonuclease activities. It inhibited methyl-3H-thymidine uptake by mouse splenocytes and it weakly inhibited translation in a rabbit reticulocyte lysate system. Unguilin resembles mungin in some aspects, but differs from it in others.
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PMID:Isolation of unguilin, a cyclophilin-like protein with anti-mitogenic, antiviral, and antifungal activities, from black-eyed pea. 1173 86

Using molecular modelling studies, an active anti-HIV ethidium-arginine conjugate targeted against the viral TAR RNA sequence has been linked to an artificial ribonuclease, with the aim to obtain an irreversible inhibitor. The ribonuclease moiety consists of an N-[N-(3-aminopropyl)-3-aminopropyl] glycine and has been constructed via two successive N-alkylations following the Fukuyama procedure.
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PMID:Modelling, synthesis and biological evaluation of an ethidium-arginine conjugate linked to a ribonuclease mimic directed against TAR RNA of HIV-1. 1212 76

Dichloromethane, methanol and aqueous extracts from the leaves of Terminalia triflora were investigated for their inhibitory effect on polymerase and ribonuclease activities of HIV reverse transcriptase.The most potent activity was found in the aqueous extract, which inhibited both polymerase and ribonuclease activities of the enzyme with an IC50 of 1.6 micro g/mL and 1.8 micro g/mL respectively. The antiinfective activity of the extract was demonstrated in HLT4LacZ-IIIB cell culture with an IC50 of 1.0 micro g/mL. The extract was submitted to a purification process by extractive and chromatographic methods. The activity remained in the hydrophillic fraction. Tannins present in this active purified fraction, as determined by TLC and HPLC methods, could account for the anti HIV-RT activity found in the aqueous extract.
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PMID:Inhibitory effect against polymerase and ribonuclease activities of HIV-reverse transcriptase of the aqueous leaf extract of Terminalia triflora. 1245 88

Human immunodeficiency virus type 1 (HIV-1)-infected mononuclear phagocytes (MP; brain macrophages and microglia) secrete a number of toxic factors that affect the pathogenesis of HIV-1-associated dementia (HAD). The identification and relative role of each MP toxin for neuronal dysfunction during HAD are not well understood. Interleukin-8 (IL-8), a CXC chemokine involved in leukocyte activation and chemotaxis, is constitutively produced by MP, and elevated levels of IL-8 mRNA were detected in the brains of patients with HIV-1 encephalitis (HIVE) by both ribonuclease protection assays and real-time PCR. To determine the role that IL-8 might play in the neuronal dysfunction in HAD, we studied its effect on synaptic transmission and plasticity in the CA1 region of hippocampus, the seat of learning and memory. Bath application of IL-8 (50 ng/ml) to rat hippocampal slices had no effect on basal synaptic transmission. However, IL-8 was shown to inhibit long-term potentiation (LTP) in a concentration-dependent manner. In control and IL-8-treated slices, the LTP magnitudes were 167.8% +/- 11.9% (mean +/- SE; n = 17) and 122.2% +/- 16.2% of basal levels (n = 13), respectively. These differences were statistically significant (P < 0.05). Preincubation of hippocampal slices with a monoclonal CXCR2 antibody (2 microg/ml) but not control IgG (2 microg/ml) blocked IL-8-induced inhibition of LTP. The expression of CXCR2 receptors in the CA1 region was shown by Western blot assays. The induction of IL-8 in HAD, its inhibition of LTP, and the expression of its receptor, CXCR2, in the hippocampus all suggest that it plays a role in the cognitive dysfunction associated with HAD.
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PMID:Inhibition of long-term potentiation by interleukin-8: implications for human immunodeficiency virus-1-associated dementia. 1254 17

Astrocytes may be infected with the human immunodeficiency virus type 1 (HIV-1) or exposed to the HIV protein gp120, yet their role in the pathogenesis of HIV dementia is largely unknown. To characterize the effects of HIV on astrocytic transcription, microarray analysis and ribonuclease protection assays (RPA) were performed. Infection of astrocytes by HIV or treatment with gp120 had differential and profound effects on gene transcription. Of the 1153 oligonucleotides on the immune-based array, the expression of 108 genes (53 up; 55 down) and 82 genes (32 up; 50 down) were significantly modulated by gp120 and HIV infection respectively. Of the 1153 oligonucleotides on the neuro-based array, 58 genes (25 up; 33 down) and 47 genes (17 up; 30 down) were significantly modulated by gp120 and HIV infection respectively. Chemokine and cytokine induction occurred predominantly by HIV infection, whereas gp120 had no significant effect. These results were confirmed by RPA. The authors conclude that profound alterations of astrocytic function occur in response to HIV infection or interaction with viral proteins, suggesting that astrocytes may play an important role in the pathogenesis of HIV dementia.
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PMID:Differential transcriptional regulation by human immunodeficiency virus type 1 and gp120 in human astrocytes. 1277 19

A ribonuclease that is co-specific for poly C and poly U has been isolated from the fruiting bodies of the black oyster mushroom. The enzyme possesses a molecular mass of 14 kDa, and is unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and CM-cellulose. A pH of 7 is required for the enzyme to exhibit maximal activity. The activity of the enzyme does not vary appreciably over the temperature range 30-60 degrees C, but drops when the temperature is reduced to 20 degrees C or raised to and above 70 degrees C. The ribonuclease does not exert any inhibitory activity toward HIV-1 reverse transcriptase.
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PMID:A new ribonuclease from the black oyster mushroom Pleurotus ostreatus. 1516 25

We present here the design of a novel class of RNA inhibitors of the RNase H domain of HIV-1 RT, a ribonuclease activity that is essential for viral replication in vivo. Specifically, we show that small RNA hairpins and dumbbells can selectively inhibit the RNase H activity of HIV-1 RT without affecting other cellular RNases H (e.g., E. coli and human RNase H). These results suggest that the inhibitors do not interact with the nucleic acid binding site of RT RNase H, as this region should be well conserved among the various enzymes. The most potent inhibitors displayed IC50 values in the 3-8 microM range. Remarkably, the DNA polymerase activity, an intrinsic property of HIV RT, was not inhibited by the hairpin and dumbbell aptamers, a property not previously observed for any nucleic acid aptamer directed against RT RNase H. The results described here suggest a noncompetitive binding mechanism, as outlined in the differential inhibitory characteristics of each of the nucleic acid aptamers against the bacterial, human, and viral RNase H homologues.
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PMID:Selective inhibition of HIV-1 reverse transcriptase (HIV-1 RT) RNase H by small RNA hairpins and dumbbells. 1518 77


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