Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biochemical mechanisms underlying blood lymphoid cell genome destabilization in patients with HIV infection have been analyzed. Lymphocytes from HIV patients are characterized by increasing intensity of free radical oxidation together with activation of the xanthine oxidase D-form conversion into the O-form, enhanced activity of UV-endonuclease, and intensification of prooxidant-induced proteolysis. These changes increasing with the progress of the disease with a maximum at the AIDS stage form a metabolic basis for labilization of the lymph cell genome. The degree of biochemical manifestations of genome instability (levels of chromatin degradation products and intensity of formation of one-filament nicks of DNA) increase in the dynamics of HIV-infection. The data obtained are discussed in terms of the author's conception on the origin of AIDS from retroposons (retrotransposons?). A hypothesis is postulated on accumulation of autonomous genetic information on the basis of genome labilization under the influence of genotoxic factors. Clinico-biochemical data on the appearance of HIV proteins (p17, p24) in the blood of patients (previously negative for all HIV markers) in the presence of transfusions of HIV-negative blood and UV-irradiation of the autoblood are also discussed from this standpoint.
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PMID:[Genomic instability and AIDS]. 133 9

Rhodococcus species are ubiquitous in the environment, and several species have been reported to have pathogenic potential for humans. Rhodococcus equi, in particular, has been reported to cause infections in patients with AIDS. However, the identification of Rhodococcus species with use of conventional biochemical tests is problematic, and no simple and reproducible method exists for their rapid identification and differentiation. We found that the type strains of the 20 recognized species in the genus Rhodococcus could be clearly distinguished with use of a combination of the Pvu II and Pst I rRNA gene restriction endonuclease patterns and a digoxigenin-labeled Escherichia coli rDNA probe. Analysis of four clinical or environmental isolates confirmed as Rhodococcus bronchialis showed no interstrain variation of rRNA gene bands. Analysis of 15 isolates confirmed as R. equi from 13 patients showed 11 different rRNA gene patterns. No discernible difference was observed in the ribotype patterns between R. equi isolates from patients for whom AIDS had been diagnosed and those from patients who did not have AIDS, and there was no evidence of geographic clustering of R. equi ribotype patterns. Three of five Rhodococcus species isolates that could not be differentiated with use of conventional biochemical methods were identified with use of ribotype analysis. Therefore, ribotype analysis may provide an important adjunct to current biochemical identification of environmental and clinical isolates of Rhodococcus species.
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PMID:Identification and epidemiological typing of clinical and environmental isolates of the genus Rhodococcus with use of a digoxigenin-labeled rDNA gene probe. 138 20

Five strains of human immunodeficiency virus type 1 (HIV-1) were isolated from five Japanese hemophilia patients. Two isolates, HIV-1[GUN-1] and HIV-1[GUN-2], were from brother patients with hemophilia B and the other three isolates, HIV-1[GUN-3], HIV-1[GUN-4], and HIV-1[GUN-5], were from hemophilia A patients. Another HIV-1 strain, HIV-1[GUN-6], was isolated from a Canadian male homosexual with AIDS. The restriction endonuclease cleavage maps of the proviral genomes of these six HIV-1 strains revealed that they were apparently different from each other. The phylogenetic trees constructed using restriction maps and nucleotide sequences were quite similar, indicating that phylogenetic analyses of Japanese HIV-1 isolates can be done using restriction maps of the proviruses. Phylogenetic analyses showed that they were more closely related to HIV-1s which had been reported to be isolated from homosexual patients in the United States than those isolated from African patients. In particular, GUN-1 and GUN-2 isolates were on the branch of a San Francisco isolate, ARV2, while GUN-5 and GUN-6 isolates were on the branch of HTLV-IIIB-related isolates.
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PMID:Six strains of human immunodeficiency virus type 1 isolated in Japan and their molecular phylogeny. 140 18

The restriction-modification system, named RMMunI, has been purified and characterised from Friend murine erythroleukemia cells. The site-specific endonuclease recognizes and cleaves the 5'C1AATTG nucleotide sequence. RMunI is an isoschizomer of RMfeI from Mycoplasma fermentans. Site-specific methylase modifies the second adenine residue in the same sequence (5'Cam6ATTG). It was established that the discovered enzymatic system is from mycoplasma which contaminates cell lines. Mycoplasma's DNA hybridizes with species-specific DNA probed for Mycoplasma fermentans and Mycoplasma arginini. The possible role of mycoplasmic restriction-modification enzymes in the process of acquired immune deficiency syndrome are discussed.
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PMID:[Mycoplasma restriction-modification system MunI and its possible role in pathogenesis processes]. 140 10

The gag and pol genes of the human immunodeficiency virus type 1 (HIV-1) (ref. 1) are translated as two polyproteins, Pr55gag and Pr160gag-pol (refs 2-6), which are subsequently cleaved by the action of a virus-encoded protease into the four structural gag proteins of the virion core (p17, p24, p7 and p6) and the pol-encoded enzymes essential for retrovirus replication (protease, reverse transcriptase, ribonuclease H, and endonuclease). Mutational inactivation of the proteases of HIV-1 and other retroviruses results in immature, non-infectious virions, indicating that exogenous inhibition of the protease may represent an attractive approach to anti-AIDS therapy. Here we demonstrate that synthetic peptide analogues, which are potent inhibitors of purified HIV-1 protease, inhibit the processing of the viral polyproteins in cultures of HIV-1-infected T lymphocytes and attenuate viral infectivity.
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PMID:Inhibition of HIV-1 protease in infected T-lymphocytes by synthetic peptide analogues. 168 46

Human immunodeficiency virus type 1 (HIV-1) isolates from asymptomatic homosexual men and AIDS patients were compared for their in vitro biologic and genetic properties. Most of the HIV-1 isolates from asymptomatic men, but not from AIDS patients, failed to infect CD4+ H9 cells and phytohemagglutinin-stimulated peripheral blood lymphocytes. In a longitudinal study, serial HIV-1 isolates obtained from men who seroconverted to HIV-1 and later developed AIDS were able to infect H9 cells. In contrast, longitudinal isolates from men who remained asymptomatic did not infect H9 cells. HIV-1 isolates from AIDS patients in general exhibited increased production of intracellular viral DNA, RNA, and protein as compared to isolates from asymptomatic men. Cells infected with HIV-1 isolates from asymptomatic men produced very little gp120, p24, and p55 proteins as compared to those from AIDS patients. The overall restriction patterns of HindIII, Sac-1, Pst-1, EcoR1, and BamH1 were very similar between HIV-1 isolates from asymptomatic men and those from AIDS patients. However, the restriction endonuclease pattern of BglII was quite distinct for isolates from asymptomatic men as compared to AIDS patients. Preliminary studies mapped a unique BglII site in the gag region of most of the isolates from asymptomatic men, approximately 2.0 kb from the 5' end. Thus, HIV-1 isolates from asymptomatic subjects and from AIDS patients have distinct biologic and genetic properties which may be related to the various clinical outcomes of HIV-1 infection.
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PMID:Human immunodeficiency virus isolates from asymptomatic homosexual men and from AIDS patients have distinct biologic and genetic properties. 170 46

The HIV-1 pol gene proteins (protease, reverse transcriptase, and endonuclease) were expressed in Escherichia coli N4830-1 by the use of the inducible expression vector pWS60 into which the pol gene was inserted. The p66/p51 heterodimer of reverse transcriptase (RT) was isolated in a highly pure and active form. Crystals of the p66/p51 heterodimer were obtained by the vapor diffusion hanging drop technique. The present crystal quality is still not adequate for high resolution X-ray investigation.
AIDS Res Hum Retroviruses 1990 Nov
PMID:Expression, purification, and crystallization of the HIV-1 reverse transcriptase (RT). 170 8

Analysis of sera from hospitalized Brazilian patients by whole-virus lysate-based enzyme immunoassay and Western blot indicated that 0.4% were reactive to HIV-2 alone while 4% were reactive to both HIV-1 and HIV-2. When these sera were tested for HIV antibody by type-specific peptide enzyme immunoassays, dual seropositivity was confirmed in only 0.4% of patients. To define genetically the HIV strains within the population, we analyzed peripheral blood mononuclear cells from selected seropositive patients for the presence of HIV-1 and HIV-2 proviral DNA using the polymerase chain reaction (PCR). Independent primers/probes sets were used for the amplification and detection of viral sequences from the long terminal repeat (LTR), gag, and protease (prt) gene regions. Our findings confirmed the serologic evidence of HIV-2 in Brazil and determined the extent of mixed HIV-1 and HIV-2 infections. Detailed evaluation of the amplified viral protease sequences by endonuclease restriction analysis and DNA sequencing independently confirmed mixed HIV-1 and HIV-2 infections in the two patients seropositive for HIV-1 and HIV-2. The data further indicated that these isolates are distinct from the HIV laboratory standards. We interpret the combination of culture and PCR findings to demonstrate the presence of both HIV-1 and HIV-2 in Brazil.
AIDS 1991 Nov
PMID:Identification of mixed HIV-1/HIV-2 infections in Brazil by polymerase chain reaction. 176 77

A mycoplasma previously identified in the tissues of both AIDS and non-AIDS patients dying of an acute fatal disease was earlier shown to share some biologic and genetic properties with a strain of Mycoplasma fermentans, an organism occurring infrequently in the human lower urogenital tract. More extensive genetic and serologic comparisons using DNA/DNA hybridization, DNA base composition (guanine + cytosine), restriction endonuclease DNA analysis, cellular protein patterns and metabolism inhibition serologic procedures confirm that the organism previously designated as "Mycoplasma incognitus" (Mi) is indeed very closely related to strains of M. fermentans. While the genetic and serologic features observed among the newly isolated mycoplasma and two M. fermentans strains suggest a species relationship, it now seems useful to re-examine the biological activities of other freshly isolated M. fermentans strains from man.
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PMID:Genetic and serologic relatedness between Mycoplasma fermentans strains and a mycoplasma recently identified in tissues of AIDS and non-AIDS patients. 197 57

A HIV-2 strain named HIV-2ben was isolated from peripheral blood lymphocytes of a patient who, since 1984, had developed neurological symptoms such as Raynaud's syndrome, followed by paresthesia of extremities and ataxia, and finally paraparesis of the legs and incontinence. This new isolate could be distinguished from HIV-2rod by antibody-binding epitopes, peptide maps of core p24 and p18 polypeptides and restriction endonuclease cleavage pattern.
AIDS 1990 May
PMID:Isolation and characterization of HIV-2ben obtained from a patient with predominantly neurological defects. 211 42


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