Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The reverse transcriptase of the sheep lentivirus visna/maedi virus has been characterised. Optima for magnesium ion concentration (5-10 mM), potassium ion concentration (150 mM) and pH (8.25) for this enzyme are very similar to those previously described for the human immunodeficiency viruses. The assay used for this work makes use of a cell harvester to speed up the processing of multiple samples. It is small scale, requiring 15 microliters of sample, is rapid, and is able to detect virus at titres below 10(3)/ml. Harvesting the assay onto either DEAE paper or using TCA and glass fibre mats make it suitable for use with either tissue culture media or infected cell lysates, but not with body fluids. It has been used to detect cell-associated reverse transcriptase in choroid plexus cells within 36 h of visna infection.
 ...
PMID:Characterisation of visna virus reverse transcriptase: a micro scale reverse transcriptase assay adapted for use with an automated cell harvester. 137 10

Reverse transcriptase has been purified from feline immunodeficiency virus (FIV) by DEAE-cellulose and phosphocellulose chromatography. The purified enzyme consists of a single protein with a Mr of 67,000. When proteolysis is not minimized during purification, a fragment of Mr 54,000 is also observed. This is similar to the reverse transcriptase from human immunodeficiency virus type 1 (HIV), which consists of a polypeptide of Mr 66,000; when proteolysis is not minimized during purification, a fragment of Mr 51,000 is also observed. In direct comparisons, the FIV reverse transcriptase is very similar to the HIV reverse transcriptase in template specificity and requirements for Mg2+. In contrast to these similarities, the FIV and HIV reverse transcriptases are substantially different in primary sequence, as determined by peptide mapping.
 ...
PMID:Characterization of reverse transcriptase from feline immunodeficiency virus. 169 Jul 35

A simple and rapid solid-phase reverse transcriptase assay was developed based on the use of poly(rA):oligo(dT)12-18 as template primer immobilized on DEAE cellulose paper squares to detect human immunodeficiency virus (HIV) and/or other retroviruses in cell culture supernatants. It was found that PEG (per se) -up to 4% concentrations (w/v)--did not inhibit reverse transcriptase activity. Optimal conditions of the assay were determined. This solid-phase technique is much faster and more convenient than the methods described previously.
 ...
PMID:A solid phase reverse transcriptase micro-assay for the detection of human immunodeficiency virus and other retroviruses in cell culture supernatants. 169 Dec

The reverse transcriptase of human immunodeficiency virus type 1 is a heterodimeric protein consisting of two polypeptides with masses of 66 and 51 kDa and has, as a second enzymatic activity, RNase H activity. The 66-kDa polypeptide can be cleaved by the virus-encoded protease to yield polypeptides of 51 and 15 kDa. The latter has been characterized as possessing RNase H activity [Hansen, J., Schultze, T., Mellert, W. & Moelling, K. (1988) EMBO J. 7, 239-243]. We have purified simultaneously the heterodimeric reverse transcriptase/RNase H containing the 66/51-kDa polypeptides and the 15-kDa RNase H from Escherichia coli containing the expression vector pJS 3.7 by a procedure including chromatography on DEAE-cellulose, phosphocellulose, and heparin-Sepharose. Two RNase H and reverse transcriptase peaks were separated on phosphocellulose, one coinciding with the heterodimeric protein and the other with the 15-kDa protein. On the basis of the following findings it appears that the 15-kDa polypeptide has both RNase H and reverse transcriptase activities: (i) it copurified with both activities; (ii) it functioned as a reverse transcriptase in an in situ assay after SDS/polyacrylamide gel electrophoresis; (iii) polyclonal antibodies raised against the 66-kDa polypeptide reacted in immunoblots exclusively with a 15-kDa polypeptide, reacted in immunoblots exclusively with a 15-kDa polypeptide, while no immunoreactive bands in the range of 51-66 kDa were seen in the 15-kDa polypeptide preparation; (iv) the p15 and the p66/51 reverse transcriptase could be quantitatively pelleted in an enzymatically active form only when antibodies specific for the p66 carboxyl terminus were used; and (v) the p15 protein had bona fide properties of a reverse transcriptase and could enzymatically synthesize a high molecular weight, alkali-resistant product. The two reverse transcriptases appear to have different behaviors on various template/primer systems tested. Conceivably different forms of human immunodeficiency virus type 1 reverse transcriptases might be used in individual steps of (+)- and (-)-strand replication.
 ...
PMID:The p15 carboxyl-terminal proteolysis product of the human immunodeficiency virus type 1 reverse transcriptase p66 has DNA polymerase activity. 171 Dec 22

We have constructed the recombinant baculovirus which expresses the human immunodeficiency virus type 1 negative factor (nef) gene. Spodoptera frugiperda cells infected with the recombinant virus produced a 27-kDa protein which reacted with rabbit antisera raised against a carboxy-terminal synthetic peptide of the Nef protein by immunoblot analysis. Labeling experiment showed that the recombinant Nef protein was myristoylated. The recombinant Nef protein was purified to near homogeneity by DEAE-Sephacel, phenyl-Sepharose 4B, blue-Sepharose, and Sephadex G-150 column chromatography. No detectable GTP binding activity was observed in the purified recombinant Nef product.
 ...
PMID:Purification and characterization of human immunodeficiency virus type 1 nef gene product expressed by a recombinant baculovirus. 190 80

We have reported previously the enhancement of the infectivity of human immunodeficiency virus type 1 (HIV-1) by liposomes composed of the cationic lipid N-[2,3-(dioleyloxy) propyl]-N,N,N-trimethylammonium chloride (DOTMA). To determine the mechanism by which this process occurs, we have investigated the role of CD4, serum concentration and liposome-cell interactions in the DOTMA-mediated stimulation of HIV-1 infection of A3.01 cells. Serum alone significantly inhibited the binding and infectivity of HIV-1, but DOTMA-mediated enhancement of infectivity was more pronounced in the presence of serum than in its absence. HIV-1 binding to cells was increased in the presence of DOTMA liposomes, DEAE-dextran and polybrene, all of which also enhanced infectivity to a similar extent at comparable concentrations. Fluorescence dequenching measurements indicated that DOTMA liposomes fused with HIV-1, but not with cell membranes, in the presence of serum. The enhancing effect of DOTMA liposomes on HIV-1 infectivity was CD4-dependent, and appeared to involve virus-liposome fusion and liposome binding to the cell surface. DOTMA liposomes did not mediate infection of the CD4-K562 and Raji cell lines.
 ...
PMID:Enhancement of human immunodeficiency virus type 1 infection by cationic liposomes: the role of CD4, serum and liposome-cell interactions. 194 Aug 66

We showed that an extract (PC6) from cones of Pinus parviflora Sieb et Zucc induced the human T-cell line CEM to produce a pepsin-sensitive soluble factor(s) that could inhibit the replication of the type 1 human immunodeficiency virus (HIV-1) in CEM T cells, in U-937 histocytes, in THP-1 monocytes, and in mitogen-activated human tonsillar mononuclear cells. Indirect immunofluorescence staining and polymerase chain reaction analysis of the PC6-induced CEM cells revealed the absence of known lymphokines/cytokines except granulocyte/macrophage colony-stimulating factor (GM-CSF), interleukin 3 (IL-3), transforming growth factor beta 1 (TGF-beta 1), and tumor necrosis factor alpha (TNF-alpha). However, functional studies with recombinant IL-3, TNF-alpha, and TGF-beta 1 showed that these three factors did not inhibit HIV-1 replication in CEM cells. Neutralization of the PC6-induced HIV-1-inhibiting factor(s) with commercially available neutralizing antibodies to GM-CSF and TNF-alpha also did not abrogate the anti-HIV-1 impact. Thus, the anti-HIV-1 factor induced by PC6 may be novel. Molecular sieve separation showed that the anti-HIV-1 factor(s) is smaller than 30 kDa. Affinity chromatography using a DEAE-cellulose column enriched the factor that inhibited HIV-1.
 ...
PMID:A soluble factor induced by an extract from Pinus parviflora Sieb et Zucc can inhibit the replication of human immunodeficiency virus in vitro. 200 64

Capsid protein (p24;CA) of human immunodeficiency virus type 1 (HIV-1) was synthesized in Escherichia coli strain BL21 (DE3) using a plasmid encoding a truncated HIV-1 gag/pol gene. The plasmid, which contained a mutation in the frameshift region, expressed viral proteinase (PR), a pol gene product, in the gag reading frame, resulting in efficient processing of mature CA and other gag-related products. The expressed CA is soluble, recognized by monoclonal antibodies directed against HIV CA and has an N-terminal sequence identical to that of CA purified from HIV. Purification was done under mild conditions where coexpressed HIV PR retained enzymatic activity. Milligram quantities of 90% pure CA protein were obtained after chromatography on DEAE cellulose followed by facilitated aggregation of the CA in the unbound fraction. The precipitated CA was readily dissolved in low ionic strength aqueous buffer. Gel exclusion chromatography results indicated that, in solution, CA existed in oligomeric form.
 ...
PMID:Expression in Escherichia coli and purification of human immunodeficiency virus type 1 capsid protein (p24). 212 31

A microtransfection method, using either the DEAE-dextran or the Ca.phosphate procedure has been developed. A plasmid expressing the luciferase-encoding gene under the control of the human immunodeficiency virus (HIV) LTR promoter was constructed. Transfections were performed in 96-well plates, allowing statistical evaluation of the results. This microtransfection method requires the use of 100- to 1000-fold less plasmid and cells than in a conventional chloramphenicol acetyl transferase (CAT) assay. A Luciferase index which takes into account cell viability after transfection has been defined using a semi-automated absorbance assay. A 20-h incubation period post-transfection is sufficient for optimal results. Basal long terminal repeat activity and autologous Tat transactivation were studied in various lymphoid, monocytic and adherent human cell lines. Infection of microtransfected cells by HIV activated luc expression. This assay can thus also be used for rapid detection and quantitation of HIV. Antiviral activities of drugs can be assessed in a two-day test.
 ...
PMID:A microtransfection method using the luciferase-encoding reporter gene for the assay of human immunodeficiency virus LTR promoter activity. 218 84

A micromethod for the detection of human immunodeficiency virus (HIV) and other retroviruses in cell culture supernatants is described which applies a DEAE ion exchanger for recovery of polynucleotides synthesized in vitro by the retroviral reverse transcriptase. Cell culture, sample preparation, and test performance including the washing step are adapted to microtitre plates. Compared to the standard method this technique produced less non-specific reactions, resulting in a more than 3-fold higher sensitivity, a higher reproducibility due to lower intrarun variations and allowed an increase in the daily sample accomplishment per person 3- to 4-fold at lower costs per sample.
 ...
PMID:Detection of human immunodeficiency virus and other retroviruses in cell culture supernatants by a reverse transcriptase microassay. 245 27


1 2 3 4 Next >>