Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An enzyme capable to split adenosine triphosphate (ATP) was shown to be firmly associated with mature herpes simplex virus particles purified from infected rabbit lung (ZP) cells. The enzyme localized in the viral envelope was markedly activated by bivalent cations, to the largest degree by Mg2+ at a pH optimum of 7.8--8.0. Na+ and K+ ions neither separately nor together showed any activating effect. Enzyme activity was not sensitive to the action of ouabain. No adenosine diphosphatase (ADPase) and adenosine monophosphatase (AMPase) activities were observed. ATPase activity was competitively inhibited by ADP. AMP and inorganic phosphate were without effect. The ATPase of nuclear membranes isolated from ZP cells exhibited similar properties but behaved differently to the action of sodium dithionite, dinitrophenol, oligomycin and gramicidin, as well as on heat inactivation. The origin of the virus enzyme is discussed.
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PMID:Some properties of the adenosine triphosphatase associated with herpes simplex virus and nuclear membrane of host cells. 2 4

An enzyme histochemical study of experimental herpes simplex encephalitis of the mouse has revealed a decrease in the number of capillaries displaying alkaline phosphatase activity. Glial cells showed increased Inosine 5 diphosphatase and ATPase activity. These enzyme histochemical changes were distributed throughout the nervous parenchyma while the lesions, seen by light microscopy, are localized to well defined areas. Mice inoculated with a pure culture of irradiated HSV failed to show the above mentioned modifications.
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PMID:Vascular and neuroglial changes in experimental herpes simplex encephalitis enzyme histochemical study. 17 Jul 79

Enveloped and unenveloped forms of herpes simplex virus (HSV) occurring in infected rabbit lung (ZP line) cells were purified by differential and discontinuous Ficoll density gradient centrifugation. Then the viral particles were separated in a sucrose-D2O density gradient. In the course of the procedures, both virus preparations were freed of Mg2+-dependent Na+ plus K+-stimulated adenosine triphosphatase (ATPase), 5'-nucleotidase, and glucose-6-phosphatase activities. However, Mg2+ -activated ATPase was shown to be firmly associated with purified virions. The recovery of infectious virus was 50-60 percent. The specific infectivities (TCID50/mg protein) of the purified enveloped and unenveloped viral particles were 1-2 times 10(10) and 2-5 times 10(6), respectively. The infectivity of the unenveloped viral particles was discussed.
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PMID:Purification and separation of enveloped and unenveloped herpes simplex virus particles. 24 Dec 23

A DNA helicase (delta helicase) which partially copurifies with DNA polymerase delta has been highly purified from fetal calf thymus. delta helicase differs in physical and enzymatic properties from other eukaryotic DNA helicases described thus far. The enzyme has an apparent mass of 57 kDa by gel filtration and is associated with polypeptides of 56 and 52 kDa by SDS-polyacrylamide gel electrophoresis. Photo-cross-linking of the purified enzyme with [alpha-32P]ATP resulted in labeling of a polypeptide of approximately 58 kDa, suggesting that the active site is present on the larger polypeptide. Unwinding of a partial duplex requires a nucleoside triphosphate which can be either ATP or dATP but not a nonhydrolyzable analogue of ATP. Other ribo- and deoxyribonucleoside triphosphates have little or no activity as cofactors. delta helicase also has DNA-dependent ATPase activity which has a relatively low Km for ATP (40 microM). delta helicase binds to single-stranded DNA but has little or no affinity for double-stranded DNA or single-stranded RNA. Similar to replicative DNA helicases from prokaryotes and the herpes simplex virus type 1 helicase-primase, delta helicase translocates in the 5'-3' direction along the strand to which it is bound and preferentially unwinds DNA substrates with a forklike structure.
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PMID:Purification and characterization of delta helicase from fetal calf thymus. 131 98

The herpes simplex virus (HSV) type 1 helicase-primase is a three-protein complex, consisting of a 1:1:1 association of UL5, UL8, and UL52 gene products (J.J. Crute, T. Tsurumi, L. Zhu, S. K. Weller, P. D. Olivo, M. D. Challberg, E. S. Mocarski, and I. R. Lehman, Proc. Natl. Acad. Sci. USA 86:2186-2189, 1989). We have purified this complex, as well as a subcomplex consisting of UL5 and UL52 proteins, from insect cells infected with baculovirus recombinants expressing the appropriate gene products. In confirmation of previous reports, we find that whereas UL5 alone has greatly reduced DNA-dependent ATPase activity, the UL5/UL52 subcomplex retains the activities characteristic of the heterotrimer: DNA-dependent ATPase activity, DNA helicase activity, and the ability to prime DNA synthesis on a poly(dT) template. We also found that the primers made by the subcomplex are equal in length to those synthesized by the UL5/UL8/UL52 complex. In an effort to uncover a role for UL8 in HSV DNA replication, we have developed a model system for lagging-strand synthesis in which the primase activity of the helicase-primase complex is coupled to the activity of the HSV DNA polymerase on ICP8-coated single-stranded M13 DNA. Using this assay, we found that the UL8 subunit of the helicase-primase is critical for the efficient utilization of primers; in the absence of UL8, we detected essentially no elongation of primers despite the fact that the rate of primer synthesis on the same template is undiminished. Reconstitution of lagging-strand synthesis in the presence of UL5/UL52 was achieved by the addition of partially purified UL8. Essentially identical results were obtained when Escherichia coli DNA polymerase I was substituted for the HSV polymerase/UL42 complex. On the basis of these findings, we propose that UL8 acts to increase the efficiency of primer utilization by stabilizing the association between nascent oligoribonucleotide primers and template DNA.
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PMID:The UL8 subunit of the herpes simplex virus helicase-primase complex is required for efficient primer utilization. 132 Dec 75

The UL9 gene of herpes simplex virus encodes a protein that specifically recognizes sequences within the viral origins of replication and exhibits helicase and DNA-dependent ATPase activities. The specific DNA binding domain of the UL9 protein was localized to the carboxy-terminal one-third of the molecule (H. M. Weir, J. M. Calder, and N. D. Stow, Nucleic Acids Res. 17:1409-1425, 1989). The N-terminal two-thirds of the UL9 gene contains six sequence motifs found in all members of a superfamily of DNA and RNA helicases, suggesting that this region may be important for helicase activity of UL9. In this report, we examined the functional significance of these six motifs for the UL9 protein through the introduction of site-specific mutations resulting in single amino acid substitutions of the most highly conserved residues within each motif. An in vivo complementation test was used to study the effect of each mutation on the function of the UL9 protein in viral DNA replication. In this assay, a mutant UL9 protein expressed from a transfected plasmid is used to complement a replication-deficient null mutant in the UL9 gene for the amplification of herpes simplex virus origin-containing plasmids. Mutations in five of the six conserved motifs inactivated the function of the UL9 protein in viral DNA replication, providing direct evidence for the importance of these conserved motifs. Insertion mutants resulting in the introduction of two alanines at 100-residue intervals in regions outside the conserved motifs were also constructed. Three of the insertion mutations were tolerated, whereas the other five abolished UL9 function. These data indicate that other regions of the protein, in addition to the helicase motifs, are important for function in vivo. Several mutations result in instability of the mutant products, presumably because of conformational changes in the protein. Taken together, these results suggest that UL9 is very sensitive to mutations with respect to both structure and function, perhaps reflecting its multifunctional character.
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PMID:The conserved helicase motifs of the herpes simplex virus type 1 origin-binding protein UL9 are important for function. 132 87

A number of agents have been shown to alter the latent state of herpes simplex virus in murine sensory ganglia. However, it seems that effective triggers of recrudescent disease must act not only to reactivate latent HSV infection, but also to create a favorable environment in the skin for viral replication. The possibility that alteration of the local Langerhans cell population is one way in which effective triggers of recrudescence may act has been investigated. Of the agents tested, which affect latent HSV, only DMSO significantly altered the numbers of ATPase-bearing Langerhans cells in the epidermis, maximally reducing their density by 83% in 48 h. Xylene and retinoic acid had no discernible effect on numbers of ATPase-staining cells over the 4 d tested. However, the extent to which agents reduced ATPase-staining cell numbers did not correlate with their ability to affect the antigen-presenting capacity of the cells in HSV-specific T-cell proliferative assays in vitro. Xylene and retinoic acid markedly reduced the accessory cell function of epidermal cell suspensions, whereas DMSO had no effect.
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PMID:Effects on murine epidermal Langerhans cells of drugs known to cause recrudescent herpes simplex virus infection in a mouse model. 165 14

A recombinant herpes simplex 1 origin binding protein, the product of the herpes UL9 gene, has been overexpressed in mammalian cells and purified to near homogeneity. The origin binding protein shows DNA-dependent nucleoside 5'-triphosphatase and DNA helicase activities in addition to its origin binding activity. The ability to hydrolyze nucleoside 5'-triphosphates is influenced strongly by the structure and sequence of the DNA cofactor. The properties of the recombinant origin binding protein are identical to those of the protein synthesized in herpes simplex 1-infected mammalian cells.
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PMID:The herpes simplex virus 1 origin binding protein: a DNA helicase. 184 32

Herpes simplex virus 1 encodes a helicase-primase that is composed of the products of the UL5, UL8, and UL52 genes. A stable subassembly consisting of only the UL5 and UL52 gene products has been purified to near homogeneity from insect cells doubly infected with baculovirus recombinant for these two genes. The purified subassembly has the DNA-dependent ATPase, DNA-dependent GTPase, DNA helicase, and DNA primase activities that are characteristic of the three-subunit holoenzyme. The purified UL8 gene product, although required for viral DNA replication, neither exhibits these enzymatic activities nor stably associates with either the UL5 or the UL52 gene product.
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PMID:Association of DNA helicase and primase activities with a subassembly of the herpes simplex virus 1 helicase-primase composed of the UL5 and UL52 gene products. 184 9

Urocanic acid (UCA) is found in the stratum corneum predominantly as the trans-isomer; on ultraviolet B (UVB) irradiation, isomerization to the cis-isomer occurs. Cis-UCA has been shown to mimic the consequences of UVB irradiation in generating transient suppression of contact and delayed hypersensitivity (DH) responses. In an attempt to elucidate the mechanisms of action of UCA, the effects of 2 histamine receptor antagonists, cimetidine and terfenadine, were examined. One day after skin painting murine ears with cis-UCA, the number of ATPase- cells was reduced from 1068 to 408 mm-2. However, if cimetidine or terfenadine was applied at the same time as cis-UCA, the number of ATPase- cells was reduced only slightly from the control value, to 1028 and 892 respectively. Cis-UCA given subcutaneously or epidermally 5 h before infection of mice with herpes simplex virus suppressed the DH response on subsequent challenge with the virus. If cimetidine or terfenadine was added at the same time as cis-UCA, little suppression of the DH response to the virus occurred. Thus 2 effects of cis-UCA, on the number of ATPase+ epidermal cells and on DH response, were reduced or abrogated by histamine receptor antagonists, which may indicate that cis-UCA acts through histamine-like receptors in the skin.
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PMID:The effect of histamine receptor antagonists on immunosuppression induced by the cis-isomer of urocanic acid. 198 93


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