Search results for "Nuclease activity"
showing 5 items of 5 documents
Alteration of nuclear (2'-5')oligoriboadenylate synthetase and nuclease activities preceding replication of human immunodeficiency virus in H9 cells.
1988
After infection of the respective target cells with the human immunodeficiency virus (HIV-1) viral progeny is produced only after a short temporary delay of some days, depending on cell type. After this period of time a sudden onset of HIV-1 protein synthesis with a dramatic increase in virus release occurs. (2'-5')Oligoriboadenylates [(2'-5')A], capable to activate a latent ribonuclease (RNase L) degrading both mRNA and rRNA, are known mediators involved in the early response of cells to virus infection. Here we show that the (2'-5')A-synthesizing (2'-5')A synthetase, which is inducible by interferon and activated by double-stranded RNA, as well as a (2'-5')A nuclease (2',3'-exoribonucleas…
Deoxyribonuclease activities in human leukemic cells and mouse lymphoblasts
1975
Summary The deoxyribonuclease activities from human lymphocytes have been compared with the activities from acute lymphocytic leukemic cells and mouse leukemic cells L5178Y using the in situ detection of deoxyribonucleases in DNA-containing polyacrylamide gels following their separation by micro-disc-electrophoresis. A neutral deoxyribonuclease activity is completely missing in leukemic cells of untreated patients while a group of acid deoxyribonuclease activities is increased. A similar deoxyribonuclease pattern can be seen in L5178Y cells. Under medical treatment the increment of the acid deoxyribonuclease activities disappears and the neutral deoxyribonuclease activity reappears.
Two copper complexes from two novel naphthalene-sulfonyl-triazole ligands: different nuclearity and different DNA binding and cleavage capabilities.
2013
[EN] Two novel naphthalene-sulfonyl-triazole ligands, 5-amino-N1-(naphthalen-3-ylsulfony1)-1,2,4-triazole (anstrz) and 3,5-diamino-N1-(naphthalen-3-ylsulfony1)-1,2,4-triazole (danstrz), purposely designed to interact with DNA, have been prepared for the first time and then fully characterized by H-1, C-13 NMR and IR spectroscopy, mass spectrometry and elemental analysis. The crystal structures of two copper complexes of these derivatives, i.e. [Cu(anstrz)(4)(NO3)(2)]center dot 4CH(3)OH (1), mononuclear, and [Cu(danstrz)(mu-OAc)(2)](2)center dot 2(danstrz) (OAc = acetato) (2), dinuclear, have been determined by single-crystal X-ray diffraction. In both cases the ligand coordinates in a monod…
Alterations of Activities of Ribonucleases and Polyadenylate Polymerase in Synchronized Mouse L Cells
1977
The activities of the three known catabolic and the one anabolic polyadenylate enzymes have been determined in synchronized L5178y cells: endoribonuclease, exoribonuclease, 5'-nucleotidase and poly(A) polymerase (Mg2+-dependent). These four enzymes were found primarily in the nuclear fraction. The activity of poly(A) polymerase remains essentially constant during the transition from G1 to S phase. However, the poly(A) catabolic enzyme activities increase parallel with DNA synthesis; the endoribonuclease activity increases 4-fold during G1 to S phase, the exoribonuclease and the nucleotidase activities increasing 30-fold and 16-fold. During the S phase the poly(A)-degrading enzymes are far m…
Metazoan Circadian Rhythm: Toward an Understanding of a Light-Based Zeitgeber in Sponges
2013
In all eukaryotes, the 24-h periodicity in the environment contributed to the evolution of the molecular circadian clock. We studied some elements of a postulated circadian clock circuit in the lowest metazoans, the siliceous sponges. First, we identified in the demosponge Suberites domuncula the enzyme luciferase that generates photons. Then (most likely), the photons generated by luciferase are transmitted via the biosilica glass skeleton of the sponges and are finally harvested by cryptochrome in the same individual; hence, cryptochrome is acting as a photosensor. This information-transduction system, generation of light (luciferase), photon transmission (through the siliceous spicules),…