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 human serum albumin gene was analyzed by restriction endonuclease mapping of chromosomal DNA isolated from a patient with congenital analbuminemia. Following digestion with a variety of restriction endonucleases, the DNA from this individual produced the same fragments with homology to a serum albumin cDNA probe as did a control DNA specimen. Therefore, the genetic condition of congenital analbuminemia is not caused by any gross structural rearrangement or deletion of the gene itself, but may result from an abnormality in the gene's fine structure, perhaps affecting regulation or processing of the primary RNA transcript.
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PMID:Structural integrity of the human albumin gene in congenital analbuminemia. 631 71

A quantitative endonuclease assay, which relies on the introduction of single and double strand breaks into supercoiled plasmid DNA, was used to study the activity of the extracellular nuclease of Serratia marcescens SM6 in buffer and in groundwater. The parallel enzyme concentration-dependent production of relaxed and linear plasmid molecules suggests that the nuclease produces single and double strand breaks in duplex DNA. Bovine serum albumin stimulated the nuclease activity towards DNA and RNA and increased the stability of the enzyme against thermal inactivation. The DNase activity at 4 degrees C and 50 degrees C was almost half of that at the optimum temperature (37 degrees C). The nuclease was active in groundwater, although the specific activity was lower than in buffer. In a groundwater aquifer microcosm, mineral-adsorbed transforming DNA was substantially less accessible to the nuclease than was dissolved DNA. The data suggest that the extracellular nuclease of Serratia marcescens may contribute to DNA turnover in the environment and that adsorption of DNA to minerals provides protection against the nuclease.
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PMID:The extracellular nuclease of Serratia marcescens: studies on the activity in vitro and effect on transforming DNA in a groundwater aquifer microcosm. 814 44

Estrogen-mediated accumulation of the avian apolipoprotein (apo) II mRNA is in part due to its stabilization. To identify the biochemical activity responsible for this effect, radiolabeled, capped, and polyadenylated apoII mRNA was incubated in vitro in liver cytosolic extracts from roosters who received either estrogen (estrogen-treated extract) or the vehicle (control extract) parenterally. The mRNA was very stable in estrogen-treated extract but was rapidly degraded in control extract. The RNA was degraded predominantly by endonuclease rather than exonuclease activity. The addition of the estrogen-treated extract to the control extract prevented the degradation of the mRNA in trans. This biochemical activity was heat labile and was also destroyed by proteinase K but not by micrococcal nuclease, indicating that estrogen treatment resulted in the expression of a protein in the liver that stabilized the apoII mRNA by inhibiting its nucleolytic degradation. This mRNA stabilization factor was labile around 60 degrees C, whereas the RNase remained stable up to 80 degrees C. Studies on mRNA protein interaction showed that both control and estrogen-treated extracts contain mRNA-binding (mRNP) proteins that bind apoII mRNA. An increased binding to apoII mRNA by a subset of these proteins was observed with estrogen-treated extract as compared with the control extract. This activity, although it afforded complete protection from nucleolytic degradation to apoII and apo A1 mRNAs, appeared to provide less protection to mRNAs encoding chicken serum albumin and vitellogenin, suggesting differential stabilization of mRNAs. These studies indicate that a cytosolic mRNA-stabilization factor, providing apoII mRNA complete protection from nucleolytic degradation, is expressed in the avian liver upon estrogen treatment. This appears to be the first time that a biochemical activity responsible for hormone-mediated stabilization of mRNAs and estrogen induction of mRNA binding by specific mRNPs have been identified and partially characterized in vitro.
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PMID:In vitro characterization of an estrogen-regulated mRNA stabilizing activity in the avian liver. 877 38

Experiments undertaken with commercially available recombinantly produced human immunodeficiency virus Type 1 (HIV-1) gp120 demonstrated that the resuspended lyophilized protein, a product of the baculovirus expression system, had intrinsic nuclease activity. This nuclease activity was distinguishable from the molecular-grade bovine serum albumin that it was constituted in. The activity was thermolabile in that if the preparation was heated to 100 degrees C for 10 min, the activity was abolished, although this did not happen when it was stored at -20 degrees C. The nuclease activity was also Ca+2- and Mg+2-dependent, and had endonuclease as opposed to exonuclease activity. Zn+2 ions were found to inhibit the enzyme. The intensity of nuclease activity varied from batch to batch. A lyophilized homogenate of Sf9 insect cells expressing the Rho baculovirus-derived red blood cell protein 4.2 (Pallidin) was also found to have nuclease activity on reconstitution. In contrast, most, though not all E. coli-produced recombinant proteins were found to be free of nuclease activity. The use of activity gels to identify the size of the nuclease contained in the gp120 preparation was limited, because despite the use of many renaturation methods, the enzyme in the gp120 preparation could not be functionally resuscitated following sodium dodecyl sulfate polyacrylamide gel electrophoresis. Immunoprecipitation studies were useful to demonstrate that nuclease activity in the gp120 preparation was functionally distinguishable from the gp120 itself. When mononuclear cells transformed with anti-CD3 were concurrently incubated with gp120 (5-40 micrograms/mL), internucleosomal DNA fragments characteristic of apoptosis were demonstrated in the supernatant by DNA gel electrophoresis. In the context of HIV-1 and AIDS, where the depletion of CD4+ T-cells has been found to be associated with apoptosis, nuclease activity intrinsic to the gp120 preparation used in experimentation may potentially alter experimental results.
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PMID:Identification of endonuclease activity in HIV-1 gp120 preparations produced using baculovirus expression systems. 926 86

Our previous study demonstrated that an antibody against single-stranded DNA could detect apoptotic cells [Naruse et al. (1994) Histochemistry 101, 73-78]. In this paper we describe the development of an improved method for the production of the antibody and investigations into the antigenic determinants of the antibody so that it could be of practical use for detecting apoptotic cells. Rabbits, hyperimmunized with complexes of alkaline-denatured calf thymus DNA and methylated bovine serum albumin, produced an IgG antibody to single-stranded DNA. Analysis by sandwich ELISA using various naturally occurring nucleic acids revealed that the antibody was specific to single-stranded DNA. Furthermore, using synthetic polymers in the assay, it was found that the antibody could recognize single-stranded DNA with various base sequences. Gel electrophoresis retardation assays, with synthetic oligodeoxynucleotides with differing lengths of single-stranded DNA, indicated that a hexadeoxynucleotide constituted the minimum size of the antigenic determinants, and suggested that the antibody probably consists of several antibodies which recognize hexadeoxynucleotides with various base sequences. Western blot analysis demonstrated that the antibody can recognize both a DNA ladder and oligonucleosomes prepared from rat liver nuclei with endogenous endonuclease. The present findings demonstrate that this antibody is a useful tool for detecting apoptotic cells.
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PMID:Antibody against single-stranded DNA useful for detecting apoptotic cells recognizes hexadeoxynucleotides with various base sequences. 953 33

The processing of abasic site DNA damage lesions in extracellular DNA in the presence of engineered carbon nanomaterials (CNMs) is demonstrated. The efficacy of the apurinic-apyrimidinic endonuclease 1 (APE1) in the cleavage of abasic site lesions in the presence of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and graphene oxide (GO) are compared. The CNMs were found to perturb the incision activity of APE1. The reason for such perturbation process was anticipated to take place either by the non-specific adsorption of APE1 over the free surface of the CNMs or steric hindrance offered by the CNM-DNA complex. Accordingly, bovine serum albumin (BSA) was selectively utilized to block the free surface of the CNM-DNA hybrid material. Further treatment of the CNM-DNA-BSA complex with APE1 resulted in a marginal increase in APE1 efficiency. This indicates that APE1 in solution is unable to process the abasic sites on DNA adsorbed over the CNMs. However, the cleavage activity of APE1 was restored in the presence of non-ionic surfactant (Tween 20) that inhibits adsorption of the DNA on the surface of the CNMs. The conformational deformation of the DNA, along with steric hindrance induced by the CNMs resulted in the inhibition of abasic site DNA repair by APE1. Moreover, appreciable changes in the secondary structure of APE1 adsorbed over the CNMs were observed that contribute further to the repair refractivity of the abasic sites. From a toxicological viewpoint, these findings can be extended to the study of the effect of engineered nanoparticles in the intracellular DNA repair process.
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PMID:Impeded repair of abasic site damaged lesions in DNA adsorbed over functionalized multiwalled carbon nanotube and graphene oxide. 2726 79


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