Search results for "Endonucleases"

Identification and typing of food-borne Staphylococcus aureus by PCR-based techniques.

2005

Abstract The possibility of using PCR for rapid identification of food-borne Staphylococcus aureus isolates was evaluated as an alternative to the API-Staph system. A total of 158 strains, 15 S. aureus , 12 other staphylococcal species, and 131 isolates recovered from 164 food samples were studied. They were phenotypically characterized by API-Staph profiles and tested for PCR amplification with specific primers directed to thermonuclease ( nuc ) and enterotoxin ( sea to see ) genes. Disagreement between the PCR results and API-Staph identification was further assessed by the analysis of randomly amplified polymorphic DNA (RAPD) profiles obtained with three universal primers (M13, T3, and T…

Endoribonuclease IV. A poly(A)-specific ribonuclease from chick oviduct. 1. Purification of the enzyme.

1976

A new endoribonuclease, termed endoribonuclease IV, has been described. This enzyme has been isolated from chick oviducts and purified 15 000-fold in a 25% yield nearly to homogeneity. The nuclease, which specifically degrades poly(A), forms oligonucleotides of an average chain length of 10. These (A)-10 fragments are terminated by 3'-hydroxyl and 5'-phosphate groups. The enzyme has a pH optimum at 8.7, requires Mn2+ or Mg2+ as a cofactor, and has a molecular weight of about 45 000.

Control of Enzymic Hydrolysis of Polyadenylate Segment of Messenger RNA: Role of Polyadenylate-Associated Proteins

1978

The role of poly(A)-associated proteins in the breakdown of poly(A) sequences in both mammalian polyribosomes and in isolated poly(A) · protein complexes has been studied on an enzymic level. Two nucleases (alkaline exoribonuclease and endoribonuclease IV; both isolated from eukaryotic tissue), which preferentially hydrolyze poly(A) sequences, have been applied to determine the susceptibility of poly(A) in dependence on the presence of poly(A) · protein(s). Polysomes, isolated from L5178y mouse lymphoma cells, do not contain endogenous poly(A) nuclease activity. The poly(A) segment in polysomes is hydrolyzed by the exoribonuclease, irrespective of the preincubation conditions used. Pretreat…

DNA Computing: Concepts for Medical Applications

2022

The branch of informatics that deals with construction and operation of computers built of DNA, is one of the research directions which investigates issues related to the use of DNA as hardware and software. This concept assumes the use of DNA computers due to their biological origin mainly for intelligent, personalized and targeted diagnostics frequently related to therapy. Important elements of this concept are (1) the retrieval of unique DNA sequences using machine learning methods and, based on the results of this process, (2) the construction/design of smart diagnostic biochip projects. The authors of this paper propose a new concept of designing diagnostic biochips, the key elements o…

Gene Repair of an Usher Syndrome Causing Mutation by Zinc-Finger Nuclease Mediated Homologous Recombination

2012

PURPOSE. Human Usher syndrome (USH) is the most frequent cause of inherited deaf-blindness. It is clinically and genetically heterogeneous, assigned to three clinical types of which the most severe type is USH1. No effective treatment for the ophthalmic component of USH exists. Gene augmentation is an attractive strategy for hereditary retinal diseases. However, several USH genes, like USH1C, are expressed in various isoforms, hampering gene augmentation. As an alternative treatment strategy, we applied the zinc-finger nuclease (ZFN) technology for targeted gene repair of an USH1C, causing mutation by homologous recombination. METHODS. We designed ZFNs customized for the p.R31X nonsense mut…

Oxidative DNA base damage induced by singlet oxygen and photosensitization: recognition by repair endonucleases and mutagenicity.

2000

We have analyzed the recognition by various repair endonucleases of DNA base modifications induced by three oxidants, viz. [4-(tert-butyldioxycarbonyl)benzyl]triethylammonium chloride (BCBT), a photochemical source of tert-butoxyl radicals, disodium salt of 1,4-etheno-2,3-benzodioxin-1,4-dipropanoic acid (NDPO(2)), a chemical source of singlet oxygen, and riboflavin, a type-I photosensitizer. The base modifications induced by BCBT, which were previously shown to be mostly 7,8-dihydro-8-oxoguanine (8-oxoGua) residues, were recognized by Fpg and Ogg1 proteins, but not by endonuclease IIII, Ntg1 and Ntg2 proteins. In the case of singlet oxygen induced damage, 8-oxoGua accounted for only 35% of…

Oxidative DNA damage induced by visible light in mammalian cells: extent, inhibition by antioxidants and genotoxic effects

1998

The extent of the indirect DNA damage generated in mammalian cells by visible light because of the presence of endogenous photosensitizers was studied by means of repair endonucleases. In immortalized human keratinocytes (HaCaT cells) exposed to low doses of natural sunlight, the yield of oxidative DNA base modifications sensitive to the repair endonuclease formamidopyrimidine-DNA glycosylase (Fpg protein) generated by this indirect mechanism was 10% of that of pyrimidine dimers (generated by direct DNA excitation). A similar yield of Fpg-sensitive modifications, which include 8-hydroxyguanine, was observed in primary keratinocytes. The relative yield of oxidative base modifications decreas…

Cell cycle-dependent alterations of the two types of ribonucleases H in L5178y cells.

1980

Sequence of a novel cytochrome CYP2B cDNA coding for a protein which is expressed in a sebaceous gland, but not in the liver

1992

The major phenobarbital-inducible rat hepatic cytochromes P-450, CYP2B1 and CYP2B2, are the paradigmatic members of a cytochrome P-450 gene subfamily that contains at least seven additional members. Specific oligonucleotide probes for these genomic members of the CYP2B subfamily were used to assess their tissue-specific expression. In Northern-blot analysis a probe specific to gene 4 (which is designated now as CYP2B12) hybridized to a single mRNA present in the preputial gland, an organ which is used as a model for sebaceous glands, but did not hybridize to mRNA isolated from the liver or from five other tissues of untreated or Aroclor 1254-treated rats. The cDNA sequence for the CYP2B12 R…

Excision repair cross-complementation group 1 protein overexpression as a predictor of poor survival for high-grade serous ovarian adenocarcinoma.

2010

Abstract Objective The excision repair cross-complementation group 1 (ERCC1) expression is a predictor of survival after surgical treatment for several malignancies. Its overexpression has been reported as a marker of platinum resistance in lung cancer. However, the relevance of ERCC1 expression in ovarian cancer (OC) is the subject of controversy, both as a predictive parameter for platinum resistance and because of its association with poor prognosis. Therefore, we performed a retrospective study investigating ERCC1 expression and its correlation with patients' survival in OC. Methods We analyzed the ERCC1 protein expression using four different ERCC1 antibodies (clone 8F1) with different…