Nonproteolyzed Form of DNA-Polymerase ε from T-Cell Spontaneous Lymphoma of Sprague-Dawley Inbred Rat: Isolation and Characterization

1998 ◽  
Vol 63 (5) ◽  
pp. 723-731 ◽  
Author(s):  
Gabriel Birkuš ◽  
Pavel Kramata ◽  
Ivan Votruba ◽  
Berta Otová ◽  
Miroslav Otmar ◽  
...  

Using a simple isolation procedure and selective assay for the determination of enzyme activity the nonproteolyzed and proteolyzed form of DNA-polymerase ε (pol ε and pol ε*) from the lymphoma of Sprague-Dawley inbred rats were purified. Nonproteolyzed pol ε is composed of two subunits (240 000 and 50 000) with sedimentation coefficient 10.5 S, while the subunit composition of pol ε* was 145 000 and 73 000. Estimated Km values for dATP and dGTP as well as Ki values for acyclic nucleotide analogs (PMEApp, HPMPApp and PMEDAPpp) in pol ε and pol ε* catalyzed reactions have shown that a proteolysis probably does not affect pol ε binding site for dNTPs. Both enzymes (pol ε and pol ε*) possess 3'-5'-exonuclease activity with different Km for 3'-OH end of template poly dA-oligo dT18 (1.6 μmol/l and 0.36 μmol/l, respectively).

1995 ◽  
Vol 60 (9) ◽  
pp. 1555-1572 ◽  
Author(s):  
Pavel Kramata ◽  
Jaroslav Černý ◽  
Gabriel Birkuš ◽  
Ivan Votruba ◽  
Berta Otová ◽  
...  

Using a single isolation procedure and selective assays for the determination of enzyme activity, highly purified DNA-polymerases α, δ and ε were isolated from the lymphoma of Sprague-Dawley inbred rats. For pol α the subunit composition was 170, 70, 57 and 53 kDa with sedimentation coefficient 8.7 S for the native molecule; pol delta consists of two polypeptides (133 and 46 kDa; sedimentation coefficient 8.2 S), while pol ε is a single polypeptide (140 kDa) and its sedimentation coefficient is 7.0 S. Comparison of the interaction of individual enzymes with known inhibitors and proliferating cell nuclear antigen (PCNA) using the template-primer poly dA-oligo dT12-18, gave the following data: (i) pol α is selectively inhibited by N2-(p-butylphenyl)-2'-deoxyguanosine 5'-triphosphate (BuPdGTP) and stimulated by dimethyl sulfoxide; (ii) all the enzymes are inhibited by N-ethylmaleimide and aphidicolin; (iii) PCNA stimulates pol δ approximately 50 times while pol ε is moderately inhibited; (iv) pol α exhibits considerably higher DNA-primase activity with poly dC as template than with poly dT, and negligible 3'-5'-exonuclease activity whereas pol δ and pol ε, which do not exert any DNA-primase activity have approximately the same 3'-5'-exonuclease activity. The ability of individual polymerases to utilize poly dT-oligo dA12-18 as a template-primer at different pH values, ionic strengths and Mg2+-concentrations was also investigated. In comparison to poly dA-oligo dT12-18 template-primer, pol α has 140% of enzyme activity on poly dT-oligo dA12-18 under optimal conditions, whereas the activity of pol ε and pol δ is 4 times and 10 times lower, respectively.


Genetics ◽  
1982 ◽  
Vol 100 (1) ◽  
pp. 79-87
Author(s):  
Daniel W Nebert ◽  
Nancy M Jensen ◽  
Hisashi Shinozuka ◽  
Heinz W Kunz ◽  
Thomas J Gill

ABSTRACT Forty-four inbred and four randombred rat strains and 20 inbred mouse strains were examined for their Ah phenotype by determining the induction of liver microsomal aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity (EC 1.14.14.1) by intraperitoneal treatment with either β-naphthoflavone or 3-methylcholanthrene. All 48 rat strains were found to be Ah-responsive. The maximally induced hydroxylase specific activities of the ALB/Pit, MNR/Pit, MR/Pit, SHR/Pit, and Sprague-Dawley strains were of the same order of magnitude as the basal hydroxylase specific activities of the ACI/Pit, F344/Pit, OKA/Pit, and MNR/N strains. Six of the 20 mouse strains were Ah-nonresponsive (i.e. lacking the normal induction response and presumably lacking detectable amounts of the Ah receptor). The basal hydroxylase specific activities of the BDL/N, NFS/N, STAR/N, and ST/JN mouse strains were more than twice as high as the maximally induced hydroxylase specific activity of the CBA/HT strain.——To date, 24 Ah-nonresponsive mouse strains have been identified, out of a total of 68 known to have been characterized. The reasons for not finding a single Ah-nonresponsive inbred rat strain—as compared with about one Ah-nonresponsive inbred mouse strain found for every three examined—remain unknown.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Celosia Lukman ◽  
Christopher Yonathan ◽  
Stella Magdalena ◽  
Diana Elizabeth Waturangi

Abstract Objective This study was conducted to isolate and characterize lytic bacteriophages for pathogenic Escherichia coli from chicken and beef offal, and analyze their capability as biocontrol for several foodborne pathogens. Methods done in this research are bacteriophage isolation, purification, titer determination, application, determination of host range and minimum multiplicity of infection (miMOI), and bacteriophage morphology. Results Six bacteriophages successfully isolated from chicken and beef offal using EPEC and EHEC as host strain. Bacteriophage titers observed between 109 and 1010 PFU mL−1. CS EPEC and BL EHEC bacteriophage showed high efficiency in reduction of EPEC or EHEC contamination in meat about 99.20% and 99.04%. The lowest miMOI was 0.01 showed by CS EPEC bacteriophage. CI EPEC and BL EPEC bacteriophage suspected as Myoviridae family based on its micrograph from Transmission Electron Microscopy (TEM). Refers to their activity, bacteriophages isolated in this study have a great potential to be used as biocontrol against several foodborne pathogens.


Parasitology ◽  
1993 ◽  
Vol 107 (2) ◽  
pp. 135-139 ◽  
Author(s):  
A. Makioka ◽  
B. Stavros ◽  
J. T. Ellis ◽  
A. M. Johnson

SUMMARYA DNA polymerase activity has been detected and characterized in crude extracts from tachzoites of Toxoplasma gondii. The enzyme has a sedimentation coefficient of 6·4 S, corresponding to an approximate molecular weight of 150000 assuming a globular shape. Like mammalian DNA polymerase α, the DNA polymerase of T. gondii was sensitive to N-ethylmaleimide and inhibited by high ionic strength. However, the enzyme activity was not inhibited by aphidicolin which is an inhibitor of mammalian DNA polymerases α, δ and ε and also cytosine-β-D-arabinofuranoside-5′-triphosphate which is an inhibitor of α polymerase. The activity was inhibited by 2′,3′-dideoxythymidine-5′-triphosphate which is an inhibitor of mammalian DNA polymerase β and γ. Magnesium ions (Mg2+) were absolutely required for activity and its optimal concentration was 6 mM. The optimum potassium (K+) concentration was 50 mM and a higher concentration of K+ markedly inhibited the activity. Activity was optimal at pH 8. Monoclonal antibodies against human DNA polymerase did not bind to DNA polymerase of T. gondii. Thus the T. gondii enzyme differs from the human enzymes and may be a useful target for the design of toxoplasmacidal drugs.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Deena Priscilla Henry ◽  
Jasmine Ranjan ◽  
Rajesh Kumar Murugan ◽  
Annapoorani Sivanantham ◽  
Manikandan Alagumuthu

Abstract Background Plant extracts are effectively acting as the natural medicinal cocktail, non-side effective, efficacious, and freely available. The present study aimed to unveil the pharmacological and medicinal effects of Terminalia chebula plant extract in 7,12-dimethylbenzanthracene (DMBA)-induced mammary carcinoma in Sprague Dawley rats. The plant extract obtained was subjected to in vivo antioxidant and anticancer studies in various concentrations after an analytical technique such as FTIR, GCMS, and HPLC-based chemo-profiling in Sprague Dawley rats. Results Apart from the antiproliferative effect on breast cancer cell line (MCF-7) and normal breast epithelial cells (MCF-10a), we have measured the changes in body weight, along with other tumor parameters such as tumor volume, tumor incidence, tumor weight, tumor burden, serum biochemical parameters, and histopathological findings of breast tissue. As the oxidative stress further enhances the development of cancer, the antioxidant property of the plant extract demonstrates its use against cancer treatment. One hundred fifty milligrams per milliliter (IC50 250 μg/mL) concentration of the ethanolic extract was vital for the proliferation of MCF-7 cell lines (Fig. 7a). Meanwhile, 300 μg/mL (IC50 150 μg/mL) was an effective dose to attain a maximum HDAC inhibition of 78%. Also, the normal liver and kidney functioning revealed the non-toxicity nature of the plant. Conclusion Terminalia chebula could be one of the effective naturally obtained anti-breast cancer medications. Isolation and characterization of individual bioactive compounds of T. chebula would be the future perspective.


1991 ◽  
Vol 261 (2) ◽  
pp. H583-H589 ◽  
Author(s):  
E. D. Hendley ◽  
W. G. Ohlsson

Two new strains of inbred rats have been developed. One, WKHA, exhibits hyperactivity, and the other, WKHT, exhibits hypertension. Both of these traits are expressed in the SHR. By crossing spontaneously hypertensive rats (SHRs) with Wistar-Kyoto (WKY) controls, followed by recombinant selected inbreeding, we succeeded in genetically separating the hyperactivity from the hypertension in two new strains. Longitudinal studies indicate a persistence of hypertension without hyperactivity in WKHTs, and hyperactivity without hypertension in WKHAs, over at least 1 year. Ventricular enlargement, another characteristic of SHRs, was observed in adult WKHTs after the onset of hypertension; however, ventricles were already enlarged in normotensive WKHAs at 6 wk. The emergent behavioral profile of WKHAs indicates that they retain the hyperactivity trait and hyperreactivity to stress, and not some of the other behaviors of SHRs, such as poor habituation. Studies in WKHTs suggest that they are an improvement over SHRs as a model of genetic hypertension as they lack some prominent behavioral abnormalities. Nevertheless, the four genetically related strains (WKHA, WKHT, SHR, and WKY), used together, are considered most appropriate for seeking correlations of biological differences with either hypertension or hyperactivity.


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