scholarly journals The activity of deoxyribonucleic acid polymerase in some species of algae

1972 ◽  
Vol 129 (2) ◽  
pp. 285-290 ◽  
Author(s):  
O. Th. Schönherr ◽  
H. M. Keir
Keyword(s):  
Dna Polymerase ◽  
Green Algae ◽  
Dna Polymerases ◽  
Deae Cellulose ◽  
Chlorella Pyrenoidosa ◽  
Nuclease Activity ◽  
Polymerase Activity ◽  
Ph Optimum ◽  
Blue Green Algae ◽  
Wide Range

1. The activities of DNA polymerase preparations from the algae Euglena gracilis, Chlamydomonas reinhardtii, Chlorella pyrenoidosa, Anabaena variabilis and Anacystis nidulans were measured. The blue–green algae Anabaena and Anacystis contain a 5–20-fold higher activity of the enzyme than do the green algae. DNA polymerases from the blue–green algae show a pH optimum of 9 and prefer a relatively low Mg2+concentration (1–3mm). DNA polymerases from the green algae, however, display a pH optimum between 7.5 and 8.5 and an optimum Mg2+concentration of 8mm. With all algae, a higher polymerase activity was obtained with denatured salmon sperm DNA as template than with native DNA. All four deoxyribonucleoside 5′-triphosphates must be present for full activity of the polymerases. 2. With one exception, the deoxyribonuclease activities in the preparations, measured under conditions of the DNA polymerase assay, are low compared with corresponding preparations from Escherichia coli. Chlamydomonas extracts contain a high deoxyribonuclease activity. 3. After purification on columns of DEAE-cellulose, the polymerase activity was linear over a wide range of protein concentrations, except for Chlamydomonas preparations, where the observed deviation from linearity was probably attributable to the high nuclease activity. 4. DNA polymerases from all these algae bind strongly to DNA–cellulose; 6–40-fold purifications of the enzyme were obtained by chromatography on columns of DNA–cellulose. 5. The partially purified polymerases of Euglena and Anacystis are heat-labile but become much more heat-stable when tested in the presence of DNA.

Inhibition by Cyclic Guanosine 3':5'-Monophosphate of the Soluble DNA Polymerase Activity, and of Partially Purified DNA Polymerase A (DNA Polymerase I) from the Yeast Saccharomyces cerevisiae

1981 ◽  
Vol 36 (9-10) ◽  
pp. 813-819 ◽  
Author(s):  
Hans Eckstein
Keyword(s):  
Dna Polymerase ◽  
Dna Polymerases ◽  
Nuclease Activity ◽  
Polymerase Activity ◽  
Yeast Cells ◽  
Primer Binding Site ◽  
Dna Polymerase I ◽  
Yeast Saccharomyces Cerevisiae ◽  
Main Component ◽  
Polymerase I

Abstract Dedicated to Professor Dr. Joachim Kühnau on the Occasion of His 80th Birthday cGMP, DNA Polymerase Activity, DNA Polymerase A, DNA Polymerase I, Baker's Yeast DNA polymerase activity from extracts of growing yeast cells is inhibited by cGMP. Experiments with partially purified yeast DNA polymerases show, that cGMP inhibits DNA polymerase A (DNA polymerase I from Chang), which is the main component of the soluble DNA polymerase activity in yeast extracts, by competing for the enzyme with the primer-template DNA. Since the enzyme is not only inhibited by 3',5'-cGMP, but also by 3',5'-cAMP, the 3': 5'-phosphodiester seems to be crucial for the competition between cGMP and primer. This would be inconsistent with the concept of a 3'-OH primer binding site in the enzyme. The existence of such a site in the yeast DNA polymerase A is indicated from studies with various purine nucleoside monophosphates.When various DNA polymerases are compared, inhibition by cGMP seems to be restricted to those enzymes, which are involved in DNA replication. DNA polymerases with an associated nuclease activity are not inhibited, DNA polymerase B from yeast is even activated by cGMP. Though some relations between the cGMP effect and the presumed function of the enzymes in the living cell are apparent, the biological meaning of the observations in general remains open.

Detection and characterization of DNA polymerase activity in Toxoplasma gondii

Parasitology ◽  
1993 ◽  
Vol 107 (2) ◽  
pp. 135-139 ◽  
Author(s):  
A. Makioka ◽  
B. Stavros ◽  
J. T. Ellis ◽  
A. M. Johnson
Keyword(s):  
Toxoplasma Gondii ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Sedimentation Coefficient ◽  
Polymerase Activity ◽  
Magnesium Ions ◽  
Dna Polymerase Β ◽  
Human Dna ◽  
Approximate Molecular Weight

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.

scholarly journals Amino Acid Changes within Conserved Region III of the Herpes Simplex Virus and Human Cytomegalovirus DNA Polymerases Confer Resistance to 4-Oxo-Dihydroquinolines, a Novel Class of Herpesvirus Antiviral Agents

2003 ◽  
Vol 77 (3) ◽  
pp. 1868-1876 ◽  
Author(s):  
Darrell R. Thomsen ◽  
Nancee L. Oien ◽  
Todd A. Hopkins ◽  
Mary L. Knechtel ◽  
Roger J. Brideau ◽  
...  
Keyword(s):  
Amino Acid ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Nucleoside Analogs ◽  
Polymerase Activity ◽  
Conserved Domain ◽  
Domain Iii ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT The 4-oxo-dihydroquinolines (PNU-182171 and PNU-183792) are nonnucleoside inhibitors of herpesvirus polymerases (R. J. Brideau et al., Antiviral Res. 54:19-28, 2002; N. L. Oien et al., Antimicrob. Agents Chemother. 46:724-730, 2002). In cell culture these compounds inhibit herpes simplex virus type 1 (HSV-1), HSV-2, human cytomegalovirus (HCMV), varicella-zoster virus (VZV), and human herpesvirus 8 (HHV-8) replication. HSV-1 and HSV-2 mutants resistant to these drugs were isolated and the resistance mutation was mapped to the DNA polymerase gene. Drug resistance correlated with a point mutation in conserved domain III that resulted in a V823A change in the HSV-1 or the equivalent amino acid in the HSV-2 DNA polymerase. Resistance of HCMV was also found to correlate with amino acid changes in conserved domain III (V823A+V824L). V823 is conserved in the DNA polymerases of six (HSV-1, HSV-2, HCMV, VZV, Epstein-Barr virus, and HHV-8) of the eight human herpesviruses; the HHV-6 and HHV-7 polymerases contain an alanine at this amino acid. In vitro polymerase assays demonstrated that HSV-1, HSV-2, HCMV, VZV, and HHV-8 polymerases were inhibited by PNU-183792, whereas the HHV-6 polymerase was not. Changing this amino acid from valine to alanine in the HSV-1, HCMV, and HHV-8 polymerases alters the polymerase activity so that it is less sensitive to drug inhibition. In contrast, changing the equivalent amino acid in the HHV-6 polymerase from alanine to valine alters polymerase activity so that PNU-183792 inhibits this enzyme. The HSV-1, HSV-2, and HCMV drug-resistant mutants were not altered in their susceptibilities to nucleoside analogs; in fact, some of the mutants were hypersensitive to several of the drugs. These results support a mechanism where PNU-183792 inhibits herpesviruses by interacting with a binding determinant on the viral DNA polymerase that is less important for the binding of nucleoside analogs and deoxynucleoside triphosphates.

Preparation of an antibody against a maize DNA polymerase holoenzyme: identification of the polymerase catalytic subunit

1994 ◽  
Vol 72 (6) ◽  
pp. 818-822 ◽  
Author(s):  
P. Coello-Coutiño ◽  
E. García-Ramírez ◽  
J. M. Vázquez-Ramos
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Molecular Mass ◽  
Key Words ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Deae Cellulose ◽  
Key Words Dna ◽  
Embryo Axes ◽  
Maize Embryo

Three different DNA polymerase activities can be separated from germinating maize axes through DEAE – cellulose chromatography. Of these, DNA polymerase 2 appears to be a replicative-type enzyme composed of several subunits. An antibody has been developed against the DNA polymerase 2 multisubunit complex, which mainly recognizes a polypeptide of molecular weight around 90 kDa. Polypeptides of molecular mass of 83, 70, 60, 55, 45, and 24 kDa are also recognized. Activity gels showed that the 90-kDa polypeptide possesses catalytic activity. DNA polymerases 1 and 3 are not recognized by the antibody and their activities are not reduced. However, DNA polymerase 2 activity is reduced by 70%. The nature of the different DNA polymerase accompanying subunits is discussed. Key words: DNA polymerases, maize embryo axes.

scholarly journals Biosynthesis of phytoquinones. Homogentisic acid: a precursor of plastoquinones, tocopherols and α-tocopherolquinone in higher plants, green algae and blue–green algae

1970 ◽  
Vol 117 (3) ◽  
pp. 593-600 ◽  
Author(s):  
G. R. Whistance ◽  
D. R. Threlfall
Keyword(s):  
Green Algae ◽  
Phenylacetic Acid ◽  
Higher Plants ◽  
Chlorella Pyrenoidosa ◽  
Homogentisic Acid ◽  
Side Chain ◽  
Methyl Groups ◽  
Blue Green Algae ◽  
Hydroxyphenylacetic Acid ◽  
Tracer Experiments

1. By means of 14C tracer experiments and isotope competition experiments the roles of d-tyrosine, p-hydroxyphenylpyruvic acid, p-hydroxyphenylacetic acid, phenylacetic acid, homogentisic acid and homoarbutin (2-methylquinol 4-β-d-glucoside) in the biosynthesis of plastoquinones, tocopherols and α-tocopherolquinone by maize shoots was investigated. It was established that d-tyrosine, p-hydroxyphenylpyruvic acid and homogentisic acid can all be utilized for this purpose, whereas p-hydroxyphenylacetic acid, phenylacetic acid and homoarbutin cannot. Studies on the mode of incorporation of d-tyrosine, p-hydroxyphenylpyruvic acid and homogentisic acid showed that their nuclear carbon atoms and the side-chain carbon atom adjacent to the nucleus give rise (as a C6-C1 unit) to the p-benzoquinone rings and nuclear methyl groups (one in each case) of plastoquinone-9 and α-tocopherolquinone and the aromatic nuclei and nuclear methyl groups (one in each case) of γ-tocopherol and α-tocopherol. 2. By using [14C]-homogentisic acid it has been shown that homogentisic acid is also a precursor of plastoquinone, tocopherols and α-tocopherolquinone in the higher plants Lactuca sativa and Rumex sanguineus, the green algae Chlorella pyrenoidosa and Euglena gracilis and the blue–green alga Anacystis nidulans.

Terminal deoxyribonucleotidyltransferase from nuclei of rat intestinal mucosa

1970 ◽  
Vol 48 (5) ◽  
pp. 537-540 ◽  
Author(s):  
F. Y. T. Leung ◽  
S. H. Zbarsky
Keyword(s):  
Dna Polymerase ◽  
Snake Venom ◽  
Intestinal Mucosa ◽  
Deae Cellulose ◽  
Nuclear Extract ◽  
Polymerase Activity ◽  
Snake Venom Phosphodiesterase ◽  
Deoxyribonucleoside Triphosphate

A terminal deoxyribonucleotidyltransferase has been isolated from extracts of nuclei of rat intestinal mucosa. The enzyme was obtained in partially purified form by rechromatography of material with DNA polymerase activity isolated previously by chromatography of the nuclear extract on DEAE-cellulose. The enzyme, which required heat-denatured DNA as a primer, catalyzed the incorporation of radioactivity from a single labelled deoxyribonucleoside triphosphate into the DNA product. The incorporation was inhibited up to 70% in the presence of all four complementary deoxyribonucleoside triphosphates. Evidence has been presented based on the release of radioactivity from the DNA product during its hydrolysis by snake venom phosphodiesterase which indicates that the enzyme catalyzes the addition of deoxyribonucleotides to the 3′-OH terminus of heat-denatured DNA. The properties of the enzyme are those of a terminal deoxyribonucleotidyltransferase as distinct from the replicative transferase, DNA polymerase.

scholarly journals Drinking Water Supply under the Conditions of Mass Development of Blue-green Algae in Reservoirs.

2021 ◽  
pp. 121-134
Author(s):  
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Green Algae ◽  
Rapid Development ◽  
Drinking Water Treatment ◽  
Toxic Substances ◽  
Surface Source ◽  
Blue Green Algae ◽  
Wide Range ◽  
Mass Development

An assessment of the pollution of a surface source of water supply (the Kuibyshev reservoir) with metabolites of cyanobacteria (blue-green algae) under conditions of an increase in biogenic load is carried out. During the period of mass development of cyanobacteria, the quality of water in the reservoir deteriorates in terms of a number of indicators, including smell, taste, and content of organic and toxic substances. Among the wide range of cyanoxins, the greatest danger to the population is microcystin-LR, the concentration of which in drinking water should not exceed 1 μg/dm3. The growth of anthropogenic load and global warming of the climate create favorable conditions for the rapid development of cyanobacteria, therefore, the problem of providing the population with high-quality drinking water will only worsen in the future. Traditional methods used at drinking water treatment plants in Volga cities are ineffective in removing intracellular and extracellular cyanotoxins. The best and safest barrier against the ingress of cyanotoxins into drinking water can be membrane technologies that allow ultrafiltration of bacterial cells without mechanical damage and nanofiltration of cyanotoxins dissolved in water.

scholarly journals Polymerization activity of an alpha-like DNA polymerase requires a conserved 3'-5' exonuclease active site

1991 ◽  
Vol 11 (9) ◽  
pp. 4786-4795
Author(s):  
J S Gibbs ◽  
K Weisshart ◽  
P Digard ◽  
A deBruynKops ◽  
D M Knipe ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Active Site ◽  
Dna Polymerases ◽  
Polymerase Activity ◽  
Cell Nuclei ◽  
Dna Polymerase I ◽  
Viral Dna ◽  
Gene Encoding ◽  
Simplex Virus ◽  
Polymerase I

Most DNA polymerases are multifunctional proteins that possess both polymerizing and exonucleolytic activities. For Escherichia coli DNA polymerase I and its relatives, polymerase and exonuclease activities reside on distinct, separable domains of the same polypeptide. The catalytic subunits of the alpha-like DNA polymerase family share regions of sequence homology with the 3'-5' exonuclease active site of DNA polymerase I; in certain alpha-like DNA polymerases, these regions of homology have been shown to be important for exonuclease activity. This finding has led to the hypothesis that alpha-like DNA polymerases also contain a distinct 3'-5' exonuclease domain. We have introduced conservative substitutions into a 3'-5' exonuclease active site homology in the gene encoding herpes simplex virus DNA polymerase, an alpha-like polymerase. Two mutants were severely impaired for viral DNA replication and polymerase activity. The mutants were not detectably affected in the ability of the polymerase to interact with its accessory protein, UL42, or to colocalize in infected cell nuclei with the major viral DNA-binding protein, ICP8, suggesting that the mutation did not exert global effects on protein folding. The results raise the possibility that there is a fundamental difference between alpha-like DNA polymerases and E. coli DNA polymerase I, with less distinction between 3'-5' exonuclease and polymerase functions in alpha-like DNA polymerases.

scholarly journals DNA-metabolizing enzymes in normal human lymphoid cells. VI. Induction of DNA polymerases alpha, beta, and gamma following stimulation with phytohemagglutinin

Blood ◽  
1975 ◽  
Vol 46 (4) ◽  
pp. 509-518
Author(s):  
RJ Mayer ◽  
RG Smith ◽  
RC Gallo
Keyword(s):  
Dna Polymerase ◽  
Mammalian Cells ◽  
Dna Polymerases ◽  
Polymerase Activity ◽  
Lymphoid Cells ◽  
Blood Lymphocytes ◽  
Polymerase Beta ◽  
Normal Human ◽  
Alpha Beta ◽  
Cellular Dna

At least three distinct DNA polymerases, named alpha, beta, and gamma, have been isolated from normal mammalian cells. The function of these enzymes in regard to DNA replication and repair remains unclear. Stimulation of blood lymphocytes with the plant mitogen phytohemagglutinin (PHA), is known to increase total DNA polymerase activity. In this study, we measured the change of each of these activities as lymphocytes intered a mitotic cycle. Aliquots of a pool of normal human blood lymphocytes were incubated with PHA for 0, 24, 48, and 72 hr, respectively, and the various DNA polymerase activities quantitated at each point. No significant DNA polymerase activity was detected in unstimulated cells. Low levels of polymerase beta were found at 24 hr. The average DNA content per cell doubled between 24 and 48 hr, and during this interval all three DNA polymerases increased to easily detectable levels. By far the greatest fractional increase in activity of all three polymerases was seen between 48 and 72 hr, after the average doubling of cellular DNA. In summary, these blood lymphocytes lack significant levels of DNA polymerases; stimulation with PHA induces all three of the major DNA polymerase species. In both these respects, these cells differ from other proliferating mammalian cell systems. The possible significance of this difference is discussed.

scholarly journals Comparative Growth Rate of Cyanobacteria from “Usar” Soil (saline/alkaline soils) with Respect to Pigments

2021 ◽  
Vol 9 (4) ◽  
pp. 129-135
Author(s):  
Vivek Kumar Yadav ◽  
◽  
Keyword(s):  
Green Algae ◽  
Uttar Pradesh ◽  
Alkaline Soils ◽  
Blue Green Algae ◽  
Wide Range ◽  
Anabaena Sp ◽  
Extraction Solvents ◽  
Pigment Variation ◽  
Layer Chromatography ◽  
Saline Alkaline Soils

The pigment content in Blue-green algae is a specific feature of each species. The pigment variation is specific features among microalgae. The paper aim to analyze cyanobacterial extracts of different Usar soil of Azamgarh and Varanasi, Uttar Pradesh. The main object here is the importance of the blue green algae especially because of the pigments present in this class of algae. Pigments from natural sources are gaining more importance mainly due to health and environmental issues. Algae contain a wide range of pigments. Three major classes of pigments are chlorophylls, carotenoids (carotenes and xanthophylls) and phycobilins (Phycocyanin and phycoerythrin). Our present study investigates the efficiency for phycobiliprotein pigment production from four different cyanobacteria Hapalosiphon sp., Phormidium sp., Anabaena sp. and Nostoc sp. The harvested and dried biomass was subjected to extract pigments using different solvents. Thin Layer Chromatography was performed from extracted pigments using Acetone as extraction solvents. And running solvent especially for phycocyanin pigment was optimized and concluded that Petroleum ether and Acetone in the ratio of 7:3. This paper presents the information about the natural pigments of cyanobacteria and how they can be extracted and identified using different procedures and spectrophotometry. It emphasizes that the principal algal pigments are Phycobilins, Chlorophylls and Carotenoids.

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