Low-molecular-weight deoxyribonucleic acid polymerase from rabbit bone marrow

Biochemistry ◽  
1972 ◽  
Vol 11 (7) ◽  
pp. 1264-1272 ◽  
Author(s):  
Lucy M. S. Chang ◽  
F. J. Bollum
Keyword(s):  
Molecular Weight ◽  
Bone Marrow ◽  
Deoxyribonucleic Acid ◽  
Low Molecular Weight ◽  
Rabbit Bone

P2Z purinoceptor-associated pores induced by extracellular ATP in macrophages and J774 cells

1997 ◽  
Vol 273 (6) ◽  
pp. C1793-C1800 ◽  
Author(s):  
Robson Coutinho-Silva ◽  
Pedro Muanis Persechini
Keyword(s):  
Molecular Weight ◽  
Bone Marrow ◽  
Patch Clamp ◽  
Plasma Membranes ◽  
Extracellular Atp ◽  
Low Molecular Weight ◽  
Whole Cell ◽  
Voltage Dependent ◽  
J774 Cells ◽  
Bone Marrow Derived Cells

Millimolar concentrations of extracellular ATP (ATPo) can induce the permeabilization of plasma membranes of macrophages and other bone marrow-derived cells to low-molecular-weight solutes, a phenomenon that is the hallmark of P2Z purinoceptors. However, patch-clamp and whole cell electrophysiological experiments have so far failed to demonstrate the existence of any ATPo-induced P2Z-associated pores underlying this permeabilization phenomenon. Here, we describe ATPo-induced pores of 409 ± 33 pS recorded using cell-attached patch-clamp experiments performed in macrophages and J774 cells. These pores are voltage dependent and display several properties of the P2Z-associated permeabilization phenomenon: they are permeable to both large cations and anions, such as tris(hydroxymethyl)aminomethane, N-methyl-d-glucamine, and glutamate; their opening is favored at temperatures higher than 30°C; they are blocked by oxidized ATP and Mg2+; and they can be triggered by 3′- O-(4-benzoylbenzoyl)-ATP but not by UTP or ADP. We conclude that the pores described in this report are associated with the P2Z permeabilization phenomenon.

scholarly journals Deoxyribonucleic acid polymerases of Euglena gracilis. Purification and properties of two distinct deoxyribonucleic acid polymerases of high molecular weight

1975 ◽  
Vol 151 (2) ◽  
pp. 227-238 ◽  
Author(s):  
A G McLennan ◽  
H M Keir
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Euglena Gracilis ◽  
Deoxyribonucleic Acid ◽  
Deae Cellulose ◽  
Low Molecular Weight ◽  
Optimum Conditions ◽  
Electrophoretic Mobilities ◽  
Substrate Activation ◽  
Purification And Properties

Two DNA polymerases of high molecular weight, pol A (mol.wt. 190 000) and pol B (mol.wt. 240 ooo), have been purified 6300-fold and 1600-fold respectively from an extramitochondrial supernatant of a bleached strain of Euglena gracilis. They have very similar requirements when assayed with an ‘activated’-DNA primer-template [the optimum conditions of pH and ionic (K+ and Mn2+) composition being 7.2, 25 mM and 0.2 mM respectively]. 0.2 mM-Mn2+ was about 1.5-2-fold as effective as 2 mM-Mg2+, owing to substrate activation by deoxyribonucleoside 5′-triphosphates in the presence of Mn2+. Km values for the triphosphates in the absence of activation were about 10(-6)M with Mn2+ and 8 × 10(-6) M with Mg2+ for both enzymes. They were inhibited to the same extent by N-ethylmaleimide, novobiocin and o-phenanthroline, but differed in their chromatographic behaviour on DEAE-cellulose and in their electrophoretic mobilities on polyacrylamide gel. No evidence was found for the existence in these cells of a DNA polymerase of low molecular weight, but there were indications that a third enzyme of high molecular weight might exist.

scholarly journals Deoxyribonucleic acid synthesis in mammalian systems. Permealysed Ehrlich ascites cells in vitro first label Okazaki-type low-molecular-weight deoxyribonucleic acid and then high-molecular-weight deoxyribonucleic acid

1972 ◽  
Vol 130 (4) ◽  
pp. 959-964 ◽  
Author(s):  
Leigh A. Burgoyne
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Preparation Procedure ◽  
Low Molecular Weight ◽  
Deoxyribonucleic Acid Synthesis ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells

During the evaluation of a method of preparing permealysed Ehrlich ascites cells, shortterm labelling experiments were carried out with d[3H]TTP. In the first minute the bulk of the label appeared as low-molecular-weight pieces of DNA. Subsequently the label appeared in DNA of much higher molecular weight. A brief description of the preparation procedure and the properties of the product is provided. Evidence is presented to show that the nucleotide was incorporated directly without intermediate conversion into dTMP or thymidine.

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