1. Treatment of Micrococcus lysodeikticus polynucleotide phosphorylase (nucleoside diphosphate-polynucleotide nucleotidyltransferase) with trypsin causes a preferential loss of its cytidine diphosphate and uridine diphosphate polymerization activities. 2. The phosphorolytic activity of the enzyme towards polycytidylic acid is unaffected in conditions in which the cytidine diphosphate-polymeriza...

We prcsent a study of the electrodynamic behavior of concentrated suspensions of spherical polyelectrolyte brushcs (SPBs). The dynamic mobility of the SPBs exhibits giant values. Concomitantly, . the dielectric spectra of suspensions of these particlcs display enormous loss peaks in the kHz frequency range. The strong dielectric relaxation is a direct consequence of the inhomogeneity of the cou...

tellurium nanostructures have been prepared by physical vapor deposition method in a tube furnace. the experiments were carried out under argon gas flow at a pressure of 1 mbar. tellurium powder was evaporated by heating at 350°c and 430°c and was condensed on substrates at 110–250°c, in the downstream of argon gas flow. the products were characterized by field emission scanning electron micros...

Hepatitis C virus NS3 helicase is an enzyme that unwinds double-stranded polynucleotides in an ATP-dependent reaction. It provides a promising target for small molecule therapeutic agents against hepatitis C. Design of such drugs requires a thorough understanding of the dynamical nature of the mechanochemical functioning of the helicase. Despite recent progress, the detailed mechanism of the co...

Ribonucleoside diphosphates react to form polyribonucleotides and inorganic phosphate. Studies of the nature of nucleotide incorporation into nucleic acid in Escherichia coli led to the recognition of a similar reaction by Littauer and Kornberg (3). Beers (4,5) and Olmsted (6,7) have investigated the phosphorylase in Micrococcus lysodeikticus. Heppel et al. (8-10) have elucidated the structure ...

It has been demonstrated (1, 2) that dietary guanine is not utilized to a significant extent by the rat for nucleic acid synthesis but that adenine may be utilized by the rat as a precursor of both polynucleotide adenine and polynucleotide guanine (2). Recent studies with labeled glycine (3) and nucleic acid (4) have indicated that polynucleotide guanine may also arise by mechanisms not involvi...

A cherished tenet of nucleic acid enzymology holds that synthesis of polynucleotide 3'-5' phosphodiesters proceeds via the attack of a 3'-OH on a high-energy 5' phosphoanhydride: either a nucleoside 5'-triphosphate in the case of RNA/DNA polymerases or an adenylylated intermediate A(5')pp(5')N--in the case of polynucleotide ligases. RtcB exemplifies a family of RNA ligases implicated in tRNA sp...

A brief review is given on recent studies of charged soft matter solutions, as modelled by the ‘primitive’ approach of strongly coupled Coulomb systems, where the solvent just enters as a dielectric background. These include charged colloids, biological macromolecules such as proteins and DNA, polyelectrolytes and polyelectrolyte stars. Also some original results are presented on colloid–polyel...

The driven translocation kinetics of a single strand polynucleotide chain through a nanopore is studied using off-lattice Monte Carlo simulations, by which the authors demonstrate a novel method in controlling the driven polymer transport through a nanopore by a rotating electric field. The recorded time series of blockade current from the driven polynucleotide transport are used to determine t...

The poly(dA) dependent T4 polynucleotide ligase catalyzed polymerization of oligodeoxythymidylates is dependent upon duplex stability. The antibiotics ethidium bromide, netropsin and Hoechst 33258 stabilize the duplex poly(dA) . P(dT)n (n = 6-10) to thermal denaturation. Ethidium bromide to DNA ratio of 1.25 and netropsin or Hoechst 33258 to DNA ratio of 0.1 the Tm of d(pT) 10 . poly (dA) was i...