T2 bacteriophage

Temperature jump studies on the binding dynamics of 5 with ct-DNA and T2 Bacteriophage DNA showed two lifetimes in the relaxation kinetics.117 The observed... 

The non-linear dependence of the relaxation process on the DNA concentration was also observed in stopped-flow experiments and the same mechanism, i.e. fast pre-equilibrium followed by a slow intercalation step, was proposed." This latter study did not report values for the individual rate constants. The mechanism proposed in Scheme 4 was employed in subsequent studies despite the criticism on the accuracy for the data related to the fast kinetic component (see below). The original temperature jump study also showed that the relaxation kinetics depend on the structure of the DNA.117 The slower intercalation rate for 5 with T2 Bacteriophage DNA when compared to ct-DNA was ascribed to the glucosylation of the former DNA (Table 3). 

It was concluded39 from these studies that the two nucleotides obtained by enzymic hydrolysis of the deoxyribonucleic acid of T2 bacteriophage are 2-deoxy-5 -(hydroxymethyl)cytidylic acid and a glucose derivative thereof. It was also concluded that the glucose residue is affixed to the pyrimidine portion of the nucleotide and nucleoside of 5-(hydroxymethyl)-cytosine and, on the basis of the near identity of the spectra of the two nucleotides of 5-(hydroxymethyl)cytosine, it was suggested that the hexose is attached to the hydroxymethyl group of the pyrimidine. 

Another sample class that is well separable by S-FFF are viruses [182,433]. Molar masses were determined [80,433,447] including T2 bacteriophage [80,171,174], R17 E. coli bacteriophage [31] and the T4D virus, for which it was shown that the infectivity of the virus remained essentially unaffected by its passage through the FFF channel and detector system. 

In 1952, Alfred Hershey and Martha Chase showed T2 bacteriophage inject only DNA into cells and this is sufficient to make more T2 bacteriophage (Figure 4.8b). 

The overall shape of a virus varies. The classic viral shape most often seen in the literature has a hexagonal capsid with a rod sticking out of it that attaches to the host cell and acts like a syringe to inject the nucleic acid. Figure 14.2 shows the T2 bacteriophage of E. colt, a classic example of a virus of this shape. Tobacco mosaic virus (TMV), on the other hand, has a rod shape, as shown in Figure 14.3. 

Although nearly all the proteins synthesized by a bacterial cell after it has been infected with T2 bacteriophage are determined by the viral genome, some bacterial proteins are also required for successful infection. What bacterial enzyme is needed to initiate viral infection when T2 DNA first enters the cell ... 

Figure 19. T2 bacteriophages attach to the surface of a bacterial cell before penetration of the cytoplasm the infected cell will be lysed. Phage http //en.wikipedia. org/wiki/File Phage.jpg by Dr Graham Beards http //en.wikipedia.org/wiki/User Graham Beards is licensed under CC BY-SA 3.0 http //creativecommons.org/ licenses/by-sa/3.0/.

Fig. 14. Differential pulse voltammograms of T2 bacteriophage DNA at the pyrolytic graphite electrode in 0.2 M sodium acetate, pH 6.4. (A) native DNA (B) thermally denatured DNA. DNA was at the concentration of 0.3 mg/ml.

An example of a similar type of cooperative transformation is shown in Fig. 3.17 for different molecular weight nucleic acids (obtained by shear degradation) from T2 bacteriophage.(62) This temperature induced transformation is quite clear in the figure. At low temperature all the appropriate bases are bonded, one to another at high temperature, in the disordered state, the bases are no longer bonded. The... 

However, viscosity data obtained after treatment with DNAase is probably reliable. Cohen (53) gives the specific viscosity of DNAase-treated T2 bacteriophage as 0.0167 at 0.02 mg. P per cc. Herriott and Barlow (130) report the viscosity of the same virus as 0.12 0.05 per mg. N. 

Anderson in 1943 (8) noted that the internal structure of T2 bacteriophage escapes from the membrane when the virus is treated with acid,... 

Trimble, R. B., Maley, G. F., Maley, F. The in vitro s5mthesis of T2 bacteriophage-induced deoxycytidylate deaminase and its regulation by allosteric effectors. Arch. Biochem. Biophys. 153, 515-525 (1972b). 

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