Stopped-flow experiments concentrations jumps

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). 

Combined experiments require a higher level of sophistication of the sample environment. Many examples can be foimd in the literature, for instance, fast stop-flow cells (99), concentration gradient devices (100), and temperature jump cells (101). In the following sections some techniqne combinations and the implications for sample cell construction are discnssed see also Reference 5. Before treating... 

Figure 6.4 Data from temperature jump relaxation experiments (Halford, 1973) on the interaction of the l-4 linked riimer of M-acetyl-D lucosamine with lysozyme at pH 4.4 monitoring H release. The concentration scale corresponds to the sum of the equilibrium concentrations of enzyme and ligand, (a) shows that the concentration dependence of the reciprocal relaxation time reaches a limit of 240 s which is similar to the fluorescence data of Holler et al., 1969. (6) illustrates a mechanism proposed by Halford (1975) from his relaxation and stopped-flow investigation of fluorescence changes and proton release over a range of pH.

The flow system can be operated either in the stopped or continuous mode. In the first case, as in other jump experiments, T is obtained from the transient change of the concentration of the species that is being observed. ... 

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