Nucleic Acids in Chemistry and Biology

11.1 Spectroscopic Techniques 11.1.1 Ultraviolet Absorption The light absorption characteristics of nucleic acids^1 result from ...

steeper with increasing length of the oligonucleotide. Simple sigmoid melting curves are observed for many DNA samples, but it i ...

The donor–acceptor distance (R) is related to ETby the system constant Ro, which is the distance at which there would be 50% of ...

11.1.3 Circular and Linear Dichroism Circular dichroism(CD) is a widely used form of chiral spectroscopy which has been applied ...

Modern CD spectrapolarimeters are often equipped with Peltier temperature control, automated titration and stopped-flow accessor ...

calibration with X-ray crystallography of nucleic acid samples. Such ‘marker bands’ are sensitive to helical type and can be use ...

of the particular spin. The position or frequency of the spectral line is called the chemical shift, the fine structure observed ...

Other 2D experiments permit accurate coupling constants to be measured and from these the conformation may be determined, for ex ...

conformation about an N-glycosylic bond is synor anti(Figure 11.9). This information lends support to the quantitative analysis ...

Once all or most of the^1 H chemical shifts have been assigned, it simply remains to quantify NOESY cross-peaks. These, together ...

structures from NMR data has been an important issue until recently.12,13Approaches are now available to enable the measurement ...

search for possible solutions to the phase problem. By use of all the intensities and phase values from the dif- fraction patter ...

Classical experiments of Meselson and Stahl in 1957 utilised equilibrium density gradient centrifuga- tion in caesium chloride ( ...

of a macromolecule. A uniform solution of the sample is placed into the centrifuge cell, which is spun at high speed. This cause ...

molecular mass and the concentration of macromolecule. For globular structures such as proteins with molecular weight
500kDa or ...

An alternative explanation assumes reptation, which is an end-to-end movement of the DNA through the pores of the gel. This theo ...

the enthalpy change associated with either a binding interaction or a heat-induced conformational transition for nucleic acids a ...

A single DSC experiment can provide a large amount of thermodynamic information, much of which cannot be obtained by any other t ...

the area under such a curve represents the entropy change for the transition. From this information the value of Gcan be evalua ...

dehydration and coating processes. Several images can then be recorded on the same sample, which is tilted between recordings, a ...