Persistence length determination

Qbd persistence length determined by Benoit-Doty method... 

Figure 19.17 Persistence-length determination of the macroscopic structures of the tail segments of mutants with (a) longer and (b) shorter ID regions. The mean square point-to-point distance is plotted as a function of the macroscopic contour length between the corresponding two points. The solid lines indicate the best-fit curves of Eq. 19.3 with (a) p = 10.5 nm and (b) p = 12.1 nm. The inset image in (a) indicates the relationship between the microscopic contour and the macroscopic structure. The microscopic contour is schematically drawn as a thin white line.

From disaccharide analysis, few authors predict the conformation of the poly a-D galacturonan as well as the role of the charge density [35,36] they determine the persistence length Ip that will allow us to explain the behaviour in solution. 

With the aim to establish an [rj]-M relation (Equation (36)) for universal calibration and for the determination of the persistence length, intrinsic viscosities were measured with an Ubbelohde capillary viscometer. The respective data are also included in Table 3. 

For worm-shaped entities we will not determine the extension, but only the persistence length of the entities (cf. p. 165). 

Geometrical and flexibility data pertaining to the same polymers are also given in Table 1, namely the persistence length and the average chain-to-chain interaxial distance D. The first five polymers in Table 1 have D values smaller than 6 A, unlike all the following polymers (i.e., no. 6 to 19 in Table 1, Class II). This is a consequence of the relatively bulky substituents carried by Class II polymer chains. For some of the polymers in Table 1 the C0o and P literature values are widely scattered or unavailable. In those cases lower-limit values of P from experimentally determined geometrical parameters, are predicted from our model by suitable interpolation and reported within parentheses. 

The persistence length of poly(dG-dC) was determined to be 800 A,(148) about 1.6 times the value characteristic of native DNAs. Possible long-term changes in these light scattering samples were not investigated. 

Mills JB, Vacano E, Hagerman PJ (1999) Flexibility of single-stranded DNA use of gapped duplex helices to determine the persistence lengths of poly(dT) and poly(dA). J Mol Biol 285 245-257... 

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