ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Clipped autocorrelation functions for the fluctuating intensity of light scattered from dilute solutions of poly-L-lysine in 0.2 M NaBr have been observed over a wide range of time scales down to 1.83 μsec, and over a wide range of pH. Two poly-L-lysine samples of molecular weight 35,000 and 200,000, respectively, were compared to determine the extent of draining of the so-called random-coil configuration. The observed correlation functions were in general very satisfactorily represented by simple translation diffusion of single molecules. At high pH ∼10-10.4, there was evidence of considerable aggregation, but no indication whatsoever of any unusually fast component, as reported recently by Jamieson et al. for poly-L-lysine HBr in the absence of salt.A 30% rise in the diffusion coefficient to a peak at pH 10 parallels the previously reported dip in the intrinsic viscosity, and is interpreted in terms of a more compact structure in that pH region between the coil and helix extremes.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1974.360130506
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