Complex Formation of Poly-L-lysine with Sodium Cellulose Sulfate

The interactions between poly-L-lysine (PLL) and sodium cellulose sulfate (SCS) have been studied as functions of both the pH and the PLL-to-SCS ratio by using circular dichroism spectroscopy. SCS reacted with PLL and induced the formation of the α-helix of PLL. The induced helical content was proportional to the SCS mole fraction in the complex, but deviated from the stoichiometrical relationship. In this system, no disturbing effects on the formation of α-helix of PLL were observed. These results were different from those for the mucopolysaccharides—PLL systems reported by Gelman, et al., in some respects, and could be interpreted by taking into account the chain conformations and the location of sulfonic groups along the SCS backbone chains.