Pectate-poly lysine

Fig. 11.1. The CD spectra of the individual acidic polysaccharides and polypeptides (7) potassium pectate (2) alginate rich in L-guluronate (3) alginate rich in D-mannuronate 4) poly(L-lysine) (5) poly(D-lysine) ...

The CD spectra of d- and L-polylysines in the presence of potassium pectate are given in Figs. 11.2 and 11.3. The spectral shape of complexes with poly(L-lysine) clearly indicates the presence of induced a-helical structure. 

The CD spectra of poly(D-lysine) reflect a markedly low degree of complexation. The prevalent part of poly(D-lysine) remains in unchanged random coil arrangement. The extent of complexation may be judged from comparison with the CD spectrum of poly(D-lysine) at pH = 11.3 (Fig. 11.1). Complexation efficiency of poly(L-lysine) with pectate is almost 100% while with poly(D-lysine)... 

Fig. 113. The CD spectrum of poly(D-lysine), in the presence of potassium pectate potassium pectate with addition of 20% (/), 40% (2), 60% (5), 80% 4) and 100% (5) poly(D-Iysine)...

The interaction with poly(D-lysine) appears to be more effective (approximately 50%). The complexation efficiency with enantiomeric poly(L-lysine) is about 20% only. This difference, smaller than with pectate, reflects the fact that the D-mannuronate arrangement in alginate is rather flexible due to the j8(l-4)... 

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