The complex formation in aqueous solution between the polyelectrolytes poly(lysine) and pectate was studied focusing on the conformational changes of the polysaccharidic moiety. The findings suggest that the pectate adopts a superhelical conformation around the a helix of the poly(L-lysine). A threshold value of the degree of polymerization of the pectate chain enabling the transition of the peptide was determined by chromatographic and circular dichroism methods. Conformational analysis results are in agreement with the experimental findings and support the superhelical topology of the polyelectrolyte poly(L-lysine)-pectate complex.