Cyclam glycoconjugates as lectin ligands and protective agents of metal-induced amyloid aggregation

Transition metal ion complexes of a number of chelators have been widely investigated due to their biological properties. The sugar conjugation of metal complexes has resulted in improved properties of the systems, such as solubility and lectin recognition. In this paper, we report the synthesis, the characterization of new glucose and galactose conjugates of 1,4,8,11-tetraazacyclotetradecane (cyclam) and their Cu^II complexes. The glycoconjugates were proved to be protective agents of metal-induced amyloid aggregation. The binding constants of the galactose conjugate KA1 =(3.07±0.16)×10⁷ and KA2 =(2.13±0.04)×10⁷ M^-1 with the lectin Ricinus communis agglutinin (RCA120) as a model of galactose-specific human lectin were obtained with surface plasmon resonance.