2,2'-Bipyridine and hydrazide containing peptides for cyclization and complex quaternary structural control

A synthetic peptide containing two N -methyl lysines (Ac-K(N -Me)GYTGYTGK(N -Me)D-OH) was alkylated with bipyridine (bipy) ligands substituted at the fifth ( ) and sixth ( ) positions, thereby creating Ac-K(N -Me, N -Bipy)GYTGYTGK(N -Me, N -Bipy)D-OH. Peptides with 6-position bipyridine did not bind to Fe and Zn . Peptides with 5-position bipyridine bound these metals, and in the presence of one equivalent of a free bipy derivative folded into a macrocycle. Further, the free bipy derivative could also contain a cyclized peptide derived from hydrazone formation, resulting in complex but controlled quaternary peptide structure.