Transition Metal Complexes of Linear and Cyclic Pseudopeptides
Many enzymes require metal ions for substrate binding and product formation. In order to study the complexation of transition metal ions and the possible catalytic activities of the formed complexes, we synthesized linear and cyclic pseudopeptides and peptides with different sequences and sizes. We are interested in testing and improving the modeling program COSMOS™. Therefore, all synthesized structures are in advance conformationally designed for complexation of certain metals. Some metallo enzymes contain two or more metal ions. Therefore an octapeptide with two different chelating centers was designed for complexation of Ni++ and Co++. We were interested in developing a synthetic strategy for the assembly of homo and hetero dinuclear metal complexes of this cyclic peptide. Complexation of metal ions and subsequent polarization of the complex bound water are assumed to be prerequisites for catalytic hydrolysis of carbonic or phosphoric acid esters.