Designing metal-peptide models for protein structure and function

Recent progress in the rational design of metal sites within peptide model systems shows increasing control in the placement of metals within helical bundles and inclusion of sophisticated elements such as second-sphere ligan d interactions. A crystallographically characterized two-metal peptide mode l for diiron proteins represents a major achievement in de novo design meth odologies. Increasingly complex and robust models for electron transfer thr ough and between helices, and electrode-supported electron-transfer peptide s, have been constructed. Design elements for peptide-supported ferredoxins and mononuclear Fe(tl) and Zn(tl) sites have been refined.