Modular Synthesis of de novo-Designed Metalloproteins for Light-Induced Electron Transfer

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 95; no. 20; pp. 11526 - 11531
• Main Authors: Rau, Harald K., DeJonge, Niels, Haehnel, Wolfgang
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 29-09-1998; National Acad Sciences; National Academy of Sciences
• Subjects: Amino Acid Sequence; Amino acids; Argon; Biochemistry; Biological Sciences; Circular Dichroism; Cyclic peptides; Cytochromes; Drug Design; Drug Stability; Electron Transport - radiation effects; Heme - chemistry; Kinetics; Ligation; Light; Metalloproteins - chemical synthesis; Metalloproteins - metabolism; Metalloproteins - radiation effects; Models, Molecular; Molecular Sequence Data; Molecular Weight; Oxidation-Reduction; Peptides; Physical Sciences; Protein Conformation; Protein Structure, Secondary; Proteins; Ruthenium; Ruthenium - chemistry; Wavelengths
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.95.20.11526

The design and chemical synthesis of two de novo four-helix bundle proteins is described; each protein has two bound cofactors. Their construction from purified peptides is based on the modular assembly of different amphiphilic helices by chemoselective coupling to a cyclic peptide template. In the hydrophobic interior of the antiparallel four-helix bundle these proteins contain a heme in a binding pocket with two ligating histidine residues. A rutheniumtris(bipyridine) complex is covalently bound to different positions at the hydrophilic side of one of the heme-binding helices. Laser-induced electron transfer across the varied distance through this helix has been studied and compared with a pathway analysis. The UV-visible, CD, and mass spectra are consistent with the structure and orientation predetermined by the template.