Long-Range Electron Transfer in Heme Proteins

• Published in: Science (American Association for the Advancement of Science) Vol. 233; no. 4767; pp. 948 - 952
• Main Authors: Mayo, Stephen L., Ellis, Walther R., Crutchley, Robert J., Gray, Harry B.
• Format: Journal Article
• Language: English
• Published: Washington, DC The American Association for the Advancement of Science 29.08.1986; American Association for the Advancement of Science
• Subjects: Animals; Atoms & subatomic particles; Biological and medical sciences; Cytochrome c; Cytochrome c Group - metabolism; Cytochromes; Electrochemistry; Electron transfer; Electron Transport; Electrons; Fundamental and applied biological sciences. Psychology; heme; Hemeproteins; Hemeproteins - metabolism; Hemoproteins; horses; Horses - metabolism; Kinetics; Ligands; Metalloporphyrins - metabolism; Molecular biophysics; Myoglobin; Myoglobin - metabolism; Physical chemistry in biology; Physics; Porphyrins; Protein research; Proteins; Pseudomonas aeruginosa - metabolism; Thermodynamics; Tuna; Yeasts; Cytochrome c; Myoglobin; Hemoprotein; Electron transfer; Models; Metalloporphyrin; Kinetics; Zinc Complexes; Distance
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.3016897

Kinetic experiments have conclusively shown that electron transfer can take place over large distances (greater than 10 angstroms) through protein interiors. Current research focuses on the elucidation of the factors that determine the rates of long-range electron-transfer reactions in modified proteins and protein complexes. Factors receiving experimental and theoretical attention include the donor-acceptor distance, changes in geometry of the donor and acceptor upon electron transfer, and the thermodynamic driving force. Recent experimental work on heme proteins indicates that the electron-transfer rate falls off exponentially with donor-acceptor distance at long range. The rate is greatly enhanced in proteins in which the structural changes accompanying electron transfer are very small.