Molecule of the month, PDE4DIP

Abstract

We can't live without oxygen. Our cells rely on oxygen as the final acceptor of electrons in respiration, allowing us to extract far more energy from food than would be possible without oxygen. But oxygen is also a dangerous compound. Reactive forms of oxygen, such as superoxide (oxygen with an extra electron), leak from the respiratory enzymes and wreak havoc on the cell. This superoxide can then cause mutations in DNA or attack enzymes that make amino acids and other essential molecules. This is a significant problem: one study showed that for every 10,000 electrons trans- ferred down the respiratory pathway in Escherichia coli cells, about 3 electrons end up on superoxide instead of the proper place. To combat this potential danger, most cells make superox- ide dismutase (SOD, shown here from PDB entry 2sod), an enzyme that detoxifies superoxide. 2sod