Deamination describes the loss of an amine group from a molecule.
Deamination is likely to have played an important role in the availability of the biological building blocks of life. In the case of the nucleobases, the components of RNA and DNA, the dominant decomposition products of their exocyclic amine-bearing bases adenine, guanine, and cytosine are the deaminated products hypoxanthine, xanthine, and uracil, respectively. A calculation of the half-lives for the rates of decomposition of these bases shows that these compounds are not stable on a geologic timescale at temperatures much above 0 °C. This has led to the suggestion that life would be more likely to evolve under cold conditions, where biologically important material can accumulate, rather than at elevated temperatures such as hydrothermal vents, where they would be rapidly destroyed (Levy and Miller 1998).
Deamination is important for other biomolecules such as amino acids. In particular, the...