Depurination

Depurination is DNA alteration in which the hydrolysis of a purine base (Adenine or Guanine) from the deoxyribose-phosphate backbone occurs. After a depurination, the sugar phosphate backbone remains and the sugar ring has a hydroxyl (-OH) group in the place of the Adenine or Guanine. Around 1,000 Purines are lost this way each day in a typical mammalian cell. One of the main causes of depurination is the presence of endogenous metabolites in cell undergoing chemical reactions. This breaks the bond linking the purine with the pentose sugar.