Physico-Chemical Changes in Irradiated Nucleic Acids

Abstract

The nucleic acids have a fundamental role in the maintenance of vital processes. While deoxyribonucleic acid (DNA) carries genetic information, the various ribonucleic acids fulfil important functions in the realization of this information (see Chapter 11.1). The key position in biological processes occupied by nucleic acids made the investigation of the action of radiation on DNA and RNA the central theme of molecular radiation biology. As in the case of enzymes, the main problem is to correlate loss of biological function with the occurrence of physical and chemical changes, and thereby to gain an understanding of the inactivation mechanism. There are numerous biological functions of the nucleic acids that are accessible to measurement, as well as physico-chemical changes induced by irradiation, so that the simultaneous discussion of both of these facets would affect the clarity of this presentation. The physico-chemical and chemical changes occurring in irradiated nucleic acids will, therefore, be considered first, and in the three succeeding chapters an attempt will be made to correlate these changes with the inhibition of certain biological functions. This will not always be simple, as in most cases only one of these effects has been examined by a particular author. The attempts to relate functional with physico-chemical changes have only developed during recent years, especially in the work with bacteriophages.KeywordsStrand BreakDouble Strand BreakSingle Strand BreakPyrimidine BaseNucleotide PairThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.