99] Enzymatic preparation and properties of deoxyribonucleic acid and polydeoxyribonucleotides

Abstract

Publisher Summary This chapter describes the enzymatic preparation and properties of deoxyribonucleic acid (DNA) and polydeoxyribonucleotides. DNA will refer to the product synthesized in a complete reaction mixture. Polydeoxyribonucleotide refers to a product synthesized in a reaction mixture lacking one or more of the deoxyribonucleoside triphosphates of adenine, cytosine, guanine, and thymine and/or the primer DNA. For many purposes it is desirable to measure properties of DNA during initial phases of its synthesis under conditions in which the total DNA synthesized represents only a small fraction of the primer DNA present in the reaction mixture. Analysis has revealed that the newly synthesized material has a sedimentation constant in the neighborhood of 25 and a reduced viscosity of 40 dl/g. Heating the DNA in solution or hydrolyzing it with pancreatic DNase leads to an increase in the optical density at 260 m μ identical to similarly tested thymus DNA. The synthesis of a copolymer of deoxyadenylate and thymidylate, and a homopolymer of deoxyguanylate and deoxycytidylate is also explained in the chapter.