Title:
The purine world: experimental investigations into the prebiotic synthesis of purine nucleobases and intercalation of homopurine DNA duplexes

Thumbnail Image
Author(s)
Buckley, Ragan
Authors
Advisor(s)
Hud, Nicholas V.
Advisor(s)
Editor(s)
Associated Organization(s)
Organizational Unit
Supplementary to
Abstract
Formamide is a solvent of great interest to prebiotic chemists because it is liquid over a wide range, it is less volatile than either water or HCN, and it possesses a versatile reactivity. When formamide is heated in the presence of minerals or inorganic catalysts, a variety of products including purine nucleobases are generated. Irradiation of formamide reaction solutions with ultraviolet light increases the yield and diversity of products, and eliminates the need for a mineral catalyst. We have also performed formamide reactions in the presence of pyrite, a mineral which is likely to have been available on the primordial Earth, under a variety of atmospheric conditions. Our results indicate the greatest yield and diversity of products result from the combination of a pyrite mineral catalyst, heat, UV irradiation, and a carbon dioxide atmosphere. Purine nucleobases are simple to synthesize in model reactions and they stack well in aqueous solution; it has been hypothesized that the first nucleic acids were composed of only purine bases, and that water-soluble, cationic, aromatic molecules with large stacking surfaces (“”molecular midwives””) may have aided the assembly of the earliest nucleic acid analogs. We have characterized the interactions of various intercalators with a standard DNA duplex as well as with an antiparallel homopurine DNA duplex and have determined that molecules which possess four or more rings and a curved shape interact selectively with all-purine DNA; such molecules can serve as models for putative prebiotic midwives.
Sponsor
Date Issued
2012-06-13
Extent
Resource Type
Text
Resource Subtype
Dissertation
Rights Statement
Rights URI