Synthesis and characterization of uracil base grafted polyacrylamides as polynucleotide analogs Dedicated to Professor Dr. Georg Manecke on the occasion of his 70th birthday, June 13, 1986.

Abstract

In conjunction with the previous studies of the adenine base grafted polyacrylamides, the uracil base grafted polyacrylamides and their monomer model compounds were prepared. In this case, however, an amine bond instead of an amide bond was used to attach the pendants onto the amino active site. A wider range of grafting efficiency (45–90%) and a smaller hypochromic effect were observed. This increase in grafting efficiency is responsible for the observed increase in percent hypochromicity. The reactivity ratios of the monomer model compounds with complementary bases, e.g., uracil and adenine, were estimated from a Finemann–Ross plot. Continuous mixing experiments involving the synthetic polyacrylamides with complementary bases suggested that polymer–polymer mixtures form base-paired complexes that stabilize the stacked conformation only in neutral aqueous solution. Electrostatic repulsion prÈvented such stability in acidic or alkaline aqueous solution. The collective information from NMR, UV, and CD spectra suggested that uracil based grafted poly(2-amino-2-methylpropyl)acrylamide (PDMPA) and poly(2-amino-2-methylbutyl)acrylamide (PDMBA) exist in limited ordered conformation.