Preparation and properties of the repeating sequence polymers d(A-I-C)n-d(I-C-T)n and d(A-G-C)n-d(G-C-T)n

The repeating sequence polymer d(A-I-C)n-d(I-C-T)n has been prepared using the chemically synthesized oligomers d(A-G-C)4 and d(C-T-G)4 and the DNA polymerase from Micrococcus luteus. The enzymatically synthesized polymer was used as template for preparation of d(A-G-C)n-d(G-C-T)n. Both deoxyribonucleotide polymers were characterized by nearest neighbor analyses, buoyant density measurements in cesium chloride and cesium sulfate, melting temperature, and circular dichroism (CD) spectra. The ribopolymers r(A-I-C)n-r(I-C-U)n and r(A-G-C)n-r(G-C-U)n were transcribed from d(A-I-C)n-d(I-C-T)n, and their CD spectra were compared with those of the respective deoxyribonucleotide polymers.