Synthesis and Evaluation of RNA Transesterification Efficiency Using Stereospecific Serinol-Terpyridine Conjugates

Abstract

Six novel artificial ribonucleases were synthesized employing a stereochemically pure abasic serinol backbone residue for attachment of the RNA transesterification agent copper(II) terpyridine. These stereochemically pure abasic residues were synthesized as phosphoramidite building blocks from the parent l -serine and d -serine starting building blocks and incorporated into oligonucleotides via solid-phase DNA synthesis. These artificial ribonucleases were constructed to determine if the stereochemistry of the alpha carbon of an abasic serinol residue has influence over RNA transesterification through selective placement of a pendant transesterification agent in either the major or minor groove. The novel artificial ribonucleases and previously synthesized artificial ribonucleases were challenged with a 28-mer and 159-mer RNA substrate. It was determined that the stereochemistry of the carbon atom derived from the α-carbon of serine did not influence the extent of cleavage in these studies using copper(II) terpyridine conjugated artificial ribonucleases.

Keywords:

• Antisense
• Artificial Ribonuclease
• RNA Cleavage
• Transesterification
• Abasic Backbone
• Serinol

Acknowledgment for partial support of this research is made by to the donors of the Petroleum Research Fund, administered by the ACS and the National Science Foundation (CHE-9802660). Mass spectrometry was provided by the Washington University Mass Spectrometry Resource, an NIH Research Resource (Grant No. P41RR0954). We thank Dr. Lee Ratner of the Washington University Medical School (St. Louis, Missouri) for the plasmid containing the HIV gag-gene fragment.