Oligomers possessing the Morpholino phosphorodiamidate backbone were evaluated for resistance to a variety of enzymes and biologic fluids. A 25-mer was incubated with nucleases, proteases, esterases, and serum, and the reaction mixtures were directly analyzed by MALDI-TOF mass spectrometry. The 25-mer was completely resistant to 13 different hydrolases and serum and plasma. The excellent resistance of Morpholino phosphorodiamidates to enzymatic attack indicates their suitability for in vivo use.
Cell-free translation studies were carried out to compare the efficacy and specificity of four antisense structural types: DNA, phosphorothioate DNA (S-DNA), 2'-O-methyl RNA, and Morpholino oligos, a novel antisense structural type. In these studies, translational inhibition was assessed for two 20-mers of each structural type, where one 20-mer was complementary to its target sequence in rabbit alpha-globin mRNA and the other 20-mer contained three mispairs to that same target sequence. It is shown that at low concentration of antisense oligomer (50 nM) all four types provide high specificity, but the Morpholino oligos and 2'-O-methyl RNA afford better efficacy. At high oligomer concentration (3.5 microM), all four types provide high efficacy, but the Morpholino oligos and 2'-O-methyl RNA provide substantially better specificity than the DNA and S-DNA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.