Search

The affinity of L-DNAs, L-RNAs and L/D-DNAs for homopurine homopyrimidine d.s. D-DNA and s.s. D-RNA was probed by gel electrophoresis and CD spectroscopy. It was found that the L-modified oligomers do not bind to d.s. DNA and to natural RNA that contains all four natural bases. Thus they cannot be used, in general, for the control of gene expression according to the antigene and antisense methodologies. Heterochiral complexes with 1:1 stoichiometry and low thermal stability are formed, instead, by homopurinic L-RNA or L/D-DNA and homopyrimidinic L-RNA with the W/C complementary natural RNA sequences.

Using polyethylenglycol (PEG) as soluble supporting polymer, oligonucleotides have been prepared in high yield by an easy and fast procedure. The method looks promising for rapid synthesis of grams of short oligomers at reasonable cost.

The sodium salt of the dinucleoside phosphate d(GpG), dissolved in water, forms two mesophases which have been characterized, by optical microscopy, as being of the cholesteric (columnar chiral nematic, N∗) and hexagonal (M) type.