INCREASED DNA-BINDING AND SEQUENCE DISCRIMINATION OF PNA OLIGOMERS CONTAINING 2,6-DIAMINOPURINE

The synthesis of a diaminopurine PNA monomer, N[N-6-(benzyloxycarbonyl )-2,6-diaminopurine-9-yl] acetyl-N-(2-t-butyloxycarbonylaminoethyl)gly cine, and the incorporation of this monomer into PNA oligomers am desc ribed, Substitution of adenine by diaminopurine in PNA oligomers incre ased the T-m of duplexes formed with complementary DNA, RNA or PNA by 2.5-6.5 degrees C per diaminopurine, Furthermore, discrimination again st mismatches facing the diaminopurine in the hybridizing oligomer is improved, Finally, a homopurine decamer PNA containing six diaminopuri nes is shown to form a (gel shift) stable strand displacement complex with a target in a 246 bp double-stranded DNA fragment.