INTERACTIONS OF NUCLEIC-ACIDS WITH DISTAMYCINS - BINDING OF DST-3 TO D(CGTTTAAACG)2 AND D(CGTACGTACG)2

The binding between Distamycin 3 and the palindromic duplexes d(CGTTTAAACG)2 and d(CGTACGTACG)2 was investigated by two indipendent techniques: UVVis absorption in the Job's plot approach and Induced Circular Dichroism. Both decamers bind two molecules of peptide per duplex, with close overall affinities. This result indicates that a row of six A:T base pairs can accommodate two molecules of drug and that the minimal binding site of Distamycin 3 can consist of just two A:T base pairs.