Complex Formation between 9-Aminoacridine Derivatives and DNA

Abstract

In order to evaluate the influence of side-chains on the ability and on the specifity of binding to DNA of 9-Aminoacridines, some physic-chemical features of complexes derived from the interaction of DNA of different sources with 9-Aminoacridine and with N-9 alkyl (A), N-9-ω-hydroxyalkyl (B) and N-9– ω-diethylaminoalkyl – 9 amino-acridines (C) have been examined.

(C) derivatives bind strongly to DNA at sites which appear to be saturated when one dye molecule is bound for every four or five nucleotides; (A) and (B) derivatives bind in a weaker way to DNA at sites which appear to saturated when dye molecule is bound for every nine or ten nucleotides. After the primary sites have been filled, a secondary binding process can occur in a stronger way for (A) and (B) derivatives than for (C) derivatives.

The primary binding to DNA is not influenced by the base composition of the DNA itself. The different interaction of 9-Aminoacridine derivatives with DNA is consistent with biological behaviour previously observed.