Asymmetric intercalation of N1-(acridin-9-ylcarbonyl)spermine at homopurine sites of duplex DNA

Abstract

N ¹ -(Acridin-9-ylcarbonyl)spermine binds at 5′-pu-p-pu..5′-py-p-py sites of DNA with the acridine moiety asymmetrically intercalated, stacked between the two purine bases; the spermine moiety interacts with the homopyrimidine phosphodiester backbone of the intercalation site and protects against DNase I cleavage of this backbone, but does not protect against cleavage of the homopurine backbone at the same intercalation site.