Binding geometry of cobalt bleomycin, an empirical force-field analysis

Abstract

Empirical force-field calculations have shown that the co-ordination geometry 1 of bleomycin (BLM) binding to cobalt proposed by Umezawa and that, 2, proposed by Hilbers is sterically possible. In the calculations it was found that changing the charge on the metal ion has a significant effect on the BLM conformation, however the differences in conformation between the two binding geometries are much larger than those due to charge differences. Based on BLM–DNA docking studies, it is suggested that both the bithiazole tail and the metal-binding region of BLM with binding geometry 2 could be interacting with the minor groove of DNA.