... in the guan-ine ring, at distances of 1.6 A ˚(Fig. 2B). The carbonyl, a hydrogen-bond acceptor group of guanine,is replaced by a donor amino group in adenine,whereas the guanine amino at ... parameters of binding [39] as the subject of a separate investigation. In this regard, weak interactions in the adenine ringbinding site have been identified in B. stearother-mophilus [19] and T. brucei ... Bioquı´mica, Instituto Nacional de Cardiologı´ a, Me´xico D.F., Me´xico2 Departamento de Ciencias Naturales Unidad Cuajimalpa and Departamento de Quı´mica Unidad Iztapalapa, Universidad Auto´nomaMetropolitana,...