Conformation and dynamics of dimeric ureido‐balhimycin

The conformation of the antibiotic ureido‐balhimycin has been investigated by proton nmr and refined with computer simulations. The dimeric structure cj ureido‐balhimycin was established by unambiguous identification of 6 nuclear Overhauser effects (NOEs) as intermonomeric, out of the total of 186 NOEs observed. Via distance geometry calculations the antiparallel orientation of the two monomers was demonstrated. Further refinement by molecular dynamics simulations provided the essential hydrogen bonds and aromatic interactions responsible for interfacial stabilization. The computational protocol illustrated here (distance geometry to define the coarse topology and molecular dynamics for refinement) should find general applicability in the study of homodimers. © 1995 John Wiley & Sons, Inc.