Crystal structures of valinomycin with potassium tetrachloroaurate and rubidium tetrachloroaurate with comparisons to other monovalent cation complexes

A total of 19 different crystal forms of complexes of valinomycin or its analogues with monovalent cations have been observed. The crystal structure determinations of valinomycin potassium tetrachloroaurate and valinomycin rubidium tetrachloroaurate are given here.Including this work complete structure determinations have now been published on 7 with 2 more soon to appear. Comparisons of these structural results suggest that the valinomycin complex opens at the D-valyl (lactyl) end and that contacts are possible between the complexed cation and other molecules. Such contacts may play an important part in membrane transport.