On the protonophoric activity of oxazolomycin.

By the use of an artificial lipid membrane model we have shown that the antibiotic oxazolomycin (Streptomyces albus) is an effective protonophore at pH < 7.0 but conveys both protons and monovalent cations such as potassium at pH > 7.5 as a passive carrier. The ionophoric properties are suggested to be correlated with its antibacterial, antiviral, and cytotoxic activities.