Acyclic model peptides with ionophoretic activity

Two linear synthetic peptides, N-tBoc-Pro-Gly-Ala-NHCH3 and N-tBoc-Pro-D-Ala-Ala-NHCH3, have previously been shown by us to complex with Ca2+ and form 2:1 (peptide:calcium) complexes. Here we report their binding to Pr3+ and demonstrate, by 1H NMR, the peptide-mediated transport of Pr3+ across dimyristoylphosphatidylcholine unilamellar vesicles via a 2:1 ion-sandwich complex.