Conformation and anion binding properties of cyclic hexapeptides containing L-4-hydroxyproline and 6-aminopicolinic acid subunits.

ABSTRACT: Two cyclic hexapeptides containing alternating all R and all S configured Ll-(4R/S)-hydroxyproline and 6-aminopicolinic acid subunits are presented, and the influence of the hydroxyl groups on the solubility, conformation, and receptor properties is investigated. Cyclopeptide 2, containing the natural 4R configured hydroxyproline, adopts a conformation similar to that of the unsubstituted peptide 1, which is able to bind anions such as halides and sulfate in aqueous solution. 2 also interacts with these anions, but whereas 1 forms sandwich type 2:1 complexes, in which the anion is bound by two cyclopeptide moieties, 2 forms 1:1 complexes. The stabilities of the halide and sulfate complexes of 2 range between 10(0) and 10(2) M(-1) in 80% D(2)O/CD(3)OD. Complex formation is detectable even i

SUBMITTER: Kubik S 

PROVIDER: S-EPMC122733 | biostudies-literature | 2002 Apr

REPOSITORIES: biostudies-literature