title: Bicyclic peptides. VI. Synthesis, conformation, and ion-binding of two bicyclic nonapeptides.
abstract: Two related homodetic bicyclic nonapeptides (cyclo Glu-X-Pro-Gly-Lys-X-Pro-Gly)-cyclo (l gamma----5 epsilon), X = Ala(BCP2), X = Leu(BCP3) have been synthesized using conventional solution phase methods involving mixed anhydride coupling reactions starting with appropriately protected naturally occurring amino acids. The conformation and ion binding properties of BCP2 have been studied by nuclear magnetic resonance and circular dichroism techniques. The results of these studies have been compared to those of BCP3. The presence of Ala caused both Ala-Pro bonds to be trans in free BCP2. This characteristic imparted subtle differences to the ion-binding properties of BCP2 as compared to free BCP3 which has one cis Leu-Pro bond and one trans Leu-Pro bond.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA.
authors.forename: G C
authors.initials: GC
authors.lastname: Zanotti
authors.forename: B E
authors.initials: BE
authors.lastname: Campbell
authors.forename: K R
authors.initials: KR
authors.lastname: Easwaran
authors.forename: E R
authors.initials: ER
authors.lastname: Blout
mesh_terms: D002413:Cations, Divalent; D002942:Circular Dichroism; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010456:Peptides, Cyclic / Q000138:chemical synthesis*; D011485:Protein Binding; D011487:Protein Conformation; D013329:Structure-Activity Relationship
chemical_list: D002413:Cations, Divalent; D007202:Indicators and Reagents; D010456:Peptides, Cyclic