Nucleation of beta-hairpin structures with cis amide bonds in E-vinylogous proline-containing peptides.
Synthesis and conformational studies of peptides containing the E-vinylogous prolines 1 (VPro1) and 2 (VPro2), Boc-Ala-Val-VPro1-Xaa-Leu-OMe (3, Xaa = Gly; 4, Xaa = Phe), Boc-Ala-Val-VPro2-Xaa-Leu-OMe (5, Xaa = Gly; 6, Xaa = Phe), Boc-Leu-Ile-Val-VPro1-Xaa-Leu-OMe (7, Xaa = Gly; 8, Xaa = Phe), and Boc-Leu-Ile-Val-VPro2-Xaa-Leu-OMe (9, Xaa = Gly; 10, Xaa = Phe), were carried out. It has been shown that both VPro1 and VPro2 lead to the formation of 12-membered intramolecularly hydrogen bonded structures very similar to type VI beta-turns with a cis Xaa-VPro amide bond in the major conformers in all the peptides 3-10, resulting in the nucleation of beta-hairpin type structures in these molecules in CDCl(3).
Chakraborty
Tushar K
TK
Indian Institute of Chemical Technology, Hyderabad 500 007, India. chakraborty@iict.ap.nic.in
Ghosh
Animesh
A
Kumar
S Kiran
SK
Kunwar
Ajit C
AC
D006860:Hydrogen Bonding; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D009690:Nucleic Acid Conformation; D010455:Peptides / Q000138:chemical synthesis*; D011392:Proline / Q000737:chemistry*
D007202:Indicators and Reagents; D010455:Peptides; D011392:Proline