Synthesis and structure of alpha/delta-hybrid peptides--access to novel helix patterns in foldamers.
Stimulated by an overview on all periodic folding patterns of alpha/delta-hybrid peptides with 1:1 alternating backbone provided by ab initio molecular orbital theory, the first representatives of this foldamer class were synthesized connecting novel C-linked carbo-delta-amino acid constituents and L-Ala. In agreement with theoretical predictions, extensive NMR spectroscopic analyses confirm the formation of new motifs of 13/11-mixed helical patterns in these peptides supported by the rigidity of the D-xylose side chain in the selected delta-amino acid constituents. Relationships between possible helix types in alpha/delta-hybrid peptides and their counterparts in other 1:1 hybrid peptide classes and native alpha-peptides are discussed; these indicate the high potential of these foldamers to mimic native peptide secondary structures. The design of alpha/delta-hybrid peptides provides an opportunity to expand the domain of foldamers and allows the introduction of desired functionalities through the alpha-amino acid constituents.
Discovery Laboratory, Organic Chemistry Division III, Indian Institute of Chemical Technology, Hyderabad 500 007, India. esmvee@iict.res.in
Gangavaram V M
GV
Sharma
Bommagani Shoban
BS
Babu
Kallaganti V S
KV
Ramakrishna
Pendem
P
Nagendar
Ajit C
AC
Kunwar
Peter
P
Schramm
Carsten
C
Baldauf
Hans-Jörg
HJ
Hofmann
D000596:Amino Acids / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013237:Stereoisomerism
D000596:Amino Acids; D010455:Peptides