12/10- and 11/13-mixed helices in alpha/gamma- and beta/gamma-hybrid peptides containing C-linked carbo-gamma-amino acids with alternating alpha- and beta-amino acids.
New classes of alpha/gamma- and beta/gamma-hybrid peptides have been synthesized with novel 12/10- and 11/13-mixed helical patterns, respectively. The alpha/gamma-peptides were derived from the dipeptide repeats with alternating arrays of l-Ala and gamma-Caa((l)) (C-linked carbo-gamma-amino acid from d-mannose), which generated a new 12/10-mixed helix, for the first time, without a beta-amino acid. The beta/gamma-peptides made from an alternating arrangement of beta-Caa((x)) (C-linked carbo-beta-amino acid) and gamma-Caa((x)) (C-linked carbo-gamma-amino acid from d-xylose), on the other hand, resulted in an unprecedented 11/13-helix. The secondary structures in these peptides have been ascertained from detailed NMR studies, and CD spectroscopy and molecular dynamics investigations provided additional support for the structures derived.
Sharma
Gangavaram V M
GV
Organic Chemistry Division III, D-211, Discovery Laboratory, and NMR Group, Indian Institute of Chemical Technology, Hyderabad 500,007, India. esmvee@iict.res.in
Jadhav
Vivekanand B
VB
Ramakrishna
Kallaganti V S
KV
Jayaprakash
Pagadala
P
Narsimulu
Kongari
K
Subash
Velaparthi
V
Kunwar
Ajit C
AC
D000596:Amino Acids / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D000596:Amino Acids; D010455:Peptides