Premium
Effect of methylene group insertions on the structural rigidity of Aib containing helices
Author(s) -
Duley Anju,
Gowda Vasantha,
Ganjiwale Anjali,
Raghothama Srinivasarao,
Ramanathan Gurunath
Publication year - 2015
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.22691
Subject(s) - chemistry , methylene , alanine , structural rigidity , stereochemistry , peptide , residue (chemistry) , circular dichroism , glycine , aminobutyric acid , amino acid , amino acid residue , crystallography , peptide sequence , organic chemistry , biochemistry , mathematics , geometry , receptor , gene
ABSTRACT Nonprotein amino acids are being extensively used in the design of synthetic peptides to create new structure mimics. In this study we report the effect of methylene group insertions in a heptapeptide Boc‐Ala 1 ‐Leu 2 ‐Aib 3 ‐Xxx 4 ‐Ala 5 ‐Leu 6 ‐Aib 7 ‐OMe which nicely folds into a mixed 3 10 ‐/α‐helical structure when Xxx= Ala. Analogs of this peptide have been made and studied by replacing central Xxx 4 residue with Glycine (α‐residue), β‐Alanine (β‐Αla), γ‐aminobutyric acid (Gaba), and ε‐aminocaproic acid (ε‐Aca). NMR and circular dichroism were used to study the solution structure of these peptides. Crystals of the peptides containing alanine, β‐Αla, and Gaba reveal that increasing the number of central methylene (‐CH 2 ‐) groups introduces local perturbations even as the helical structure is retained. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 720–732, 2015.