R. Balaji Rao

Comparison of helix-stabilizing effects of α,α-dialkyl glycines with linear and cycloalkyl side chains

The ability of \alpha, \alpha -di-n-alkyl glycines with linear and cyclic alkyl side chains to stabilize helical conformations has been compared using a model heptapeptide sequence. The conformations of five synthetic heptapeptides (Boc–Val–Ala–Leu–Xxx–Val–Ala–Leu–OMe,

Conformational choice at α,α-Di-n-propylglycine residues: Helical or fully extended structures?

Xxx = Ac_8c, Ac_7c, Aib, Dpg ,and Deg, where Ac_8c

Stereochemistry of linking segments in the design of helix-helix motifs in peptides. Crystallographic comparison of a glycyl- dipropylglycyl-glycyl segment in a tripeptide and a 14-residue peptide

= 1-aminocyclooctane-1-carboxylic acid,

Solution conformation of a tetradecapeptide stabilized by two di-n-propyl glycine residues.

Ac_7c

Peptide Design. Structural Evaluation of Potential Nonhelical Segments Attached to Helical Modules

= 1-aminocycloheptane-1-carboxylic acid, Aib = a-aminoisobutyric acid, Dpg = \alpha, \alpha -di-n-propyl glycine, Deg = \alpha, \alpha -din- ethyl glycine) have been investigated. In crystals, helical conformations have been demonstrated by x-ray crystallography for the peptides, R–Val–Ala–Leu–Dpg–Val–Ala–Leu–OMe, (R = Boc and acetyl). Solution conformations of the five peptides have been studied by

Peptide helices with pendant cycloalkane rings. Characterization of conformations of 1-aminocyclooctane-1-carboxylic acid (Ac8c) residues in peptides

^1H-nmr

Context-dependent conformation of diethylglycine residues in peptides

. In the apolar solvent

Conformation of di-n-propylglycine residues (Dpg) in peptides: crystal structures of a type I′β-turn forming tetrapeptide and an α-helical tetradecapeptide

CDCl_3

Crystal structure of tert-butyloxycarbonyl-a-aminoisobutyryl-C-a,a-di-n-butylglycyl-methyl ester, C20H38N2O5

, all five peptides favor helical conformations in which the NH groups of residues 3–7 are shielded from the solvent. Successive

Structure of Matter Peptide Design: Crystal Structure of a Helical Peptide Potentially Nonhelical Amino USA Module Attached to a

N_iH \leftrightarrow N_{i+1}H