𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Synthesis and conformational studies of peptides containing TOAC, a spin-labelled Cα,α-disubstituted glycine

✍ Scribed by Claudio Toniolo; Ezio Valente; Fernando Formaggio; Marco Crisma; Giuseppe Pilloni; Carlo Corvaja; Antonio Toffoletti; Gary V. Martinez; M. Paul Hanson; Glenn L. Millhauser; Clifford George; Judith L. Flippen-Anderson

Book ID
105360081
Publisher
John Wiley and Sons
Year
1995
Tongue
English
Weight
970 KB
Volume
1
Category
Article
ISSN
1075-2617

No coin nor oath required. For personal study only.

✦ Synopsis

A variety of host L-alanine homo-peptides (to the pentamer) containing one or two spin-labelled TOAC (2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid) residues were synthesized by solution methods and fully characterized. The conformational features of the terminally blocked, doubly spin-labelled TOAC-(Ala)2-TOAC-Ala-pentapeptide were examined in the crystal state by X-ray diffraction and in solution using a combination of techniques (Fourier transform infrared, circular dichroism, cyclic voltammetry and electron spin resonance) in comparison with singly labelled shorter peptides. The 3(10)-helical structure of the pentapeptide, promoted by the two C alpha, alpha-disubstituted glycines under favourable experimental conditions, allows an interaction to take place between the two nitroxide TOAC side chains spaced by one turn of the helix. Taken together, these results suggest that TOAC is an excellent probe for exploring bends and helices in doubly labelled peptides.

📜 SIMILAR VOLUMES

Peptides from chiral Cα,α-disubstituted
Peptides from chiral Cα,α-disubstituted glycines. Synthesis and conformational analysis of homochiral (αMe) Leu / Ala model peptides
✍ J. Kamphuis; W. H. J. Boesten; H. E. Schoemaker; A. Aubry; D. Bayeul; A. Dautant 📂 Article 📅 2010 🏛 Elsevier Science 🌐 English ⚖ 635 KB

## Abstract Homochiral (αMe)Leu/Ala and Leu/Ala model peptides were synthesized by solution methods and fully characterized. A solution conformational analysis of the tripeptides was carried out using FT‐IR absorption and ^1^H NMR. The crystal‐state structure of Z‐D‐(αMe)Leu‐(D‐Ala)~2~‐OMe monohydr

Synthesis of the First Axially Dissymmet
Synthesis of the First Axially Dissymmetric, Cα,α-Disubstituted Glycine Containing a Crown Ether Receptor, and the Conformational Preferences of a Model Peptide
✍ Jean-Paul Mazaleyrat; Yolaine Goubard; Maria-Vittoria Azzini; Michel Wakselman; 📂 Article 📅 2002 🏛 John Wiley and Sons 🌐 English ⚖ 598 KB

Keywords: Atropoisomeric amino acids / Axial chirality / C α,α -disubstituted glycine / Crown compounds / Side-chain modified amino acids Racemic and enantiomerically enriched N α -protected methyl 6-amino-1,11-(20-crown-6)-6,7-dihydro-5H-dibenzo[a,c]cycloheptene-6-carboxylates (Boc-[20-C-6]-Bip-OMe