Design and synthesis of trans-3-aminopyran-2-carboxylic acid (APyC) and α/β-peptides with 9/11-helix.
A new β-amino acid, trans-3-aminopyran-2-carboxylic acid (APyC), was designed and synthesized from (R)-glyceraldehyde derivative and used in the synthesis of α/β-peptides in a 1 : 1 alternating pattern with d-Ala. The presence of oxygen atom at the Cβ(2)-position in APyC was envisaged to provide opportunity for additional interaction. These hybrid peptides have shown the presence of 9/11-helix through extensive NMR and MD studies. The amide protons of d-Ala, in addition to participating in 9-mr H-bonding with CO of succeeding β-residue, were also involved in additional electrostatic interaction with pyran ring oxygen of preceding β-residue, which facilitated further stabilization to the 9/11-mixed helix. The study thus results in a new 'motif' for a 9/11-helix, and the first example from a cyclic β-amino acid.
Organic Chemistry Division III, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500607, India. esmvee@iict.res.in
Gangavaram V M
GV
Sharma
Kodeti Srinivas
KS
Reddy
Shaik Jeelani
SJ
Basha
Kondreddi Ravinder
KR
Reddy
Akella V S
AV
Sarma
D000596:Amino Acids / Q000138:chemical synthesis; D002264:Carboxylic Acids / Q000138:chemical synthesis*; D008958:Models, Molecular; D010455:Peptides / Q000138:chemical synthesis*; D017433:Protein Structure, Secondary; D011714:Pyrans / Q000138:chemical synthesis*; D055672:Static Electricity
C569129:3-aminopyran-2-carboxylic acid; D000596:Amino Acids; D002264:Carboxylic Acids; D010455:Peptides; D011714:Pyrans