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Design, synthesis, conformational and membrane ion transport studies of proline‐adamantane hybrid cyclic depsipeptides
Author(s) -
Karle Isabella L.,
Ranganathan Darshan,
Kumar Mittapalli Gopi,
Nagaraj Ramakrishnan
Publication year - 2008
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20903
Subject(s) - chemistry , depsipeptide , adamantane , peptide , cyclic peptide , stereochemistry , diamondoid , membrane , crystallography , ring size , ion , molecule , ring (chemistry) , biochemistry , organic chemistry
The design, synthesis, conformational, crystallographic, and ion transport studies of 30‐membered, proline containing depsipeptides that incorporate the rigid low molecular weight lipophilic adamantane (Adm) building blocks are reported. The adamantyl groups provide the desired membrane permeability and conformational constraint for efficient transport in lipid membranes. The novel cyclic depsipeptides are: c[AdmC(O)Pro OCH 2 CHRNHC(O)ProC(O) AdmC(O)ProC(O)NHCHRCH 2 OProC(O)] where RH for A and RCONHAdm for B . Crystal structure analysis of A established that the two peptide segments are identical in formula and in conformation and that the peptides are bonded to the interleaving Adm at the 1 and 3 positions. However, the complete ring is highly asymmetric in shape since bonds for both Peptide‐Adm‐Peptide segments have the syn‐anti motif. Torsional angles for the connecting bonds to Adm are −162°, +71° and −169°, −48°. The irregular clamshell shape of the molecule has three internal CO moieties directed in a manner that could provide three Na + O ligands. While A exhibited negligible transport of Na + ions across membranes, peptide B endowed with two additional adamantanes in the periphery did transport Na + ions from outside to inside. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 471–478, 2008. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com