Premium
Mixed conformation in C α,α ‐disubstituted tripeptides: X‐ray crystal structures of Z‐Aib‐Dph‐Gly‐Ome and Bz‐Dph‐Dph‐Gly‐Ome
Author(s) -
Pavone V.,
Lombardi A.,
Saviano M.,
Di Blasio B.,
Nastri F.,
Fattorusso R.,
Zaccaro L.,
Maglio O.,
Yamada T.,
Omote Y.,
Kuwata S.
Publication year - 1994
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.360341204
Subject(s) - chemistry , tripeptide , residue (chemistry) , stereochemistry , crystal structure , peptide , crystallography , solid state , organic chemistry , biochemistry
We report here the synthesis and molecular structure in the solid state of fully protected tripeptides containing C α,α ‐diphenylglycine (Dph), namely Z‐Aib‐Dph‐Gly‐OMe (Aib: C α,α ‐dimethylgrycine) and Bz‐Dph‐Dph‐Gly‐OMe. The molecular conformation around the Dph residue, containing two bulky substituents, is fully extended, while the Aib residue, containing two smaller groups on the C α atom, adopts the typical 3 10 /α‐helical conformation. Gly residues, without substituents on the C α atom, show different conformational preferences. Each residue seems to behave, from a conformational point of view, independently from the presence of the other residues, and thus mixed local conformations (folded and extended) are present in the crystals. The nonconventional peptide synthesis, using the Ugi reaction, is also reported. © 1994 John Wiley & Sons, Inc.