Effect of chain topology on the self-organization and dynamics of block copolypeptides: from diblock copolymers to stars.
The effect of chain topology on (i) the peptide secondary structure, (ii) the nanophase self-assembly, and (iii) the local segmental and global peptide relaxations has been studied in a series of model diblock and 3-arm star copolypeptides of poly(epsilon-carbobenzyloxy-L-lysine) (PZLL) and poly(gamma-benzyl-L-glutamate) (PBLG) with PZLL forming the core. Diblock copolypeptides are nanophase separated with PBLG and PZLL domains comprising alpha-helices packed in a hexagonal lattice. Star copolypeptides are only weakly phase separated, comprising PBLG and PZLL alpha-helices in a pseudohexagonal lattice. Phase mixing has profound consequences on the local and global dynamics. The relaxation of the peptide secondary structure speeds up, and the helix persistence length is further reduced in the stars, signifying an increased concentration of helical defects.
Department of Physics, University of Ioannina, Post Office Box 1186, 45110 Ioannina, Greece. gfloudas@cc.uoi.gr
A
A
Gitsas
G
G
Floudas
M
M
Mondeshki
H-J
HJ
Butt
H W
HW
Spiess
H
H
Iatrou
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N
Hadjichristidis
D010455:Peptides / Q000737:chemistry*; D011099:Polyglutamic Acid / Q000031:analogs & derivatives; D011107:Polylysine / Q000031:analogs & derivatives; D011108:Polymers / Q000737:chemistry*; D017433:Protein Structure, Secondary
D010455:Peptides; D011108:Polymers; C003172:poly-gamma-benzyl-L-glutamate; D011107:Polylysine; D011099:Polyglutamic Acid; C038295:poly(N(epsilon)-benzyloxycarbonyl-L-lysine)