Biopolymers: Polypeptide Self-assembly and dynamics

This part refers to results from recent efforts on understanding the hierarchical self-assembly and dynamics of polypeptides with the aid of different NMR techniques (group of Prof. H.W. Spiess), X-ray scattering and dielectric spectroscopy. The concerted application of these techniques shed light to the origin of glass transition, the persistence of the α-helical peptide secondary motif and the effects of topology and packing on the type and persistence of secondary structures. With respect to the freezing of the dynamics at the liquid-to-glass temperature it was found that the origin of this effect is a network of broken hydrogen bonds. The presence of defected hydrogen bonded regions reduces the persistence length of α-helices. Block copolypeptides provide means of manipulating both the type and persistence of peptide secondary structures.

Collaborators: H. Iatrou (Univ. of Athens), R. Graf, H.W. Spiess (MPI-P)

Recent representative publications (2010-2013)

[1] A. Gitsas, G. Floudas, M. Mondeshki, I. Lieberwirth, H.W. Spiess, H. Iatrou, N. Hadjichristidis,

 “Hierarchical self-assembly and dynamics of a miktoarm star chimera composed of poly(γ-benzyl-L-glutamate), polystyrene and polyisoprene”,

 Macromolecules 43, 1874, 2010.

[2] M. Mondeshki, H.W. Spiess, T. Aliferis, H. Iatrou, N. Hadjichristidis, G. Floudas, 

“Hierarchical self-assembly in diblock copolypeptides of poly(γ-benzyl-L-glutamate) with Poly(L-leucine) and poly(O-benzyl-L-tyrosine)”, 

Europ. Polymer Journal  2011.

[3] R. Graf, H. W. Spiess, G. Floudas, H.-J. Butt, M. Gkikas, H. Iatrou, 

“Conformational transitions of Poly(L-proline) in copolypeptides with Poly(γ-benzyl-L-glutamate) induced by packing”, 

Macromolecules 45, 9326, 2012.