The internal dynamic modes of charged self-assembled peptide fibrils.
Photon correlation spectroscopy is used to study the internal dynamics of self-assembled charged peptide fibrils. Short neutral and charged polymeric aggregates have diffusive modes due to whole macromolecular motion. For long semiflexible fibrils the logarithm of the intermediate scattering function follows a q(2)t(3/4) scaling at long times consistent with a Kratky-Porod free energy and preaveraged Oseen hydrodynamics. Persistence lengths on the order of micrometers are calculated for the peptide fibrils consistent with estimates from the liquid-crystalline phase behavior. Fibril diameters (5-35 nm) calculated from the initial decay of the correlation functions are in agreement with transmission electron microscopy measurements.
Carrick
L
L
Tassieri
M
M
Waigh
T A
TA
Aggeli
A
A
Boden
N
N
Bell
C
C
Fisher
J
J
Ingham
E
E
Evans
R M L
RM
D000465:Algorithms; D044085:Microfluidics; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D036103:Nanotechnology; D010446:Peptide Fragments / Q000737:chemistry* / Q000648:ultrastructure; D012542:Scattering, Radiation; D013816:Thermodynamics
D010446:Peptide Fragments