PMID- 29164193
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180205
LR  - 20180205
IS  - 1463-9084 (Electronic)
IS  - 1463-9076 (Linking)
VI  - 19
IP  - 47
DP  - 2017 Dec 6
TI  - Two-step kinetic model of the self-assembly mechanism for diphenylalanine 
      micro/nanotube formation.
PG  - 31647-31654
LID - 10.1039/c7cp06611b [doi]
AB  - Peptide nanostructures compose a new class of materials that have gained 
      attention due to their interesting properties. Among them, nanotubes of 
      diphenylalanine (FF) and its analogues have been one of the most studied 
      structures in the last few years. Their importance originates from the need to 
      better understand the formation of beta-amyloid fibrils which are associated with 
      Alzheimer's disease. In this work, the FF self-assembly process was probed using 
      time-resolved Raman microscopy. The changes in the Raman spectra are followed 
      over time after injecting water into a FF-film until micro/nanotubes (MNTs) are 
      formed. Specific features of the Raman spectra clearly suggest that FF-molecules 
      after water injection form an intermediate species before forming FF-MNTs. The 
      broad Raman bands observed for the intermediate species suggest the presence of 
      very heterogeneous structures based on FF. The FF-MNTs appear almost 
      instantaneously (detected via the rise of the typical Raman bands of FF-MNTs at 
      761, 1249 and 1426 cm(-1)) after the intermediate structures are formed. This 
      delayed formation of FF-MNTs supports a nucleation process. The formation via 
      nucleation of FF-MNTs is further corroborated by a simulation of the Raman 
      spectra based on a 2-step kinetic model and the respective vibrational Raman 
      modes are identified using Density Functional Theory vibrational calculations. 
      Our results indicate that the driving force for the FF-MNT patterning process is 
      the electric dipole re-orientation originating from the FF dipeptide unit 
      connectivity over time.
FAU - Ishikawa, M S
AU  - Ishikawa MS
AD  - Physikalisch-Chemisches Institut, Im Neuenheimer Feld 229, 
      Ruprecht-Karls-Universitat, D-69120 Heidelberg, Germany. 
      tiago.buckup@pci.uni-heidelberg.de.
FAU - Busch, C
AU  - Busch C
FAU - Motzkus, M
AU  - Motzkus M
FAU - Martinho, H
AU  - Martinho H
FAU - Buckup, T
AU  - Buckup T
LA  - eng
PT  - Journal Article
PL  - England
TA  - Phys Chem Chem Phys
JT  - Physical chemistry chemical physics : PCCP
JID - 100888160
EDAT- 2017/11/23 06:00
MHDA- 2017/11/23 06:01
CRDT- 2017/11/23 06:00
PHST- 2017/11/23 06:00 [pubmed]
PHST- 2017/11/23 06:01 [medline]
PHST- 2017/11/23 06:00 [entrez]
AID - 10.1039/c7cp06611b [doi]
PST - ppublish
SO  - Phys Chem Chem Phys. 2017 Dec 6;19(47):31647-31654. doi: 10.1039/c7cp06611b.