Structure, dynamics and applications of peptide-based nanomaterials

Peptide-based nanomaterials have rapidly gained interest over the last 10 years, because of their potential uses in biomedicine, nanotechnology and catalysis. Short peptides can readily self-assemble into ordered structures on the nanometer length scale. The design rules for these constructs are not fully understood yet, which is a key issue in engineering new functional nanomaterials. This thesis discusses how infrared spectroscopy and computational chemistry can contribute to the understanding of structure and dynamics of peptide-based selfassembled systems. Quantum mechanical calculations will be discussed in the light of determining stacking interactions between aromatic peptide amphiphiles and predicting their infrared absorptions bands. Furthermore, in case studies of various peptides, both IR spectroscopy and all-atom MD are demonstrated to be sensitive to small changes in the supramolecular structure as a consequence of variations in the amino acid side chains of the peptides under study. However, currently all-atom MD is still somewhat limited by computational costs and the specific assignments of the bands in IR spectra are not always clear. With a lower level of detail in MD simulations, information relevant to the time and length scales of the process of self-assembly can be obtained. The coarse-grain simulation protocol developed here shows good agreement with experiments in terms of predicting a peptide's propensity to aggregate and can reproduce morphological features of self-assembled systems. Finally, these peptide-based materials are applied in encapsulating an enzyme active site mimic that is of relevance for the cheap, environmentally friendly production of hydrogen as a fuel. Using time-resolved infrared spectroscopy it is shown that the hydrogel environment formed by a short, amphiphilic peptide protected the enzyme 15 mimic both from degradation by oxygen and UV irradiation. This type of peptide scaffolding for hydrogenase mimics has potential in creating an artificial enzyme for the reversible oxidation of hydrogen.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral-pg

Grantor dc:publisher.institution

University of Strathclyde

Year dc:date.issued

2013

Author dc:creator

• Frederix, Pim W. J. M.

DOI

10.48730/d1zt-ee17

Identifier

T13585

OAI identifier oai:identifier

oai:strathclyde:f7623c670