South African Journal of Chemistry
On-line version ISSN 1996-840X
MARTARI, Marco and SANDERSON, Ronald D.. Critical self-assembly concentration of bolaamphiphilic peptides and peptide hybrids determined by fluorescence measurements. S.Afr.j.chem. (Online) [online]. 2008, vol.61, pp. 47-52. ISSN 1996-840X.
The study of the self-assembly properties of peptides and proteins is important for the understanding of molecular recognition processes and for the rational design of functionalbiomaterials. Novel bolaamphiphilic peptides and peptide hybrids incorporating non-natural aminoacids were designed around a model lysine/leucine-rich peptide with the intention to study their self-assembly behaviour. Steady-state fluorescence measurements using pyrene as fluorescent probe were adapted to the determination of the critical self-assembly concentrations (CSACs) of these amphiphilic peptides and peptide hybrids. Different experimental conditions were studied. The morphology of the peptide aggregates was evaluated by scanning electron microscopy (SEM). Concentration and pH have been revealed to play a key role in the control of the process. Peptides presented different three-dimensional supramolecular arrangements that were correlated with their aminoacid compositions (specifically considering the presence of tyrosine and proline) and CSAC values.
Keywords : Peptide aggregation; self-assembly; critical self-assembly concentration; fluorescence; pyrene.