Peptide Nanospheres Self-Assembled From a Modified β-Annulus Peptide of Sesbania Mosaic Virus

A novel beta-annulus peptide of Sesbania mosaic virus bearing an FKFE sequence at the C terminus was synthesized, and its self-assembling behavior in water was investigated. Dynamic light scattering and transmission electron microscopy showed that the beta-annulus peptide bearing an FKFE sequence self-assembled into approximately 30 nm nanospheres in water at pH 3.8, whereas the beta-annulus peptide without the FKFE sequence afforded only irregular aggregates. The peptide nanospheres possessed a definite critical aggregation concentration (CAC526 mu M), above which the size of nanospheres were nearly unaffected by the peptide concentration. The formation of peptide nanospheres was significantly affected by pH; the peptide did not form any assemblies at pH 2.2, whereas larger aggregates were formed at pH 6.4-11.6. (C) 2015 Wiley Periodicals, Inc.