Portal de Periódicos da CAPES

Self-Assembly and Acid-Responsive Behavior of Three Amphiphilic Peptides

2015; Peking University Press; Volume: 31; Issue: 4 Linguagem: Inglês

10.3866/pku.whxb201503031

1000-6818

Ju Liang, LAI Dan-Yu, WU Wen-Lan, LI Guo-Zhi, Junbo Li, FANG Cai-Lin,

Polydiacetylene-based materials and applications

Three amphiphilic peptides containing KKGRGDS as hydrophilic heads and VVVVVV, C12, and FAFAFAas hydrophobic tails (VVVVVVKKGRGDS (AP1), C12KKGRGDS (AP2), FAFAFAKKGRGDS (AP3)) were designed and prepared using the standard solid-phase peptide synthesis (SPPS) technique. Three peptides assembled into spherical micelles under neutral conditions (pH 7.0) with a size of ~30 nm determined by transmission electron microscope (TEM). Dynamic light scattering (DLS) tests showed that their size distributions were uniform and narrow. In dilute hydrochloric acid (pH 5.0), peptideAP1 presented a sharp acid- dependent demicellization transition, with no assembled particles found by TEM and no DLS peak in the range 1-1000 nm. However, the micellar structures of the amphiphilic peptidesAP2 andAP3 did not disappear at pH 5.0. TEM results showed that AP2 assembly appeared through aggregation and the shape of AP3 micellar particles became non-spherical or irregular. AP2 assembly at pH 5.0 showed a multiple peak distribution and AP3 assembly showed a broad peak distribution in DLS, consistent with the TEM results. The changes in