| Abstract
| - Poly(asparagine) (pAsn) at 0.1wt % in the presence of dodecyltrimethylammonium bromide (DTAB) andpentaoxyethylene octyl ether (C8E5) at 1:1 molar ratio leads to the formation of mixed DTAB/C8E5 micelle-like aggregates onto the polypeptide as a total surfactant critical association concentration (cac) is reached,as revealed by surface tension measurements and NMR chemical shifts. Two-dimensional nuclearOverhauser enhancement spectroscopy (NOESY) capable of revealing spatial relationships among proximalprotons has been performed on the pAsn−DTAB−C8E5−water system to study structural details of thesurfactant−polypeptide aggregates. NOESY cross-peaks at sample temperature of 298.15 K indicate thatthe polypeptide interacts with the DTAB/C8E5 micelle-like aggregates. The NOE intermolecular effectsalso show direct interactions between surfactant and polypeptide in the pAsn−DTAB−water system,whereas no interaction has been revealed in the pAsn−C8E5−water system. Furthermore, the experimentalevidence suggest that the DTAB−polypeptide complex is mainly driven by the polar attraction betweenthe two molecules.
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