文献类型：期刊文献

英文题名：Micellization activity of the natural lipopeptide [Glui, Asp5] surfactin-C15 in aqueous solution

作者：Zou, Aihua[1,2]; Liu, Jing[1]; Garamus, Vasil M.[2]; Yang, Ying[1]; Willumeit, Regine[2]; Mu, Bozhong[1]

机构：[1] State Key Laboratory of Bioreactor Engineering, Institute of Applied Chemistry, East China University of Science and Technology, Shanghai 200237, China; [2] GKSS Research Center, Max-Planck-Str.1, 21502 Geesthacht, Germany

年份：2010

卷号：114

期号：8

起止页码：2712

外文期刊名：Journal of Physical Chemistry B

收录：EI(收录号：20101012761950)

语种：英文

外文关键词：Surface tension - High resolution transmission electron microscopy - Micelles - Agglomeration - Molecules - Solutions - Dichroism - Neutron scattering - Air - Phase interfaces

摘要：Surface tension, small angle neutron scattering (SANS), freeze-fracture transmission electron microscopy (FF-TEM), and circular dichroism (CD) have been used to study the self-aggregation properties of the natural lipopeptide [Glu1, Asp5] surfactin-C15 in 0.01 M phosphate buffer solution (PBS) at pH 7.4. It has been found that the critical micelle concentration (cmc) of surfactin is 1.54 × 10-5 M, the surface tension at the cmc (σcmc) is 27.7 mN/m, and the area per molecule at the air-water interface is 107.8 ?2. Surfactin molecules adopt a β-sheet conformation already at low concentrations. This feature probably makes it surface-active at such low concentrations. From SANS and FF-TEM results, it is seen that surfactin exhibits a strong selfassembly ability to form sphere-like micelles and some larger aggregates even at the rare low concentration. The aggregation number of sphere-like micelles is much smaller than that for conventional surfactants of similar alkyl chain length. ? 2010 American Chemical Society.