Extended Frequency Range Depolarized Light Scattering Study of N-Acetyl-leucine-methylamide鈥揥ater Solutions

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• 作者：Stefania Perticaroli ; Lucia Comez ; Marco Paolantoni ; Paola Sassi ; Assunta Morresi ; Daniele Fioretto
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：August 10, 2011
• 年：2011
• 卷：133
• 期：31
• 页码：12063-12068
• 全文大小：864K
• 年卷期：v.133,no.31(August 10, 2011)
• ISSN：1520-5126

文摘

We have studied the influence of the amphiphilic model peptide N-acetyl-leucine-methylamide (NALMA) on the dynamics of water using extended frequency range depolarized light scattering (EDLS), between 0.3 GHz and 36 THz. This technique allowed us to separate solute from solvent dynamics and bulk from hydration water, providing both characteristic times and relative fractions. In the temperature range 5鈥?5 掳C, a retardation factor from 9 to 7 is found for water hydrating NALMA. Moreover, in the same range, a hydration number from 62 to 50 is observed, corresponding to more than two hydration layers. This strong perturbation suggests the existence of a collective effect of amphiphilic molecules on surrounding water molecules.