Structural Stability of Polypeptide Nanofilms under Extreme Conditions

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• 作者：Bingyun Li ; Joshua Rozas ; and Donald T. Haynie
• 刊名：Biotechnology Progress
• 出版年：2006
• 出版时间：February 2006
• 年：2006
• 卷：22
• 期：1
• 页码：111 - 117
• 全文大小：740K
• 年卷期：v.22,no.1(February 2006)
• ISSN：1520-6033

文摘

Self-assembly of designed peptides is a promising area of biomaterials research and development.Here, polypeptide nanofilms have been prepared by electrostatic layer-by-layer self-assembly(LBL) of cysteine (Cys)-containing 32mers designed to be oppositely charged at neutral pH,and structural stability of the films has been probed by subjecting them to various extremephysical and chemical conditions. The results suggest that although electrostatic attraction playsa key role in strengthening polypeptide films, stability is inversely related to absolute net chargeof the supramolecular complex. This behavior is similar to the typical behavior of small globularproteins. Film structure is very stable in organic solvent and, when dehydrated, at extremetemperatures. Such stability is in marked contrast to the behavior of proteins, which tend todenature under comparable conditions. Similar to proteins, peptide nanofilms cross-linked bydisulfide (S-S) bonds are considerably stronger than films stabilized by electrostatic, van derWaals, or hydrophobic interactions alone. This effect is particularly evident at extremes of pHand at elevated temperature when the film is hydrated. These results, the great variety of possiblepeptide structures, the inherent biocompatibility of L-amino acids, and current applications ofthin films in commercial products together suggest that polypeptide films are promising for thedevelopment of new or enhanced products in food technology, drug delivery and medical devicecoatings, and biomaterials.