Physical Gelation of α-Helical Copolypeptides

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• 作者：Charlotte D. Vacogne ; Michael Schopferer ; Helmut Schlaad
• 刊名：Biomacromolecules
• 出版年：2016
• 出版时间：July 11, 2016
• 年：2016
• 卷：17
• 期：7
• 页码：2384-2391
• 全文大小：611K
• 年卷期：0
• ISSN：1526-4602

文摘

Owing to its rod-like α-helical secondary structure, the synthetic polypeptide poly(γ-benzyl-l-glutamate) (PBlG) can form physical and thermoreversible gels in helicogenic solvents such as toluene. The versatility of PBlG can be increased by introducing functionalizable comonomers, such as allylglycine (AG). In this work we examined the secondary structure of PBlG and a series of statistical poly(γ-benzyl-l-glutamate-co-allylglycine) copolypeptides, varying in composition and chain length, by circular dichroism (CD), Fourier-transform infrared (FTIR) and Raman spectroscopy, and wide-angle X-ray scattering (WAXS). The secondary structure of PBlG and the copolypeptides presented dissimilarities that increased with increasing AG molar fraction, especially when racemic AG units were incorporated. The physical gelation behavior of these copolypeptides was analyzed by temperature-sweep ¹H NMR and rheological measurements. The study revealed that both copolypeptide composition and chain length affected secondary structure, gelation temperature, and gel stiffness.