We report the synthesis of zwitterionic homopolypeptides and block copolypeptides bearing carboxybetaine and sulfobetaine (CB and SB) via combining γ-propargyl-L-glutamate NCA polymerization with efficient Huisgen's click reaction. The zwitterionic homopolypeptides adopted versatile chain conformations upon varying the solution pH, depending on the chain length and functional group. The zwitterionic homopolypeptides with a degree of polymerization (DP) of 60 adopted stable α-helical conformation due to their elongated side-chain, whereas the short ones (DP = 20) adopted different conformations at varying solution pH. Their interactions with proteins depend on the chain conformation and zwitterionic group. The short one bearing SB exhibited very low interactions with lysozyme and myoglobin due to its coil and zwitterionic nature. A preliminary study showed that the zwitterionic block copolypeptides self-assemble to form vesicles with tunable molecular packing and solution behavior. These biodegradable/biocompatible, zwitterionic polypeptides may be promising materials in many applications such as non-fouling coatings and drug delivery.

中文翻译：

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带有羧基甜菜碱和磺基甜菜碱的两性离子多肽：合成，自组装及其与蛋白质的相互作用†

我们报告通过结合γ-炔丙基-L合成两性离子同多肽和嵌段共多肽，它们含有羧基甜菜碱和磺基甜菜碱（CB和SB）-谷氨酸NCA聚合，具有有效的Huisgen的点击反应。两性离子均多肽根据链长和官能团的不同，在改变溶液pH值时采用了通用的链构象。聚合度（DP）为60的两性离子均多肽由于其细长的侧链而具有稳定的α-螺旋构象，而短的两性离子均肽（DP = 20）在不同的溶液pH下具有不同的构象。它们与蛋白质的相互作用取决于链构象和两性离子基团。由于其卷曲和两性离子性质，一个短的SB SB与溶菌酶和肌红蛋白的相互作用极低。初步研究表明，两性离子嵌段共多肽可自组装形成具有可调分子堆积和溶液行为的囊泡。