Zwitterionic Polypeptides: Chemoenzymatic Synthesis and Loosening Function for Cellulose Crystals
Zwitterionic Polypeptides: Chemoenzymatic Synthesis and Loosening Function for Cellulose Crystals
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两性离子多肽：化学酶法合成和纤维素晶体的松散功能
DOI：
10.1021/acs.biomac.9b01700
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发表时间：
2020
影响因子：
6.2
通讯作者：
Numata Keiji
中科院分区：
文献类型：
--
作者：
Tsuchiya Kousuke;Yilmaz Neval;Miyamoto Takaaki;Masunaga Hiroyasu;Numata Keiji
合成了一种具有GlyHisGly重复序列的多肽，该多肽含有与纤维素有效相互作用的两性离子结构，用于纤维素晶体的解离。通过化学酶促聚合合成具有GlyHisGly序列的多肽，并对His残基进行后官能化以在侧链上提供咪唑鎓丁酸盐。所得到的两性离子多肽有效地解离束的被囊纤维素纳米晶体，即使当条件是温和的和多肽的浓度低至1-2毫克mL-1。多肽处理也影响了培养的植物细胞的细胞壁的形态，根据原子力显微镜（AFM）的纤维素微纤维网络和无定形多糖层解离。两性离子多肽处理没有改变纤维素纳米晶体的晶体结构。通过使用AFM的力曲线测量对纤维素纳米晶体的机械性质的分析揭示，在用两性离子多肽处理后，纤维素纳米晶体的弹性模量增加，表明纤维素纳米晶体的无定形部分通过与多肽的相互作用而被去除。在能够解离纤维素网络的多肽浓度下，两性离子多肽对植物细胞显示出可忽略的细胞毒性。本研究开发的用于疏松纤维素微纤维/纳米晶体的温和且无细胞毒性的技术对于纤维素在聚合物化学、材料科学和植物生物技术方面的改性具有巨大意义。
A polypeptide with a GlyHisGly repeating sequence containing zwitterionic structures that effectively interact with cellulose was synthesized for dissociation of cellulose crystals. Polypeptide with the GlyHisGly sequence was synthesized by chemoenzymatic polymerization and postfunctionalization of the His residues was performed to afford imidazolium butyrate on the side chains. The resulting zwitterionic polypeptide effectively dissociated bundles of tunicate cellulose nanocrystals, even when the conditions were mild and the concentration of the polypeptide was as low as 1–2 mg mL–1. Polypeptide treatment also affected the morphology of the cell walls in cultured plant cells, and the cellulose microfibril networks and amorphous polysaccharide layer were dissociated according to atomic force microscopy (AFM). The zwitterionic polypeptide treatment did not change the crystal structure of the cellulose nanocrystals. Analysis of the mechanical properties of the cellulose nanocrystals by force curve measurements using AFM revealed that the elastic modulus of the cellulose nanocrystals increased after treatment with the zwitterionic polypeptide, indicating that the amorphous part of the cellulose nanocrystals was removed by interactions with the polypeptide. At a concentration of the polypeptide that enabled the dissociation of the cellulose network, the zwitterionic polypeptide showed negligible cytotoxicity to the plant cells. The mild and noncytotoxic technique for loosening cellulose microfibrils/nanocrystals that was developed in this study has tremendous significance for the modification of cellulose in terms of polymer chemistry, material science, and plant biotechnology.