New insight into the mechanism of in vivo fibroin self-assembly and secretion in the silkworm, Bombyx mori
New insight into the mechanism of in vivo fibroin self-assembly and secretion in the silkworm, Bombyx mori
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家蚕体内丝素蛋白自组装和分泌机制的新见解
DOI：
10.1016/j.ijbiomac.2020.12.132
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发表时间：
2021-02-01
影响因子：
8.2
通讯作者：
Zhao, Aichun
中科院分区：
文献类型：
--
作者：
Hao, Zhanzhang;Long, Dingpei;Zhao, Aichun
家蚕的丝素由丝素重链（Fib - H）、丝素轻链（Fib - L）和P25组成。丝素重链具有两侧为亲水性N端和C端结构域（分别为NTD和CTD）的疏水中间重复序列。然而，每种多肽在蚕丝加工过程中各自的作用在很大程度上仍然未知。在此，为了在丝腺中选择性表达不同的荧光融合蛋白，构建了一系列带有不同融合基因表达盒的转基因家蚕。通过观察和分析这些蛋白质在丝腺和茧丝中的移动和分布，研究了蚕丝加工过程中不同成分的作用。数据表明，亲水性NTD分布在胶束表面，提供足够的静电斥力以防止丝蛋白过早结晶。亲水性CTD == Ls（“==”表示二硫键）位于胶束内层，以控制大胶束的溶解性。此处呈现的结果阐明了家蚕体内蚕丝加工的潜在机制。这对人工纺丝技术、新型丝生物材料和丝腺表达系统的开发具有重要意义。（C）2020爱思唯尔有限公司。保留所有权利。
Fibroin of the silkworm consists of fibroin heavy chain (Fib-H) with hydrophobic intermediate repeats flanked by hydrophilic N and C terminal domains (NTD and CTD, respectively), fibroin light chain (Fib-L), and P25. However, the respective roles of each polypeptide in silk processing remain largely unknown. Here, a series of transgenic silkworms with different fusion gene expression cassettes were created in order to selectively express different fluorescent fusion proteins in silk glands. The roles of different components in silk processing were investigated via observing and analyzing the movement and distribution of these proteins in the silk gland and in cocoon silk. The data showed that hydrophilic NTDs were distributed on the surface of micelles, providing sufficient electrostatic repulsion to prevent premature crystallization of silk proteins. Hydrophilic CTD==Ls ("==" represents the disulfide bond) were located on the inner layer of micelles to control the solubility of large micelles. The results presented here elucidated the underlying mechanisms of silkworm silk processing in vivo. This is significant for the development of artificial spinning technology, novel silk biomaterials, and silk gland expression systems. (C) 2020 Elsevier B.V. All rights reserved.