家蚕纺丝管道与蚕丝力学性能定向改良

The "bioforging" process experienced by silk proteins in silkworm spinning duct imparts mechanical properties to silk fibers. Although it has been found that metal ions, pH, and chitin in the spinning duct regulate the "bio-forging" process and affect the conformational transition of silk proteins, the systematic effects of these factors on the mechanical properties of silk fiber are still not clear. Our previous works found that the mechanical properties of silk fiber can be improved by genetic manipulation of ion transporting proteins in silkworm spinning duct. As a result, this project intends to study the structure, metal ionic components of silkworm spinning duct, and the function of spinning duct in "bioforging" process. An interaction network model between metal ion and silk mechanical performance will be established to screen and identify the determinants for silk mechanical properties. Considering with the demands for high-performance silk fibers, this project will rationally design and assemble the optimal determinants into the silkworm through genetic manipulation. The goal for this project is to achieve the directional modification of silk fiber mechanical properties. This project is expected to provide new theoretical and experimental basis for the clarification of the mechanism for animal silk fiber formation and the development of high-performance silk fibers.

蚕丝蛋白在家蚕纺丝管道中经历的“生物锻造”过程赋予了蚕丝纤维力学性能。尽管目前已经发现纺丝管道中各种金属离子、pH及几丁质会调节丝蛋白“生物锻造”过程，影响蚕丝构象转变，但这些因素对丝纤维力学性能决定的系统性作用并未明确。申请人前期研究发现对家蚕纺丝管道中的离子转运蛋白进行遗传操作能实现蚕丝力学性能的改良。鉴于此，本项目拟研究家蚕纺丝管道的结构、金属离子组分及其在丝蛋白“生物锻造”过程中的功能，建立各种金属离子与蚕丝结构、性能的相互关系网络模型，从而筛选和鉴定蚕丝力学性能决定因子，最后结合需求，通过遗传操作的方式理性设计并组装优选因子，实现对蚕丝纤维力学性能的定向改良。通过本项目的实施，预期将为动物丝纤维形成机制的阐明和高性能丝纤维的开发提供新的理论和实验依据。

蚕丝蛋白在家蚕纺丝管道中经历的“生物锻造”过程赋予了蚕丝纤维力学性能。尽管目前已经发现纺丝管道中各种金属离子、pH及几丁质会调节丝蛋白“生物锻造”过程，影响蚕丝构象转变，但这些因素对丝纤维力学性能决定的系统性作用并未明确。本项目研究了家蚕纺丝管道的结构、金属离子组分及其在丝蛋白“生物锻造”过程中的功能，建立了金属离子与蚕丝结构、性能的相互关系网络，筛选和鉴定了一批蚕丝力学性能决定因子，成功组装并顺利获得了4种性能显著提升的新型蚕丝纤维，最后针对国家对高强度高刚性材料的具体需求，通过遗传操作的方式成功组装优选因子（铁蛋白基因），获得了高强度高刚度的新型“铁蚕丝”纤维素材，其强度较对照提升76%，刚度提升157%，实现了蚕丝纤维力学性能的定向改良。通过本项目的实施，为动物丝纤维形成机制的阐明和高性能丝纤维的开发提供了新的理论和实验依据。