National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, No. 199 Ren'ai Road, Industrial Park, Suzhou 215123, China.
Int J Biol Macromol. 2011 Mar 1;48(2):249-55. doi: 10.1016/j.ijbiomac.2010.11.004. Epub 2010 Nov 16.
In this study, the in vitro enzymatic degradation behavior of the regenerated Antheraea pernyi silk fibroin (Ap-SF) three-dimensional (3D) scaffolds and the natural Ap-SF fibers exposed to enzyme solutions of α-chymotrypsin, collagenase IA and protease XIV were investigated. The results indicated that all three proteases could degrade the Ap-SF 3D scaffolds, and the degradation ability was in the order protease XIV>collagenase IA>α-chymotrypsin. The regenerated Ap-SF 3D scaffold could be degraded completely in 18 days when exposed to 1.0 U/ml protease XIV at 37°C, whereas under the same condition, the natural Ap-SF fiber only lost 5.6% of its weight, revealing its long-term degradation characteristics. There were abundant peptides and some free amino acids in the Ap-SF degradation products, but no free alanine. We suggested that the polyalanine block in the regenerated Ap-SF 3D scaffolds had strong resistance to enzyme attack. The proteolytic attack occurred in the non-polyalanine block of Ap-SF. The degradation rate of Ap-SF materials depended on the molecular conformation of Ap-SF, which could be controlled in the manufacturing process.
在这项研究中，研究了再生柞蚕丝素纤维（Ap-SF）三维（3D）支架以及暴露于α-糜蛋白酶、胶原酶 IA 和蛋白酶 XIV 酶溶液中的天然 Ap-SF 纤维的体外酶降解行为。结果表明，所有三种蛋白酶都可以降解 Ap-SF 3D 支架，降解能力的顺序为蛋白酶 XIV>胶原酶 IA>α-糜蛋白酶。当在 37°C 下将 1.0 U/ml 的蛋白酶 XIV 暴露于再生 Ap-SF 3D 支架 18 天时，支架可以完全降解，而在相同条件下，天然 Ap-SF 纤维仅损失其重量的 5.6%，显示出其长期降解的特点。Ap-SF 降解产物中含有丰富的肽和一些游离氨基酸，但没有游离的丙氨酸。我们认为，再生 Ap-SF 3D 支架中的聚丙氨酸块对酶的攻击具有很强的抵抗力。蛋白水解攻击发生在 Ap-SF 的非聚丙氨酸块中。Ap-SF 材料的降解速率取决于 Ap-SF 的分子构象，可以在制造过程中进行控制。
