Silk consists of two proteins called fibroin and sericin. While fibroin is used in the textile industry and has various biomaterial applications, sericin has been considered as waste material until recently. Sericin is a multicomponent protein and it has important properties such as biocompatibility, biodegradability, cryoprotectivity, and antioxidant. Sericin from silkworm cocoons can be obtained by chemical, enzymatic, and heat treatment methods. However, sericin obtained with these treatment methods is not of consistent and high quality. Moreover, the exposure of sericin to harsh conditions during extraction leads to inconsistencies in the composition and structure of the sericin obtained. The inconsistencies in sericin structure and composition decrease application of sericin as a biomaterial. Here, we produce a sericin-like protein (Ser4mer) with native sequence of sericin encoding four repeats of the conserved 38 amino acid motif recombinantly in Escherichia coli and characterize its structural properties. Ser4mer protein shows similar structure to native sericin and higher solubility than previously obtained recombinant sericin-like proteins. Recombinant production of a soluble sericin-like protein will significantly expand its applications as a biomaterial. In addition, recombinant production of silk proteins will allow us to understand sequence–structure relationships in these proteins.

中文翻译：

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一种新型丝胶样蛋白的克隆、表达和表征

丝绸由两种蛋白质组成，称为丝心蛋白和丝胶。虽然丝心蛋白用于纺织工业并具有各种生物材料应用，但丝胶蛋白直到最近才被视为废料。丝胶是一种多组分蛋白质，具有生物相容性、生物降解性、冷冻保护性和抗氧化性等重要特性。蚕茧中的丝胶可以通过化学、酶和热处理方法获得。然而，通过这些处理方法获得的丝胶蛋白质量并不稳定。此外，在提取过程中将丝胶暴露于苛刻条件会导致所得丝胶的组成和结构不一致。丝胶蛋白结构和组成的不一致减少了丝胶蛋白作为生物材料的应用。这里，大肠杆菌及其结构特性的特征。Ser4mer 蛋白显示出与天然丝胶蛋白相似的结构和比先前获得的重组丝胶蛋白样蛋白更高的溶解度。可溶性丝胶蛋白样蛋白的重组生产将显着扩大其作为生物材料的应用。此外，丝蛋白的重组生产将使我们能够了解这些蛋白质中的序列-结构关系。