Schmuck Benjamin, Greco Gabriele, Shilkova Olga, Rising Anna
Department of Medicine Huddinge, Karolinska Institutet, Neo, 141 83 Huddinge, Sweden.
Department of Animal Biosciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden.
ACS Omega. 2024 Oct 7;9(41):42423-42432. doi: 10.1021/acsomega.4c06031. eCollection 2024 Oct 15.
Spiders can produce up to seven different types of silk, each with unique mechanical properties that stem from variations in the repetitive regions of spider silk proteins (spidroins). Artificial spider silk can be made from mini-spidroins in an all-aqueous-based spinning process, but the strongest fibers seldom reach more than 25% of the strength of native silk fibers. With the aim to improve the mechanical properties of silk fibers made from mini-spidroins and to understand the relationship between the protein design and the mechanical properties of the fibers, we designed 16 new spidroins, ranging from 31.7 to 59.5 kDa, that feature the globular spidroin N- and C-terminal domains, but harbor different repetitive sequences. We found that more than 50% of these constructs could be spun by extruding them into low-pH aqueous buffer and that the best fibers were produced from proteins whose repeat regions were derived from major ampullate spidroin 4 (MaSp4) and elastin. The mechanical properties differed between fiber types but did not correlate with the expected properties based on the origin of the repeats, suggesting that additional factors beyond protein design impact the properties of the fibers.
蜘蛛能产生多达七种不同类型的丝，每种丝都具有独特的机械性能，这些性能源于蜘蛛丝蛋白（蛛丝蛋白）重复区域的变化。人工蜘蛛丝可以通过全水相纺丝工艺由微型蛛丝蛋白制成，但最强的纤维强度很少能超过天然丝纤维强度的25%。为了提高由微型蛛丝蛋白制成的丝纤维的机械性能，并了解蛋白质设计与纤维机械性能之间的关系，我们设计了16种新的蛛丝蛋白，分子量在31.7至59.5 kDa之间，它们具有球状蛛丝蛋白的N端和C端结构域，但含有不同的重复序列。我们发现，将其中超过50%的构建体挤出到低pH值的水性缓冲液中即可纺丝，并且最好的纤维是由重复区域源自大壶腹状腺蛛丝蛋白4（MaSp4）和弹性蛋白的蛋白质制成的。不同类型纤维的机械性能有所不同，但与基于重复序列来源预期的性能不相关，这表明除了蛋白质设计之外，还有其他因素影响纤维的性能。
