Orb weaver glycoprotein is a smart biological material, capable of repeated adhesion cycles
Orb weaver glycoprotein is a smart biological material, capable of repeated adhesion cycles
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DOI：
10.1007/s00114-019-1607-z
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发表时间：
2019-04-01
影响因子：
1.8
通讯作者：
Owens, Lindsey L.
中科院分区：
文献类型：
--
作者：
Kelly, Sean D.;Opell, Brent D.;Owens, Lindsey L.
圆织蛛用蛋白质纤维支撑的规则间隔的胶滴形成的捕获螺旋来制造网来捕获猎物。每个液滴由外部水层和粘性粘弹性糖蛋白核心组成。水层中的有机和无机化合物使液滴具有吸湿性，并使液滴特征随环境湿度而变化。当液滴接触表面时，它们会粘附并随着昆虫的挣扎而延伸。因此，液滴的延展性对于捕获猎物来说与其粘附性一样重要。粗略的观察表明，液滴可以粘附，延伸，并从表面脱落几次，这个过程称为循环。我们的研究循环了四个物种Argiope aurantia，Neoscona crucifera，Verrucosa arenata和Larinioides cornutus的单个液滴。液滴在两种湿度下进行40次循环，以确定湿度如何影响液滴性能。我们假设液滴将继续执行，但性能会下降。液滴性能通过细丝长度和拉脱时液滴上的力、水体积和糖蛋白体积来表征。正如假设的那样，骑自行车降低了性能，特别是延展性和水体积。然而，湿度不影响对循环的响应。在自然环境中，水滴不会受到广泛的循环，但可重复使用性对圆织蜘蛛是有利的。此外，循环的能力，结合它们的环境响应性，使我们能够首次将orb weaver液滴描述为智能材料。
Orb weavers produce webs that trap prey using a capture spiral formed of regularly spaced glue droplets supported by protein fibers. Each droplet consists of an outer aqueous layer and an adhesive, viscoelastic glycoprotein core. Organic and inorganic compounds in the aqueous layer make droplets hygroscopic and cause droplet features to change with environmental humidity. When droplets contact a surface, they adhere and extend as an insect struggles. Thus, a droplet's extensibility is as important for prey capture as its adhesion. Cursory observations show that droplets can adhere, extend, and pull off from a surface several times, a process called cycling. Our study cycled individual droplets of four speciesArgiope aurantia, Neoscona crucifera, Verrucosa arenata, and Larinioides cornutus. Droplets were subjected to 40cycles at two humidities to determine how humidity affected droplet performance. We hypothesized that droplets would continue to perform, but that performance would decrease. Droplet performance was characterized by filament length and force on droplets at pull-off, aqueous volume, and glycoprotein volume. As hypothesized, cycling decreased performance, notably extensibility and aqueous volume. However, humidity did not impact the response to cycling. In a natural context, droplets are not subjected to extensive cycling, but reusability is advantageous for orb-weaving spiders. Moreover, the ability to cycle, combined with their environmental responsiveness, allows us to characterize orb weaver droplets as smart materials for the first time.