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Physico-chemical Studies of Spider's Silks Resistant to Ultra-violet Rays

蜘蛛丝抗紫外线的物理化学研究

基本信息

批准号：
10650889
负责人：
OSAKI Shigeyoshi
金额：
$ 2.05万
依托单位：
Nara Medical University (1999)Shimane University (1998)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

It is interesting to study the effects of ultraviolet rays upon the physical properties of spider silks because the ultraviolet (UV) rays are usually irradiated to the orb-web outdoors. Especially, it is important to measure the mechanical properties of dragline before and after the UV-irradiation to study the effects of the irradiation.The samples used here were the draglines from Nephila clavata at different stages of growth. The breaking strength and the elastic limit strength were determined from the stress-strain curve of dragline. The fine structures were also observed by electron microscope to determine the diameter of cross section of dragline.The author measured the mechanical properties of dragline at different stages of spider's growth before the UV were not incident. The safety coefficient, which is defined as the ratio of the elastic limit strength to the spider's weight, was determined to be about 2 for mature spiders and to be about 3 for immature spiders.UV-irradiation decreased the breaking strength while it did not change the elastic limit strength even after the UV-irradiation of a long time. It was made clear that the UV-irradiation decomposed the protein molecules constituting dragline and might decrease the molecular weight.The present study shows that the spider silks are stronger to the UV-rays than the silks from silkworm and that they are stronger for juvenile spiders than form mature ones.

研究紫外线对蜘蛛丝物理性能的影响是一件有趣的事情，因为紫外线通常照射在室外的圆网上。特别是，测量紫外线照射前后拖绳的力学性能，对研究紫外线照射对拖绳力学性能的影响具有重要意义。这里使用的样本是在不同生长阶段的鸭腹草的拖丝。根据拉索的应力-应变曲线确定了拉索的断裂强度和弹性极限强度。并通过电镜观察其精细结构，确定了拖绳横截面的直径。在紫外线未发生前，测定了蜘蛛生长不同阶段的拖丝的力学性能。安全系数定义为蜘蛛的弹性极限强度与蜘蛛的重量之比，确定成熟蜘蛛的安全系数约为2，未成熟蜘蛛的安全系数约为3。紫外线照射降低了材料的断裂强度，但即使经过长时间的紫外线照射，也没有改变材料的弹性极限强度。结果表明，紫外光照射可使构成拖丝的蛋白质分子分解，使拖丝的分子量降低。本研究表明，蜘蛛丝对紫外线的抵抗能力强于蚕丝，幼蛛的抵抗能力强于成年蜘蛛。