A comparison of the composition of silk proteins produced by spiders and insects
A comparison of the composition of silk proteins produced by spiders and insects
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DOI：
10.1016/s0141-8130(99)00006-9
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发表时间：
1999-03-01
影响因子：
8.2
通讯作者：
Pierce, NE
中科院分区：
文献类型：
--
作者：
Craig, CL;Hsu, M;Pierce, NE
与由摄入的氨基酸或代谢简单产生的蛋白质组成的蛋白质相比，高表达且由合成成本昂贵的氨基酸组成的蛋白质可能对生物体的能量资源造成更大的消耗。丝是所有蜘蛛和许多昆虫产生的高度表达的蛋白质。我们通过计算产生氨基酸成分所需的 ATP 量来比较节肢动物吐丝的代谢成本。虽然明确的结论需要节肢动物可利用氨基酸的饮食库的详细信息，但根据中央代谢途径，食草性鳞翅目幼虫吐出的丝所需的 ATP 合成量明显少于掠食性蜘蛛吐出的拖丝。虽然没有足够的数据来得出基于统计的结论，但对蜘蛛总科祖先和衍生类群的同源丝进行比较似乎表明了丝成本降低的进化趋势。然而，对所有蜘蛛类蜘蛛的拖丝合成成本进行比较表明，存在一种复杂的进化模式，不能仅归因于系统发育位置。我们提出，蜘蛛的多样化产丝系统（包括三种类型的蛋白胶和三种类型的丝素蛋白）是通过器官内竞争进化而来的，并且从同源腺体中提取的丝成分的分类特异性差异可能反映了有限或波动的氨基酸可用性。蜘蛛丝的不同功能特性可能是作用于不同多肽模板的选择的次要结果。 (C) 1999 Elsevier Science B.V. 保留所有权利。
Proteins that are highly expressed and composed of amino acids that are costly to synthesize are likely to place a greater drain on an organism's energy resources than proteins that are composed of ingested amino acids or ones that are metabolically simple to produce. Silks are highly expressed proteins produced by all spiders and many insects. We compared the metabolic costs of silks spun by arthropods by calculating the amount of ATP required to produce their component amino acids. Although a definitive conclusion requires detailed information on the dietary pools of amino acids available to arthropods, on the basis of the central metabolic pathways, silks spun by herbivorous, Lepidoptera larvae require significantly less ATP to synthesize than the dragline silks spun by predatory spiders. While not enough data are available to draw a statistically based conclusion, comparison of homologous silks across ancestral and derived taxa of the Araneoidea seems to suggest an evolutionary trend towards reduced silk costs. However, comparison of the synthetic costs of dragline silks across all araneomorph spiders suggests a complicated evolutionary pattern that cannot be attributed to phylogenetic position alone. We propose that the diverse silk-producing systems of the araneoid spiders (including three types of protein glues and three types of silk fibroin), evolved through intra-organ competition and that taxon-specific differences in the composition of silks drawn from homologous glands may reflect limited or fluctuating amino acid availability. The different functional properties of spider silks may be a secondary result of selection acting on different polypeptide templates. (C) 1999 Elsevier Science B.V. All rights reserved.