3月28日的《科学》（Science）杂志报道说，研究人员已经破解了一种有关生物材料的谜团——即鱿鱼是如何用其尖利如刀的喙状嘴来伤残其猎物但又不损害其喙状嘴所嵌入的肌肉组织？鱿鱼喙状嘴所面临的设计上的难题与无柄刀子相同，因为人们很难在不割伤自己的情况下来使用无柄的刀子。洪堡巨鱿（Dosidicus gigas）的喙状嘴是已知的完全为有机材料组成的最坚硬的物质之一，用该喙状嘴来击打猎物会将相当巨大的力量传导到其自身维系喙状嘴的软组织上。
根据Ali Miserez及其同事披露，该鱿鱼的喙状嘴之所以能够应付这些作用力原因在于，其切割端虽然既坚且硬但是它在越靠近喙状嘴附着的柔软肌肉组织时，它会逐渐变得越来越柔软且其可弯曲性也越来越大。研究人员非常费力地将喙状嘴的每一节段的特定化学组成进行了测定，并在每一点上将其与喙状嘴的力学性质进行配对。控制喙状嘴的坚硬程度是通过几丁质、水、富含组氨酸的蛋白质及一种叫做Dopa的化合物的比例变化来实现的。在一则相关的Perspective中，Phillip Messersmith探讨了Dopa在其他生物结构中的作用，以及研究人员为什么有兴趣在人工合成的材料中使用模拟生物材料性质的化合物。（来源：EurekAlert!中文版）
生物谷推荐原始出处：
（Science），Vol. 319. no. 5871, pp. 1816 - 1819，Ali Miserez，J. Herbert Waite
The Transition from Stiff to Compliant Materials in Squid Beaks
Ali Miserez,1,2,3 Todd Schneberk,2,3 Chengjun Sun,2,3 Frank W. Zok,1* J. Herbert Waite2,3*
The beak of the Humboldt squid Dosidicus gigas represents one of the hardest and stiffest wholly organic materials known. As it is deeply embedded within the soft buccal envelope, the manner in which impact forces are transmitted between beak and envelope is a matter of considerable scientific interest. Here, we show that the hydrated beak exhibits a large stiffness gradient, spanning two orders of magnitude from the tip to the base. This gradient is correlated with a chemical gradient involving mixtures of chitin, water, and His-rich proteins that contain 3,4-dihydroxyphenyl-L-alanine (dopa) and undergo extensive stabilization by histidyl-dopa cross-link formation. These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications.
1 Materials Department, University of California, Santa Barbara, CA 93106, USA.
2 Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
3 Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
