Designing Spider Silk Proteins as Novel Biomaterials

描述（由申请人提供）：蜘蛛丝已经进化了超过4.5亿年，其抗拉强度大于钢，弹性大于尼龙。许多蜘蛛丝基因已经被克隆和测序，揭示了已经保存了超过1.25亿年的特定氨基酸基序。下一步从蜘蛛丝中产生生物基材料的关键因素将是从目前的描述性数据转向预测性知识。这些实验将提供预测知识，使材料的设计具有非常具体的弹性和强度特性，为每个不同的医疗应用。这次更新的目的是继续测试两个基本假设和工程概念。1)材料的弹性将与弹性图案的数量成正比。2)改变弹性区域的顺序会改变弹性（杨氏）模量。这里描述了一个简短的工作计划。1)继续蛋白的表达和纯化。2)优化纺丝和制膜工艺，最大限度地提高所需材料的性能。3)测试薄膜和纤维的力学性能。4)通过FTIR、CD和固态NMR测定膜和纤维中蛋白质的结构。5)将弹性和抗拉强度数据与每种基序的数量和序列相关联，从而产生弹性和抗拉强度性能的预测算法。在此基础上，将构建出符合韧带和肌腱所需特性的新基因。过去两年的工作已经产生了许多新的基因，纯化的蛋白质和纤维。纤维纺纱的改进和对这些纤维的测试目前正在进行中。由于几个原因，这个项目非常重要。首先，它将提供一个基本的了解弹性和抗拉强度在蜘蛛丝蛋白。具体来说，它将揭示控制弹性和弹性模量的因素，以及这两个因素是否可以以可预测的方式变化。第二，这个项目将提高我们使用蜘蛛丝作为生物材料的能力。如果我们的假设是正确的，我们将学习如何通过控制蛋白质序列来控制弹性和其他材料性能。蜘蛛丝的可能应用范围从人造韧带和肌腱到烧伤绷带，再到多种用途的复合材料。

DESCRIPTION (provided by applicant): Spider silk, which has been evolving for over 450 million years, has a tensile strength greater than steel and elasticity greater than nylon. A number of spider silk genes have been cloned and sequenced revealing specific amino acid motifs that have been conserved for over 125 million years. The key element in taking the next step toward generating bio-based materials from spider silks will be to move from the current descriptive data to predictive knowledge. These experiments will provide the predictive knowledge enabling the design of materials with very specific elastic and strength properties for each different medical application. This renewal is designed to continue testing two basic hypotheses and engineering concepts. 1) The elasticity of the materials will be proportional to the number of elastic motifs. 2) Varying the sequence of the elastic regions will vary elastic (Young's) modulus. A brief workplan is described here. 1) Continue the expression and purification of the proteins. 2) Optimize the spinning and film making process to maximize desired materials properties. 3) Test mechanical properties of films and fibers. 4) Determine the structure of the protein in films and fibers by FTIR, CD and solid state NMR. 5) The elasticity and tensile strength data will be correlated with the number and sequence of each type of motif to produce a prediction algorithm for elastic and tensile strength properties. 6) Based on 5) new genes will be constructed to match the properties needed for ligament and tendons. The past two years of work have produced a number of new genes, purified proteins and fibers from those proteins. Improvements in fiber spinning and testing of those fibers is currently in progress. This project is highly significant for several reasons. First it will provide a basic understanding of elasticity and tensile strength in spider silk proteins. Specifically, it will reveal what controls the amount of elasticity and elastic modulus and if these two factors can be varied in a predictable way. Second this project will advance our ability to use spider silk as a biomaterial. If our hypotheses are correct we will learn how to control the elasticity and other materials properties by controlling the protein sequence. Possible applications of spider silk range from artificial ligaments and tendons to bandages for burns to composite materials for multiple applications.