Designing Spider Silk Proteins as Novel Biomaterials

描述(申请人提供)：蜘蛛丝已经进化了4.5亿多年，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，揭示了特定的氨基酸基序，这些基序已经被保存了超过1.25亿年。下一步从蜘蛛丝中产生生物材料的关键因素将是从当前的描述性数据转移到预测性知识。这些实验将提供预测性知识，从而能够为每种不同的医疗应用设计具有非常特定的弹性和强度属性的材料。这次更新旨在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)模数。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)优化纺丝和成膜工艺，使材料性能最大化。3)测试薄膜和纤维的力学性能。4)用红外光谱、圆二色谱和固体核磁共振确定了蛋白质在薄膜和纤维中的结构。5)将弹性和拉伸强度数据与每种类型母体的数量和顺序相关联，以产生弹性和拉伸强度特性的预测算法。6)在此基础上，将构建新的基因，以匹配韧带和肌腱所需的特性。过去两年的工作已经产生了许多新的基因、纯化的蛋白质和从这些蛋白质中提取的纤维。目前正在改进纤维纺丝和测试这些纤维。这个项目之所以意义重大，有几个原因。首先，它将提供对蜘蛛丝蛋白的弹性和拉伸强度的基本了解。具体地说，它将揭示是什么控制着弹性的数量和弹性模数，以及这两个因素是否可以以可预测的方式变化。其次，该项目将提高我们将蜘蛛丝用作生物材料的能力。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属性。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.