Improving understanding of triple-helical collagen structure, self-assembly, and supramolecular organization

从海绵到人类，胶原蛋白是动物体内最丰富的蛋白质。它是皮肤、骨骼、软骨和肌腱的主要成分，并在这些部位形成纤维。或者，它会形成一个类似支架的支撑层，称为基底膜，对其他组织的形成和维持至关重要。它的分子结构和它组装成组织或基膜的方式尚不清楚。我用两种技术来研究蛋白质。首先，用原子力显微镜扫描蛋白质表面的一个微小而尖锐的尖端，并根据其地形向上或向下移动。这提供了蛋白质表面特征的清晰图像，并允许我们观察诸如胶原纤维形成之类的事件。这种显微镜还可以用来测量分离两个相互作用的胶原蛋白所需的力的大小，这提供了关于两种蛋白质结合在一起的方式和它们相互作用的强度的有价值的信息。不幸的是，使用这种显微镜很难确定蛋白质的确切原子组成或产生测量力的相互作用原子。另一方面，通过核磁共振波谱，可以识别和研究蛋白质中的单个原子。这项技术可以建立胶原蛋白内原子的三维排列图，有助于解释胶原蛋白表面的显微图像。还可以确定与第二种胶原蛋白结合并引起测量的相互作用力的区域。因此，通过这两种技术获得的信息是高度互补的，但它们通常不会一起使用。我的研究项目将使用比全长天然胶原蛋白短的胶原蛋白模型。这些将被设计和生产，以适合这两种生物物理方法的研究。这将使我们能够填补胶原蛋白及其在动物（包括人类）中的功能方面的知识空白。

Collagen is the most abundant protein in animals ranging from sponges to humans. It is a major component of skin, bones, cartilage and tendons, where it forms fibres. Alternately, it forms a scaffold-like support layer called the basement membrane, crucial for formation and maintenance of other tissues. Its molecular structure and the way in which it assembles into tissue or basement membrane are not well understood.I use two techniques to study proteins. First, with an atomic force microscope, a tiny, sharp tip is scanned over a protein surface and moved up or down in response to its topography. This provides a clear picture of the features of the protein surface, and allows us to observe events such as collagen fibre formation. This microscope can also be used to measure the amount of force required to pull apart two interacting collagen proteins, which provides valuable information about the way the two proteins are held together and the strength of their interaction. Unfortunately, it is difficult to use this microscope to identify the exact atomic composition of the protein or the interacting atoms giving rise to the forces measured. With nuclear magnetic resonance spectroscopy, on the other hand, individual atoms within a protein can be identified and studied. This technique allows a picture of the three-dimensional arrangement of atoms within collagen to be built, assisting interpretation of the microscopic picture of the collagen surface. Regions involved in binding to a second collagen protein and causing measured interaction forces can also be identified. The information obtained by these two techniques is therefore highly complementary, but they are not routinely used together.My research program will use protein models of collagen shorter than the full-length natural collagen. These will be engineered and produced to be suitable for study by both of these biophysical methods. This will allow us to fill in major gaps in our knowledge of collagen and its function in animals, including humans.