Investigation of Biomolecular Reactions with Microcantilevers

我们建议利用微制悬臂梁的超灵敏度来研究分子过程，如DNA和蛋白质相互作用的杂交，微悬臂是为力镜开发的，作为成像工具。该项目取得了成功，我们现在有能力测量亚埃偏转，在苏黎世的Gimzewski团队在第二阶段率先将微悬臂用于成像以外的目的。在第一个例子中，他们确定了双金属悬臂梁作为热量计，其灵敏度超过了传统仪器。他们进一步证明，分子单链分子(金上的硫醇)自组装产生的应力足以使悬臂弯曲可测量的量。这两种效应，热和诱导应力，为我们研究分子反应提供了新的工具。我们在这个提案中的重点将放在DNA分子和蛋白质相互作用时发生的过程上。DNA杂交是克林顿总统在国情咨文演讲中提到的“基因芯片”技术中的一个基本步骤。在我们的计划中，我们将使用微悬臂梁来研究生物分子反应的三个方面：1)释放热，2)分子单分子层的形成诱导应力，3)DNA杂交过程中分子电荷的变化。我们怀疑第2项和第3项将是最有可能的候选者，但我们将审查所有这三个方面。我们相信，通过这些新工具，我们可以加深对分子反应的理解。

9811977QuateWe propose to exploit the ultra sensitivity of microfabricated cantilevers to study molecular processes such as hybridization of DNA and protein protein interactions, The microcantilever was developed for the Force Microscope as an instrument for imaging. That program was successful and we now have the capability measuring sub-Angstrom deflections, In a second phase the group with Gimzewski in Zurich has pioneered the use of the microcantilever for purposes other than imaging. In the first instance they determined that a bimetallic cantilever serves as a calorimeter with sensitivity exceeding that of conventional instruments. They have further demonstrated that the stress induced by the self-assembly of molecular monotayers (thiols on gold) is sufficient to bend the cantilever by measurable amounts. These two effects, heat and induced stress, give us new tools for the study of molecular reactions.Our focus in this proposal will be on the processes that occur when DNA molecules and Proteins interact. Hybridization of DNA is a fundamental step in the 'Gene Chip' technology as mentioned by President Clinton in his State of the Union address. In our proposal we will use the microcantilevers to study three aspects of biomolecular reactions: 1) evolved heat, 2) induced stress induced by the formation of molecular monolayers, and 3) the change in molecular charge during DNA hybridization. We suspect that items 2) and 3) will be the most likely candidates but we will examine all three aspects. We are confident that we can increase our understanding of molecular reactions with these new tools.***