Wu G, Datar R H, Hansen K M, Thundat T, Cote R J, Majumdar A
Department of Mechanical Engineering, University of California, Berkeley, CA 94720, USA.
Nat Biotechnol. 2001 Sep;19(9):856-60. doi: 10.1038/nbt0901-856.
Diagnosis and monitoring of complex diseases such as cancer require quantitative detection of multiple proteins. Recent work has shown that when specific biomolecular binding occurs on one surface of a microcantilever beam, intermolecular nanomechanics bend the cantilever, which can be optically detected. Although this label-free technique readily lends itself to formation of microcantilever arrays, what has remained unclear is the technologically critical issue of whether it is sufficiently specific and sensitive to detect disease-related proteins at clinically relevant conditions and concentrations. As an example, we report here that microcantilevers of different geometries have been used to detect two forms of prostate-specific antigen (PSA) over a wide range of concentrations from 0.2 ng/ml to 60 microg/ml in a background of human serum albumin (HSA) and human plasminogen (HP) at 1 mg/ml, making this a clinically relevant diagnostic technique for prostate cancer. Because cantilever motion originates from the free-energy change induced by specific biomolecular binding, this technique may offer a common platform for high-throughput label-free analysis of protein-protein binding, DNA hybridization, and DNA-protein interactions, as well as drug discovery.
对癌症等复杂疾病的诊断和监测需要对多种蛋白质进行定量检测。最近的研究表明，当特定的生物分子在微悬臂梁的一个表面上发生结合时，分子间的纳米力学作用会使悬臂弯曲，这种弯曲可以通过光学手段检测到。尽管这种无标记技术很容易用于形成微悬臂阵列，但技术上的关键问题仍然不明确，即在临床相关条件和浓度下，它是否足够特异和灵敏以检测与疾病相关的蛋白质。例如，我们在此报告，不同几何形状的微悬臂已被用于在1mg/ml的人血清白蛋白（HSA）和人纤溶酶原（HP）背景下，检测浓度范围从0.2ng/ml到60μg/ml的两种形式的前列腺特异性抗原（PSA），这使其成为一种用于前列腺癌的临床相关诊断技术。由于悬臂的运动源于特定生物分子结合引起的自由能变化，该技术可能为蛋白质-蛋白质结合、DNA杂交、DNA-蛋白质相互作用的高通量无标记分析以及药物发现提供一个通用平台。
