该研究团队成功开发出一种超拉伸张力传感器（OTS），该传感器能在生理条件下进行更精确的力测量，即便在机械活性区域也具备单分子检测灵敏度。研究人员利用串联的OTSs进行了实验，并发现整合素的载药速率介于0.5至4皮牛顿/秒之间。更令人惊讶的是，在白细胞中的载药速率竟是上皮细胞的3倍。
据悉，细胞通过表面受体与环境连接，并在各种细胞过程中利用受体-配体键的物理张力。单分子技术通过测量“断键力”揭示了键的强度，但人们早就认识到断键力取决于载药速率——力增加的速度。因此，需要测量生理载药速率，以揭示单个键在其功能背景下的机械强度。
附：英文原文
Title: Determination of single-molecule loading rate during mechanotransduction in cell adhesion
Author: Myung Hyun Jo, Paul Meneses, Olivia Yang, Claudia C. Carcamo, Sushil Pangeni, Taekjip Ha
Issue&Volume: 2024-03-22
Abstract: Cells connect with their environment through surface receptors and use physical tension in receptor–ligand bonds for various cellular processes. Single-molecule techniques have revealed bond strength by measuring “rupture force,” but it has long been recognized that rupture force is dependent on loading rate—how quickly force is ramped up. Thus, the physiological loading rate needs to be measured to reveal the mechanical strength of individual bonds in their functional context. We have developed an overstretching tension sensor (OTS) to allow more accurate force measurement in physiological conditions with single-molecule detection sensitivity even in mechanically active regions. We used serially connected OTSs to show that the integrin loading rate ranged from 0.5 to 4 piconewtons per second and was about three times higher in leukocytes than in epithelial cells.
Source: https://www.science.org/doi/10.1126/science.adk6921