The knowledge on how cells interact with microenvironment is particularly important in understanding the interaction of cancer cells with surrounding stroma, which affects cell migration, adhesion, and metastasis. The main cell surface receptors responsible for the interaction with extracellular matrix (ECM) are integrins, however, they are not the only ones. Integrins are accompanied to other molecules such as syndecans. The role of the latter has not yet been fully established. In our study, we would like to answer the question of whether integrins and syndecans, possessing similar functions, share also similar unbinding properties. By using single molecule force spectroscopy (SMFS), we conducted measurements of the unbinding properties of α_Vβ₁ and syndecan-4 in the interaction with vitronectin (VN), which, as each ECM protein, possesses two binding sites specific to integrins and syndecans. The unbinding force and the kinetic off rate constant derived from SMFS describe the stability of single molecular complex. Obtained data show one barrier transition for each complex. The proposed model shows that the unbinding of α_Vβ₁ from VN proceeds before the unbinding of SDC-4. However, despite different unbinding kinetics, the access to both receptors is needed for cell growth and proliferation.

关于细胞如何与微环境相互作用的知识对于理解癌细胞与周围基质的相互作用尤其重要，这会影响细胞迁移、粘附和转移。负责与细胞外基质 (ECM) 相互作用的主要细胞表面受体是整联蛋白，但它们并不是唯一的受体。整联蛋白伴随着其他分子，例如合成聚糖。后者的作用尚未完全确立。在我们的研究中，我们想回答具有相似功能的整合素和合成聚糖是否也具有相似的解结合特性的问题。通过使用单分子力谱 (SMFS)，我们对α _V β ₁的解结合特性进行了测量和 syndecan-4 在与玻连蛋白 (VN) 的相互作用中，作为每个 ECM 蛋白，它具有两个对整合素和多聚体具有特异性的结合位点。来自 SMFS 的解结合力和动力学解离速率常数描述了单分子复合物的稳定性。获得的数据显示了每个复合物的一个屏障转变。所提出的模型表明，α _V β ₁与 VN 的解除绑定在 SDC-4 解除绑定之前进行。然而，尽管解结合动力学不同，但细胞生长和增殖都需要接触这两种受体。