Zhang Miaomiao, Liu Ying, Cui Fengchao, Rankl Christian, Qin Juan, Guan Yanxue, Guo Xinyue, Zhang Bailin, Tang Jilin
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
College of Humanities & Information Changchun University of Technology, Changchun, 130122, P. R. China.
Nanoscale. 2020 Jun 11;12(22):11927-11935. doi: 10.1039/d0nr01570a.
Heparin, as an effective anticoagulant, has been increasingly used in clinical practice, but the binding characteristics and influence of exogenous heparin on heparin-affinity proteins in the body are still unclear. Vascular endothelial growth factor A (VEGF-A) is a kind of protein with heparin affinity involved in the pathogenesis and progression of many angiogenesis-dependent diseases including cancer. As an important step in the angiogenesis-related cascade, it is necessary to clarify the interaction between VEGF165 (the major form of VEGF-A) and heparin. In this work, we investigated this interaction based on single molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulation. From the SMFS study, binding forces between VEGF165 and heparin at different loading rates were quantified under near-physiological conditions. Meanwhile, the kinetic and thermodynamic parameters of the VEGF165/heparin complex dissociation process were also obtained. Results of MD simulation visually displayed the most likely binding conformation of VEGF165/heparin* complex, indicating that hydrogen bonding and hydrophobic interaction play a positive role in the binding between the two molecules. This work provides a new insight into the binding between VEGF165 and heparin and offers a research framework to study the interaction between heparin and multiple heparin affinity proteins, which is helpful for guiding the safe application of heparin in the clinic.
肝素作为一种有效的抗凝剂，在临床实践中得到了越来越广泛的应用，但外源性肝素对体内肝素亲和蛋白的结合特性及影响仍不清楚。血管内皮生长因子A（VEGF-A）是一种具有肝素亲和力的蛋白，参与包括癌症在内的许多血管生成依赖性疾病的发病机制和进展。作为血管生成相关级联反应中的重要一步，阐明VEGF165（VEGF-A的主要形式）与肝素之间的相互作用很有必要。在这项工作中，我们基于单分子力谱（SMFS）和分子动力学（MD）模拟研究了这种相互作用。通过SMFS研究，在近生理条件下定量了不同加载速率下VEGF165与肝素之间的结合力。同时，还获得了VEGF165/肝素复合物解离过程的动力学和热力学参数。MD模拟结果直观地展示了VEGF165/肝素复合物最可能的结合构象，表明氢键和疏水相互作用在这两种分子的结合中起积极作用。这项工作为VEGF165与肝素之间的结合提供了新的见解，并为研究肝素与多种肝素亲和蛋白之间的相互作用提供了一个研究框架，有助于指导肝素在临床上的安全应用。
