The First Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 16 Jichang Road, Guangdong Province, 510405, Guangzhou, China.
Carbohydrate-Based Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai, 200031, China.
Glycoconj J. 2022 Jun;39(3):315-325. doi: 10.1007/s10719-021-10018-8. Epub 2021 Oct 26.
Furin is one of the nine-member proprotein convertase family. Furin cleaves proteins with polybasic residues, which includes many viral glycoproteins such as SARS-Cov-2 spike protein. The cleavage is required for the activation of the proteins. Currently, the mechanisms that regulate Furin activity remain largely unknown. Here we demonstrated that Furin is a novel heparin/heparan sulfate binding protein by the use of biochemical and genetic assays. The K is 9.78 nM based on the biolayer interferometry assay. Moreover, we found that sulfation degree, site-specific sulfation (N-sulfation and 3-O-sulfation), and iduronic acid are the major structural determinants for the binding. Furthermore, we found that heparin inhibits the enzymatic activity of Furin when pre-mixes heparin with either Furin or Furin substrate. We also found that the Furin binds with cells of different origin and the binding with the cells of lung origin is the strongest one. These data could advance our understanding of the working mechanism of Furin and will benefit the Furin based drug discovery such as inhibitors targeting the interaction between heparan sulfate and Furin for inhibition of viral infection.
弗林是九种蛋白原转化酶家族之一。弗林可切割具有多碱性残基的蛋白质，其中包括许多病毒糖蛋白，如 SARS-CoV-2 刺突蛋白。这种切割对于蛋白质的激活是必需的。目前，调节弗林活性的机制在很大程度上仍不清楚。在这里，我们通过生化和遗传分析证明了弗林是一种新型肝素/硫酸乙酰肝素结合蛋白。根据生物层干涉测定法，K 值为 9.78 nM。此外，我们发现硫酸化程度、位点特异性硫酸化（N-硫酸化和 3-O-硫酸化）和艾杜糖醛酸是结合的主要结构决定因素。此外，我们发现肝素在与弗林或弗林底物预混合时抑制弗林的酶活性。我们还发现弗林与不同来源的细胞结合，与肺源细胞的结合最强。这些数据可以增进我们对弗林作用机制的理解，并有助于基于弗林的药物发现，例如针对肝素硫酸酯和弗林相互作用的抑制剂，以抑制病毒感染。
