检测蛋白质相互作用的新工具可能为基因治疗和其他治疗带来有希望的途径

DALLAS (SMU) – SMU nanotechnology expert MinJun Kim and his team have developed a faster, 更精确的方法来检测特性和相互作用的单个蛋白质的快速, accurate, and real-time monitoring of virus-cell interactions. 

这可以为创新的医疗疗法和进步铺平道路 gene therapy 一种利用无害病毒修改人的基因来治疗或治愈疾病的技术. 

Beyond that, this research could also be used to detect and characterize other types of protein-protein interactions, 这可能会导致治疗方法的发展，从而调节相互作用，对身体产生不利影响, said Kim, the Robert C. 是新加坡管理大学莱尔工程学院的首席研究员 BAST Lab.   

A study published in the journal Nanoscale shows that this tiny device Kim’s team created 在靶向基因治疗中起作用的两种蛋白质——成纤维细胞生长因子(FGF-1)和肝素——何时相互结合，可以精确地实时测定. 

And unlike the ways protein-protein interactions are detected now, 该设备只需要很小的样本量来研究单个蛋白质的特性及其复杂的相互作用, saving time and cost for the analysis. 

Proteins are the workhorses that facilitate most biological processes in a cell. Often, it’s necessary for two or more proteins to bind with each other – meaning they’ve connected with each other as a result of biochemical events – to carry out certain functions. 

That’s the case with proteins FGF-1 and heparin. 

Together, these proteins have been shown to help a harmless virus called 腺相关病毒(AAV)是基因治疗的首选载体，它能附着在人体内合适的细胞受体上. 

病毒基因疗法使用像aav这样的病毒，将健康的基因拷贝传递到人体内 to replace or modify a disease-causing one. But the problem is that AAVs have several different types, or serotypes, 每一种病毒都有一种自然的偏好，即感染并在特定的组织类型中茁壮成长, such as those serving the heart or kidneys. 这意味着基因疗法要成功地将病毒的货物卸到预定的目标上, the right serotype of AAV needs to bond with the correct cell receptors. 

然而，目前对这种被称为向性的过程是如何确保这一点的了解还不够.     

“Thus, 更好地了解肝素和FGF-1的相互作用将有助于我们理解AAV基因治疗的趋向性,” which, in turn, could make it possible to target new gene therapies for specific diseases, Kim said. 

Kim’s team created and tested a device known as 一种固态纳米孔，它可以准确地判断肝素和FGF-1何时结合. 

How the device works

纳米粒子太小，肉眼看不到——大小从1纳米到100纳米(一米的十亿分之一)不等. 纳米材料可以自然产生，也可以通过工程设计来实现特定的功能, such as the delivery of drugs to various forms of cancer.

Each nanopore in this study was made from 12-nanometer-thick silicon nitride (SixNy) membranes, with a hole of roughly 17 nanometers in diameter drilled through it.

这些所谓的固态纳米孔能够判断肝素何时与FGF-1结合, because Kim and his team have calculated the electrical currents of three different scenarios: when only heparin is present in the sample; when only FGF-1 is present; and when there is an equal ratio of the two proteins.

How does the device know what the electrical current is?

Basically, 样品中的一个分子穿过装置上的一个小孔，这个小孔将两个含有 electrolyte solutions. 这会导致电流的波动，这可以被解码来检测 heparin-FGF-1 bonding.

Kim said, “这项研究的结果代表了为未来努力奠定基础的初步实验.”

他的最终目标是能够在另外两种蛋白质上使用固态纳米孔，这两种蛋白质对靶向基因治疗也很重要:aav与细胞表面受体的实际结合.

AAVs have a protein coat called a capsid that surrounds their genetic information, 基因治疗专家为了将新的健康基因引入人体而改变的是什么. 只有当衣壳与细胞受体(在细胞表面发现的另一种蛋白质)结合时，病毒和细胞才能连接起来，病毒的货物才能释放出来.

“靶向基因治疗的有效性取决于病毒衣壳和细胞表面受体之间的亲和力,” Kim explained. 

Kim wants to be able to use solid-state nanopores to measure that, 让人们更清楚地知道病毒何时成功地将其“货物”运送到人体内. 这是因为使用病毒基因疗法的一个关键障碍是无法测量由AAV传播的遗传物质的数量, potentially leading to overdosing or underdosing. 

In addition to making breakthroughs in gene therapy, lead study author Navod Thyashan, a graduate research assistant at SMU’s BAST, 值得注意的是，这些纳米孔也可以为其他新的医学治疗方法的开发奠定基础. It can be used with other proteins known to have a high affinity for bonding with each other, 允许治疗潜在地调节这些导致疾病的相互作用. 

“固态纳米孔(ssn)的直径可以从个位数纳米到数百纳米不等,” he said. “Thus, SSNs can be used in most biomolecule sensing applications, 只要我们选择合适的纳米孔直径来处理蛋白质.”

Helping Thyashan and Kim create the device were Madhav L. Ghimire, the Dean's Postdoctoral Fellow at SMU's Moody School of Graduate and Advanced Studies; and Sangyoup Lee, with the Bionic Research Center for the Korea Institute of Science and Technology.

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